Methods for Refracturing a Subterranean Formation

Abstract

Methods for refracturing a subterranean formation via a hydrocarbon well that includes a downhole tubular extending within a wellbore formed within the subterranean formation. The methods include positioning a plurality of isolation structures within a tubular conduit defined by the downhole tubular to define a plurality of spaced-apart stimulation zones. The downhole tubular includes a plurality of spaced-apart existing perforations. The methods also include stimulating an initial region of the subterranean formation, which is associated with an initial stimulation zone of the plurality of spaced-apart stimulation zones, via an initial subset of the plurality of spaced-apart existing perforations and subsequently sealing the initial subset of the plurality of spaced-apart existing perforations. The methods further include establishing fluid communication between the initial stimulation zone and an adjacent stimulation zone and stimulating an adjacent region of the subterranean formation that is associated with the adjacent stimulation zone.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser. No. 62/525,041 filed Jun. 26, 2017 titled “Methods for Refracturing a Subterranean Formation,” and is related to and will claim benefit of U.S. Provisional Application Ser. No. 62/463,389 filed Feb. 24, 2017 titled “Method for Well Stimulation,” the disclosures of which are incorporated herein by reference in their entireties.

This application is related to U.S. Provisional Application Ser. No. 62/525,043 filed Jun. 26, 2017 titled “Methods for Refracturing a Subterranean Formation Using Shearable Ball Seats for Zone Isolation,” the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to methods for refracturing a subterranean formation and more specifically to methods for refracturing a subterranean formation via a hydrocarbon well that includes a downhole tubular extending within a wellbore formed within the subterranean formation.

BACKGROUND OF THE DISCLOSURE

Conventional refracturing operations generally have been performed by bullheading a stimulant fluid stream, which may include a stimulant fluid, a proppant, and/or a proppant slurry, into a wellbore while an entire lateral is open, simultaneously pumping the stimulant fluid stream through all perforations. Such conventional refracturing operations colloquially are referred to in the industry as a “pump and pray” operation, as they provide little control over which perforation(s) actually receive the stimulant fluid stream and/or which region(s) of a subterranean formation are refractured.

In a variant of these conventional refracturing operations, and after pumping the stimulant fluid stream for a given period of time, a number of ball sealers, chemical diverters, particulate diverters, and/or other sealing devices may be deployed within the hydrocarbon well with the goal of sealing the perforations that are most receptive of the stimulant fluid stream. Subsequently, the stimulant fluid stream may be pumped through the remaining perforations to re-stimulate other region(s) of the subterranean formation. This methodology, while simple and generally low-cost, suffers from an inability to target the stimulant fluid stream to specific region(s) of the subterranean formation and/or to provide high stimulant fluid stream injection rates through specific perforation(s).

Another conventional refracturing operation involves the use of coiled tubing, together with a straddle packer assembly, to supply the stimulant fluid stream to desired region(s) of the subterranean formation. While more targeted than “pump and pray,” coiled tubing also suffers from low injection rates (due to the small diameter of the coiled tubing and associated friction pressure losses), high costs, and operational risks.

Yet another conventional refracturing operation involves setting a liner across existing perforations. The liner may have a defined or expandable diameter and may be cemented or not. After the liner is set, this conventional refracturing operation is similar to initial completion of the well. Such a conventional refracturing operation is operationally difficult and very costly.

While the above-described conventional refracturing operations collectively may provide the ability to refracture many subterranean formations, they suffer from the above-described limitations. Thus, there exists a need for improved methods for refracturing a subterranean formation.

SUMMARY OF THE DISCLOSURE

Methods for refracturing a subterranean formation via a hydrocarbon well that includes a downhole tubular extending within a wellbore formed within the subterranean formation. The methods include positioning a plurality of isolation structures within a tubular conduit defined by the downhole tubular to define a plurality of spaced-apart stimulation zones within the tubular conduit. The downhole tubular includes a plurality of spaced-apart existing perforations. The plurality of spaced-apart existing perforations provides fluid communication between the tubular conduit and the subterranean formation, and each stimulation zone in the plurality of spaced-apart stimulation zones includes a corresponding subset of the plurality of spaced-apart existing perforations.

Subsequent to the positioning, the methods also include stimulating an initial region of the subterranean formation. The initial region of the subterranean formation is associated with an initial stimulation zone of the plurality of spaced-apart stimulation zones. The initial stimulation zone includes an initial subset of the plurality of spaced-apart existing perforations, and the stimulating the initial region includes injecting a stimulant fluid from a surface region, via the tubular conduit, through the initial subset of the plurality of spaced-apart existing perforations, and into the subterranean formation. The methods also include resisting flow of the stimulant fluid through stimulation zones that are downhole from the initial stimulation zone during injection of the stimulant fluid through the initial subset of the plurality of spaced-apart existing perforations. The methods then include sealing the initial subset of the plurality of spaced-apart existing perforations.

The methods further include establishing fluid communication between the initial stimulation zone and an adjacent stimulation zone within the tubular conduit while maintaining the sealing of the initial subset of the plurality of spaced-apart existing perforations. The adjacent stimulation zone is downhole from the initial stimulation zone.

The methods also include stimulating an adjacent region of the subterranean formation that is associated with the adjacent stimulation zone. The adjacent stimulation zone includes an adjacent subset of the plurality of spaced-apart existing perforations. The stimulating the adjacent region of the subterranean formation includes flowing the stimulant fluid from the surface region, via the tubular conduit, through the initial stimulation zone, through the adjacent subset of the plurality of spaced-apart existing perforations, and into the subterranean formation while resisting flow of the stimulant fluid through stimulation zones that are downhole from the adjacent stimulation zone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic example of hydrocarbon wells that may be utilized to perform the methods according to the present disclosure.

FIG. 2 is a flowchart depicting methods, according to the present disclosure, for refracturing a subterranean formation via a hydrocarbon well.

FIG. 3 illustrates an example of a portion of the methods of FIG. 2.

FIG. 4 illustrates another example of a portion of the methods of FIG. 2.

FIG. 5 illustrates another example of a portion of the methods of FIG. 2.

FIG. 6 illustrates another example of a portion of the methods of FIG. 2.

FIG. 7 illustrates another example of a portion of the methods of FIG. 2.

FIG. 8 illustrates another example of a portion of the methods of FIG. 2.

FIG. 9 illustrates another example of a portion of the methods of FIG. 2.

FIG. 10 illustrates another example of a portion of the methods of FIG. 2.

FIG. 11 illustrates another example of a portion of the methods of FIG. 2.

FIG. 12 illustrates another example of a portion of the methods of FIG. 2.

FIG. 13 illustrates another example of a portion of the methods of FIG. 2.

FIG. 14 illustrates another example of a portion of the methods of FIG. 2.

FIG. 15 illustrates another example of a portion of the methods of FIG. 2.

FIG. 16 illustrates another example of a portion of the methods of FIG. 2.

FIG. 17 illustrates another example of a portion of the methods of FIG. 2.

FIG. 18 illustrates another example of a portion of the methods of FIG. 2.

FIG. 19 illustrates another example of a portion of the methods of FIG. 2.

FIG. 20 illustrates another example of a portion of the methods of FIG. 2.

FIG. 21 illustrates another example of a portion of the methods of FIG. 2.

FIG. 22 illustrates another example of a portion of the methods of FIG. 2.

DETAILED DESCRIPTION AND BEST MODE OF THE DISCLOSURE

FIGS. 1-22 provide examples of methods 200, according to the present disclosure, of hydrocarbon wells 40 that may be utilized to perform methods 200, and/or of various steps that may be performed during methods 200. Elements that serve a similar, or at least substantially similar, purpose are labeled with like numbers in each of FIGS. 1-22, and these elements may not be discussed in detail herein with reference to each of FIGS. 1-22. Similarly, all elements may not be labeled in each of FIGS. 1-22, but reference numerals associated therewith may be utilized herein for consistency. Elements, components, and/or features that are discussed herein with reference to one or more of FIGS. 1-22 may be included in and/or utilized with any of FIGS. 1-22 without departing from the scope of the present disclosure. In general, elements that are likely to be included in a particular embodiment are illustrated in solid lines, while elements that are optional are illustrated in dashed lines. However, elements that are shown in solid lines may not be essential and, in some embodiments, may be omitted without departing from the scope of the present disclosure.

FIG. 1 is a schematic example of hydrocarbon wells 40 that may be utilized with, or to perform, methods 200 according to the present disclosure, which are discussed in more detail herein with reference to FIG. 2. Hydrocarbon wells 40 include a downhole tubular 60 that defines a tubular conduit 62. Downhole tubular 60 extends within a wellbore 50 that extends within a subterranean formation 30. Wellbore 50 also may be referred to herein as extending within a subsurface region 20, as extending between a surface region 10 and subsurface region 20, and/or as extending between surface region 10 and subterranean formation 30. Examples of downhole tubular 60 include any suitable tube, casing segment, casing string, casing, liner segment, liner string, and/or liner that may extend within wellbore 50, that may extend between surface region 10 and subterranean formation 30, and/or that may be hung off, within wellbore 50, below the surface region and/or within the subsurface region.

Wellbore 50 may define an uphole direction 52, which may point and/or extend, along the wellbore, in a direction that generally is toward an uphole end 42 of the hydrocarbon well and/or away from a downhole, or toe, end 44 of the hydrocarbon well. Wellbore 50 also may define a downhole direction 54, which may point and/or extend, along the wellbore, in a direction that generally is away from uphole end 42 and/or is toward downhole end 44. Wellbore 50 also may have and/or define a heel, or heel region, 43. Heel 43 may include and/or be a transition region between a vertical portion, or region, of the wellbore and a horizontal, or deviated, portion, or region, of the wellbore.

Wellbore 50 may have any suitable shape and/or trajectory within subsurface region 20. As examples, wellbore 50 may include one or more of a vertical region, a deviated region, and/or a horizontal, or at least substantially horizontal, region.

Hydrocarbon wells 40 may include a plurality of isolation structures 90, which may be positioned within tubular conduit 62. Isolation structures 90 may be spaced-apart from one another along a length of the tubular conduit and/or may form, define, delineate, and/or bound a plurality of discrete, distinct, and/or spaced-apart stimulation zones 110.

Downhole tubular 60 may include a plurality of spaced-apart existing perforations 70, which also may be referred to herein as a plurality of perforations 70. Existing perforations 70 previously may have been utilized to stimulate subterranean formation 30 and/or to produce a hydrocarbon from the subterranean formation. Existing perforations 70 may be formed and/or may be present within downhole tubular 60 prior to performing, or prior to initiation of, methods 200 that are disclosed herein. Each stimulation zone 110 may include a corresponding subset of the plurality of spaced-apart existing perforations. As examples, an initial stimulation zone 112 may include an initial subset 72 of the plurality of spaced-apart existing perforations, an adjacent stimulation zone 114 may include an adjacent subset 74 of the plurality of spaced-apart existing perforations, and/or a subsequent stimulation zone 116 may include a subsequent subset 76 of the plurality of spaced-apart existing perforations. A most uphole subset of existing perforations 70 may extend within heel region 43, and a most downhole subset of existing perforations 70 may extend within toe region 44.

As illustrated in dashed lines in FIG. 1, downhole tubular 60 also may include a plurality of spaced-apart new perforations 80. New perforations 80 may be formed during, or as a result of, methods 200. Additionally or alternatively, new perforations 80 may be formed within the downhole tubular subsequent to stimulation of the subterranean formation via existing perforations 70 and/or subsequent to production of the hydrocarbon from the subterranean formation via the existing perforations.

Isolation structures 90 may include corresponding isolation devices 100, and an initial isolation device 102 may extend between, or delineate, initial stimulation zone 112 and adjacent stimulation zone 114. An adjacent isolation device 104 may extend between, or delineate, adjacent stimulation zone 114 and subsequent stimulation zone 116. A subsequent isolation device 106 may extend between, or delineate, subsequent stimulation zone 116 and a remainder of tubular conduit 62 that extends downhole, or in downhole direction 54, from the subsequent stimulation zone.

Isolation structures 90 may include any suitable structure that may form, define, or delineate stimulation zones 110. Additionally or alternatively, isolation structures may include any suitable structure that may, or that may be utilized to, isolate, fluidly isolate, hydraulically isolate, and/or selectively isolate stimulation zones 110 from one another, at least within tubular conduit 62.

As an example, and as illustrated in dashed lines in FIG. 1 and in more detail in FIGS. 6, 9, 12, and 15, isolation structures 90 may include and/or be a frangible isolation structure 92. Frangible isolation structures 92 may be configured to selectively shatter, break apart, and/or disintegrate, such as upon receipt of, or experiencing, a shockwave, a pressure spike, and/or another suitable transition signal. Stated another way, isolation device 100 of frangible isolation structures 92 may include and/or be a frangible or destructible isolation device 100, such as a glass and/or ceramic isolation device that is configured to selectively shatter or break such as responsive to receipt of an actuation signal or in the presence of a selected pressure.

As another example, and as illustrated in dashed lines in FIG. 1 and in more detail in FIGS. 7, 10, 13, and 16, isolation structures 90 may include an isolation device seat 94 that is configured to receive, to selectively receive, to release, and/or to selectively release isolation device 100. Under these conditions, isolation device 100 also may be referred to herein as, or may be, an isolation ball 100, and isolation device seat 94 also may be referred to herein as, or may be, an isolation ball seat 94.

During re-fracturing of hydrocarbon wells 40 utilizing methods 200, and as discussed in more detail herein with reference to methods 200 of FIG. 2, wellbore 50 and/or tubular conduit 62 may be cleaned-out and/or cleared. The terms “cleanout” and/or “clearing” and/or “cleaning” may be used interchangeably, referring to the processes related to the removal of any obstructions and/or fill within the through bore of tubular conduit, such as, for example, frac sand, proppant, produced formation sand or other media, frac plugs, seats, perforating gun debris, ball sealers, perforation sealing devices and structures, staging material, scale, paraffin, and any other debris, etc. Subsequently, a plurality of isolation structures 90 may be positioned within tubular conduit 62 to define stimulation zones 110. Initial isolation device 102 may be, or may be placed in, a closed state in which the initial isolation device includes isolation structure 90 and resists fluid flow from initial stimulation zone 112 and into portions of tubular conduit 62 that are downhole from the initial stimulation zone. Subsequently, a stimulant fluid 120 may be provided to tubular conduit 62, such as from surface region 10. The stimulant fluid may flow into subterranean formation 30 via initial subset 72 of existing perforations 70 and/or via an initial subset 82 of new perforations 80, when present, to stimulate an initial region 32 of the subterranean formation.

Subsequently, initial subset 72 of existing perforations 70 and/or initial subset 82 of new perforations 80, when present, may be sealed, such as via and/or utilizing one or more sealing devices 130, which also may be referred to herein as initial sealing devices 132. This may include sealing all of the initial subset of the plurality of spaced-apart existing perforations and all of the initial subset of the new perforations, when present. Alternatively, this may include a multi-step process that includes sealing a most fluid-receptive fraction of the initial subset of the plurality of existing perforations and/or of the initial subset of the plurality of new perforations. Subsequently, additional stimulant fluid may be injected into the subterranean formation via one or more perforations that remain open prior to sealing all of the initial subset of the existing perforations and all of the initial subset of the new perforations, when present. Such a process is discussed in more detail herein.

Subsequently, fluid communication may be established between initial stimulation zone 112 and adjacent stimulation zone 114, and the process may be repeated to stimulate an adjacent region 34 of the subterranean formation utilizing adjacent subset 74 of existing perforations 70 and/or an adjacent subset 84 of new perforations 80, when present. Then, perforations present within adjacent stimulation zone 114 may be sealed with corresponding adjacent sealing devices 134.

This process may be repeated any suitable number of times to stimulate any suitable number of regions of subterranean formation 30. As an example, fluid communication may be established between adjacent stimulation zone 114 and subsequent stimulation zone 116, and subsequent region 36 of the subterranean formation may be stimulated via subsequent subset 76 of the plurality of spaced-apart existing perforations and/or via subsequent subset 86 of the plurality of new perforations. Then, perforations present within subsequent stimulation zone 116 may be sealed with corresponding subsequent sealing devices 136.

Sealing devices 130 may include and/or be any suitable structure that may be adapted, configured, designed, sized, and/or constructed to flow into contact with existing perforations 70, to seal existing perforations 70, to flow into contact with new perforations 80, and/or to seal new perforations 80. Examples of sealing devices 130 include ball sealers, conformable, knotted or tentacular perforation sealing device (collectively hereafter referred to as “conformable sealers”), beads, poly lactic acid beads, fibers, poly lactic acid fibers, rods, and/or poly lactic acid rods.

FIG. 2 is a flowchart depicting methods 200, according to the present disclosure, for refracturing a subterranean formation via a hydrocarbon well, such as one or more of hydrocarbon wells 40 of FIG. 1. FIGS. 3-22 illustrate examples of portions of methods 200 of FIG. 2. More specifically, FIG. 3 illustrates cleaning of a tubular conduit of the hydrocarbon well, and FIG. 4 illustrates formation of new perforations within a downhole tubular that defines the tubular conduit. FIGS. 5, 8, 11, 14, and 17 schematically illustrate methods 200, while FIGS. 6, 9, 12, 15, and 18 illustrate methods 200 performed utilizing frangible isolation structures. FIGS. 7, 10, 13, 16, and 18 illustrate methods 200 performed utilizing isolation device seats configured to receive corresponding isolation devices, and FIG. 19 illustrates a re-fractured subterranean formation subsequent to having methods 200 performed therein. In addition, FIGS. 20-22 illustrate a multi-step sealing process that may be utilized during methods 200.

Methods 200 may include cleaning a tubular conduit at 205 and/or adding new perforations at 210. Methods 200 include positioning a plurality of isolation structures at 215 and may include positioning an initial isolation device at 220. Methods 200 also include stimulating an initial region of the subterranean formation at 225, sealing an initial subset of a plurality of perforations at 230, and/or establishing fluid communication between an initial stimulation zone and an adjacent stimulation zone at 235. Methods 200 further may include positioning an adjacent isolation device at 240 and include stimulating an adjacent region of the subterranean formation at 245. Methods 200 also may include sealing an adjacent subset of the plurality of perforations at 250, establishing fluid communication between the adjacent stimulation zone and a subsequent stimulation zone at 255, stimulating a subsequent region of the subterranean formation at 260, and/or clearing the tubular conduit at 265.

Cleaning the tubular conduit at 205 may include cleaning the tubular conduit in any suitable manner and may be performed prior to the positioning at 215. As an example, the cleaning at 205 may include flushing solids, solid matter, and/or particulate matter from the tubular conduit. As another example, the cleaning at 205 may include removing downhole equipment and/or devices from the tubular conduit. As an additional example, the cleaning at 205 may be performed utilizing coiled tubing. An example of the cleaning at 205 is illustrated in FIG. 3, with tubular conduit 62 being free, or at least substantially free, of solids, solid matter, particulate matter, and/or downhole equipment and/or devices subsequent to the cleaning at 205.

As discussed herein with reference to FIG. 1, the downhole tubular may include a plurality of existing perforations. Under these conditions, the adding new perforations at 210, which also may be referred to herein as re-perforating the downhole tubular, may include forming, generating, and/or defining a plurality of spaced-apart new perforations within the downhole tubular. The plurality of spaced-apart new perforations may be utilized to permit stimulation and/or fracturing of new and/or different portions and/or region(s) of the subterranean formation, as discussed in more detail herein. The adding at 210, when utilized, may be performed prior to the positioning at 215, prior to the positioning at 220, and/or prior to the stimulating at 225. An example of the adding at 210 is illustrated in FIG. 4, with downhole tubular 60 including both a plurality of existing perforations 70 and a plurality of new perforations 80.

The adding at 210 may be accomplished in any suitable manner. As examples, the adding at 210 may be performed utilizing any suitable autonomous and/or wireline-attached perforation gun and/or perforation device, such as a shape charge perforation device.

Positioning the plurality of isolation structures at 215 may include positioning the plurality of isolation structures within the tubular conduit that is defined by the downhole tubular. The positioning at 215 additionally or alternatively may include positioning the plurality of isolation structures to form, define, and/or delineate a plurality of spaced-apart stimulation zones within the tubular conduit. As discussed, the downhole tubular may include a plurality of spaced-apart existing perforations that provides fluid communication between the tubular conduit and the subterranean formation. Under these conditions, the positioning at 215 may include positioning the plurality of isolation structures such that each stimulation zone in the plurality of spaced-apart stimulation zones includes a corresponding subset of the plurality of spaced-apart existing perforations.

Examples of the positioning at 215 are illustrated in FIGS. 5-7. FIG. 5 illustrates the broad concept of positioning a plurality of isolation structures 90 within a tubular conduit 62 to define a plurality of spaced-apart stimulation zones 110 within the tubular conduit. In the illustrated example, the plurality of spaced-apart stimulation zones includes an initial stimulation zone 112, which includes an initial subset 72 of the plurality of spaced-apart existing perforations 70, an adjacent stimulation zone 114, which includes an adjacent subset 74 of the plurality of spaced-apart existing perforations 70, and a subsequent stimulation zone 116, which includes a subsequent subset 76 of the plurality of spaced-apart existing perforations 70.

FIG. 6 illustrates that isolation structures 90 may include and/or be frangible isolation structures 92 that include frangible isolation devices 100. Each frangible isolation structure 92 may resist fluid flow, within the tubular conduit, therepast, may resist fluid flow from an uphole region of the tubular conduit to a downhole region of the tubular conduit, and/or may resist fluid flow from the downhole region of the tubular conduit to the uphole region of the tubular conduit. Thus, and as illustrated, stimulation zones 110 may be fluidly and/or hydraulically isolated from one another, at least within tubular conduit 62, subsequent to the positioning at 215. When the positioning at 215 includes positioning frangible isolation structures 92, the positioning at 215 may include positioning an initial frangible isolation device 102 between initial stimulation zone 112 and adjacent stimulation zone 114 and/or positioning an adjacent frangible isolation device 104 between adjacent stimulation zone 114 and subsequent stimulation zone 116.

FIG. 7 illustrates that isolation structures 90 may include and/or be isolation device seats 94 that are configured to receive the isolation device. Under these conditions, and as illustrated, stimulation zones 110 may be in fluid and/or hydraulic communication with one another until a respective isolation device is positioned upon a corresponding isolation device seat 94. When the positioning at 215 includes positioning isolation device seats 94, the positioning at 215 may include positioning an initial isolation device seat between initial stimulation zone 112 and adjacent stimulation zone 114 and/or positioning a subsequent isolation device seat between adjacent stimulation zone 114 and subsequent stimulation zone 116.

The positioning at 215 may be accomplished in any suitable manner. As an example, the positioning at 215 may include operatively engaging a given isolation structure within a corresponding region of the downhole tubular. As another example, the positioning at 215 may include positioning such that the plurality of isolation structures is spaced-apart from one another along a length of the tubular conduit. As yet another example, the positioning at 215 may include positioning such that each adjacent pair of isolation structures separates, bounds, and/or delineates a corresponding stimulation zone of the plurality of spaced-apart stimulation zones within the tubular conduit. As another example, the positioning at 215 may include flowing, within the tubular conduit and/or from a surface region, each isolation structure in the plurality of isolation structures to the corresponding region of the downhole tubular. As additional examples, the positioning at 215 may include autonomously positioning at least a subset of the plurality of isolation structures, positioning at least a subset of the plurality of isolation structures utilizing a wireline, positioning at least a subset of the plurality of isolation structures utilizing jointed pipe, utilizing coiled tubing, and/or utilizing a tractor.

It is within the scope of the present disclosure that, subsequent to the positioning at 215, the isolation structures may include any suitable spacing, relative spacing, and/or average spacing therebetween. As examples, a spacing, or an average spacing, between adjacent isolation structures may be at least 5 meters, at least 8 meters, at least 10 meters, at least 20 meters, at least 50 meters, at least 100 meters, at least 200 meters, at least 300 meters, at least 400 meters, at least 500 meters, at most 3000 meters, at most 2000 meters, at most 1000 meters, and/or at most 500 meters.

The positioning at 215 may include positioning the plurality of isolation structures in any suitable order, in any suitable relative order, and/or with any suitable sequence. As an example, the positioning at 215 may include sequentially positioning the plurality of isolation structures within the tubular conduit to define the plurality of spaced-apart stimulation zones. The sequentially positioning may include sequentially positioning such that each isolation structure in the plurality of isolation structures is uphole from a, or from all, previously positioned isolation structures of the plurality of isolation structures.

When the positioning at 215 includes positioning the plurality of isolation structures in the form of the plurality of isolation device seats, methods 200 further may include the positioning, at 220, the initial isolation device, which may be performed prior to the stimulating at 225. The positioning at 220 may include positioning the initial isolation device on the initial isolation device seat. When combined with a corresponding isolation device, the isolation device seats may be configured to resist fluid flow from an uphole region of the tubular conduit, which is uphole from the isolation device seat, to and/or toward a downhole region of the tubular conduit, which is downhole from the isolation device seat. Thus, the positioning at 220 may include fluidly and/or hydraulically isolating the initial stimulation zone from the adjacent stimulation zone and/or from other stimulation zones that are downhole from the initial stimulation zone. However, fluid communication still may be present among the other stimulation zones that are downhole from the initial stimulation zone. This is illustrated in FIG. 10, with initial isolation device 102 restricting fluid communication between initial stimulation zone 112 and adjacent stimulation zone 114.

The positioning at 220 may be accomplished in any suitable manner. As an example, the positioning at 220 may include flowing the initial isolation device into contact with the initial isolation device seat. As another example, the positioning at 220 may include seating the initial isolation device on the initial isolation device seat. The initial isolation device may include and/or be any suitable structure, an example of which includes an initial isolation ball.

Stimulating the initial region of the subterranean formation at 225 may include stimulating a region of the subterranean formation that is associated with the initial stimulation zone. Stated another way, the initial region of the subterranean formation may surround the initial stimulation zone, may contain the initial stimulation zone, and/or may be in fluid communication with the initial stimulation zone via the initial subset of the plurality of spaced-apart existing perforations.

The stimulating at 225 may be accomplished in any suitable manner. As an example, the stimulating at 225 may include injecting a stimulant fluid from a surface region, via the tubular conduit, through the initial subset of the plurality of spaced-apart existing perforations, and into the subterranean formation. This may include injecting through the initial subset of the plurality of spaced-apart existing perforations while, at the same time, resisting, blocking, and/or occluding flow of the stimulant fluid past the initial isolation device and/or to, into, and/or through stimulation zones that are downhole from the initial stimulation zone.

As another example, the stimulating at 225 may include injecting a fracturing fluid into the initial region of the subterranean formation to fracture the initial region of the subterranean formation. As yet another example, the stimulating at 225 may include injecting a proppant, or a proppant slurry, into the initial region of the subterranean formation to prop one or more fractures that may extend within the initial region of the subterranean formation. As another example, the stimulating at 225 may include injecting an acid into the initial region of the subterranean formation to dissolve at least a portion of the initial region of the subterranean formation. As yet another example, the stimulating at 225 may include bullheading the stimulant fluid into the tubular conduit from the surface region. This may include flowing the stimulant fluid, in fluid contact with the downhole tubular, between the surface region and the initial stimulation zone.

It is within the scope of the present disclosure that the stimulating at 225 may include stimulating an entirety of the initial region of the subterranean formation and/or flowing the stimulant fluid through each of the initial subset of the plurality of existing perforations during an entirety of a duration of the stimulating at 225. This is illustrated in FIGS. 8-10 by stimulated regions 38. Stimulated regions 38 are formed within initial region 32 of the subterranean formation via flow of stimulant fluid 120 into the subterranean formation.

Alternatively, it also is within the scope of the present disclosure that the stimulating at 225 may include stimulating in one or more steps, or stages. As an example, the stimulating at 225 may include injecting the stimulant fluid into the subterranean formation via the initial subset of the plurality of spaced-apart existing perforations for a first stimulation time period and subsequently sealing a most fluid-receptive fraction of the initial subset of the plurality of spaced-apart existing perforations. Subsequently, the stimulating at 225 may include injecting the stimulant fluid into the subterranean formation via a remainder of the initial subset of the plurality of spaced-apart existing perforations for a second stimulation time period.

As another example, and when methods 200 include the adding at 210, the initial stimulation zone may include a plurality of initial perforations that includes both the initial subset of the plurality of spaced-apart existing perforations and an initial subset of the plurality of spaced-apart new perforations. Under these conditions, the stimulating at 225 may include injecting the stimulant fluid into the subterranean formation via both the initial subset of the plurality of spaced-apart existing perforations and the initial subset of the plurality of spaced-apart new perforations for the first stimulation time period. The stimulating at 225 then may include sealing a most fluid-receptive fraction of the plurality of initial perforations and subsequently injecting the stimulant fluid into the subterranean formation via a remainder of the plurality of initial perforations for a second stimulation time period.

This multi-step stimulation is illustrated in FIGS. 20-22, which illustrate a downhole tubular 60, which defines a tubular conduit 62, extending within a subterranean formation 30. Downhole tubular 60 may include a plurality of existing perforations 70 and/or a plurality of new perforations 80, which collectively may be referred to herein as perforations 138.

As illustrated in FIG. 20, a majority of stimulant fluid 120, which is supplied to subterranean formation 30 via tubular conduit 62, initially may flow into the subterranean formation via a most fluid-receptive fraction 140 of perforations 138. Subsequently, and as illustrated in FIG. 21, most fluid-receptive fraction 140 of perforations 138 may be sealed, such as utilizing sealing devices 130. This sealing of most fluid-receptive fraction 140 may focus, or direct, flow of stimulant fluid 120 into the subterranean formation via a remainder of perforations 138 (e.g., an unsealed fraction of perforations 138), as illustrated in FIG. 21, thereby improving stimulation of region(s) of subterranean 30 that are not in direct fluid communication with most fluid-receptive fraction 140. This multi-step stimulation process may be repeated any suitable number of times until regions of the subterranean formation associated with all perforations 138 have been satisfactorily stimulated and/or until all perforations 138 have been sealed by corresponding sealing devices 130, as illustrated in FIG. 22.

Sealing the initial subset of the plurality of perforations at 230 may include sealing each perforation in the initial subset of the plurality of spaced-apart existing perforations and/or sealing each perforation in the plurality of spaced-apart new perforations with a corresponding initial sealing device. This may include flowing a plurality of initial sealing devices, via the tubular conduit and/or within the stimulant fluid, into contact with corresponding perforations in the initial subset of the plurality of perforations.

It is within the scope of the present disclosure that the sealing at 230 may include concurrently, or at least substantially concurrently, sealing each and/or every perforation in the initial subset of the plurality of perforations. Alternatively, it also is within the scope of the present disclosure that the sealing at 230 may include sealing the plurality of perforations in a plurality of steps, or stages, as discussed herein with reference to the stimulating at 225.

The sealing at 230 is illustrated in FIGS. 8-10 and 20-22. As illustrated therein, and subsequent to stimulation of the subterranean formation with stimulant fluid 120 to form a plurality of stimulated regions 38 therein, sealing devices 130 may be utilized to seal the plurality of spaced-apart existing perforations 70, thereby restricting fluid flow from the tubular conduit and into the subterranean formation via the plurality of existing perforations. This may permit pressurization of initial stimulation zone 112 with stimulant fluid 120.

Establishing fluid communication between the initial stimulation zone and the adjacent stimulation zone at 235 may include establishing the fluid communication while maintaining the sealing at 230. Stated another way, the establishing at 235 may include establishing fluid communication between the initial stimulation zone and the adjacent stimulation zone while, at the same time, restricting fluid flow between the tubular conduit and the subterranean formation via the initial subset of the plurality of perforations. The adjacent stimulation zone is downhole from the initial stimulation zone.

The establishing at 235 may include establishing the fluid communication in any suitable manner. As an example, and as illustrated in the transition from FIG. 8 to FIG. 11, the establishing at 235 may include removing initial isolation device 102 from isolation structure 90 that separates initial stimulation zone 112 from subsequent stimulation zone 114 and/or removing the isolation structure that includes the initial isolation device.

As another example, and when the positioning at 215 includes positioning the plurality of frangible isolation structures, the establishing at 235 may include breaking, shattering, and/or otherwise removing an initial frangible isolation structure that extends between, or fluidly separates, the initial stimulation zone and the adjacent stimulation zone. This is illustrated in the transition from FIG. 9 to FIG. 12, with initial frangible isolation device 102 being present in FIG. 9 and absent, or removed, from isolation structure 90 in FIG. 12.

When the isolation structure includes the frangible isolation structure, the establishing at 235 may include one or more of generating a shockwave within a wellbore fluid that extends within the tubular conduit to provide a motive force for shattering of the frangible isolation structure and/or pressurizing the wellbore fluid to greater than a threshold shattering pressure for the frangible isolation structure. Additionally or alternatively, the frangible isolation structure may be configured to shatter responsive to receipt of another suitable transition signal, and the establishing at 235 may include providing the transition signal to the frangible isolation structure. Additional examples of transition signals include a wired transition signal, a wireless transition signal, an electromagnetic transition signal, an acoustic transition signal, a pressure pulse of greater than a predetermined magnitude, a predetermined pressure pulse sequence, a predetermined acoustic signal, and/or a predetermined wireless signal.

As yet another example, and when methods 200 include the positioning at 220, the establishing at 235 may include shearing the initial isolation device seat and/or forcing the initial isolation device through the initial isolation device seat. This is illustrated in the transition from FIG. 10 to FIG. 13, with initial isolation ball 102 being present on isolation device seat 94 and thereby fluidly isolating initial stimulation zone 112 from adjacent stimulation zone 114 in FIG. 10 and the initial isolation ball being absent from the corresponding isolation device seat in FIG. 13. The shearing and/or forcing may be accomplished in any suitable manner. As an example, the shearing and/or forcing may include pressurizing the tubular conduit to greater than a threshold shearing and/or forcing pressure.

When methods 200 include the positioning at 220, methods 200 also, or subsequently, may include the positioning at 240. The positioning at 240 may be performed subsequent to the establishing at 235 and/or prior to the stimulating at 245.

The positioning at 240, when performed, may include positioning the adjacent isolation device on an adjacent isolation device seat to hydraulically isolate the adjacent stimulation zone from stimulation zones that are downhole from the adjacent stimulation zone. The positioning at 240 may be similar, or at least substantially similar, to the positioning at 220, which is discussed in more detail herein.

It is within the scope of the present disclosure that the adjacent isolation device may be different from the initial isolation device and/or may be distinct from the initial stimulation device. Under these conditions, the isolation device seats may progressively differ, or increase, in size from a most uphole isolation device seat to a most downhole isolation device seat; and the positioning at 240 may include flowing the adjacent isolation device, such as from the surface region, into contact with the adjacent isolation device seat.

Alternatively, it also is within the scope of the present disclosure that the adjacent isolation device includes, or is, the initial isolation device. Under these conditions, each isolation device seat may be the same, or at least substantially the same, size as each other isolation device seat; and the positioning at 240 may include flowing the initial isolation device from the initial stimulation device seat to and/or into contact with the adjacent isolation device seat.

The positioning at 240 is illustrated in FIG. 13. As illustrated therein, adjacent isolation device 104, in the form of an adjacent isolation ball 104, is positioned upon isolation device seat 94 that extends between adjacent stimulation zone 114 and subsequent stimulation zone 116.

Stimulating the adjacent region of the subterranean formation at 245 may include stimulating any suitable adjacent region of the subterranean formation that is associated with the adjacent stimulation zone. The stimulating at 245 may be similar, or at least substantially similar, to the stimulating at 225. The adjacent stimulation zone may include an adjacent subset of the plurality of perforations, and the stimulating at 245 may include injecting the stimulant fluid from the surface region, via the tubular conduit, through the initial stimulation zone, through the adjacent subset of the plurality of spaced-apart perforations, and into the subterranean formation. The stimulating at 245 further may include resisting flow of the stimulant fluid through stimulation zones of the plurality of stimulation zones that are downhole from the adjacent stimulation zone. Methods 200 also may include resisting flow of the stimulant fluid through the initial subset of the plurality of perforations during the stimulating at 245. As such, methods 200 focus flow of the stimulant fluid through the adjacent subset of the plurality of perforations, thereby providing improved, focused, and/or directed stimulation of the adjacent region of the subterranean formation.

The stimulating at 245 is illustrated by the transition from FIGS. 11-13 to FIGS. 14-17. As illustrated in FIGS. 11-13, and prior to the stimulating at 245, stimulated regions 38 extend within initial region 32 but not within adjacent region 34 of the subterranean formation. However, and subsequent to the stimulating at 245, stimulated regions 38 extend in both initial region 32 and adjacent region 34.

It is within the scope of the present disclosure that methods 200 may include stimulating, or sequentially stimulating, any suitable number of different, distinct, and/or spaced-apart regions of the subterranean formation. This generally will include progressing in a downhole direction, with each stimulated region being downhole from previously stimulated regions of the subterranean formation.

As an example, and subsequent to the stimulating at 245, methods 200 further may include sealing the adjacent subset of the plurality of perforations at 250. The sealing at 250 may be similar, or at least substantially similar, to the sealing at 230, which is discussed herein.

Subsequently, methods 200 may include establishing fluid communication between the adjacent stimulation zone and the subsequent stimulation zone at 255. As discussed, the subsequent stimulation zone may be downhole from the adjacent stimulation zone, and the establishing at 255 may include establishing the fluid communication while maintaining the sealing at 230 and also while maintaining the sealing at 250. The establishing at 255 may be similar, or at least substantially similar, to the establishing at 235.

Subsequently, methods 200 may include stimulating a subsequent region of the subterranean formation at 260, which is associated with the subsequent stimulation zone. This may include flowing the stimulant fluid from the surface region, via the tubular conduit, through the initial stimulation zone, through the adjacent stimulation zone, and through a subsequent subset of the plurality of perforations, which is associated with the subsequent stimulation zone. The stimulating at 260 further may include flowing the stimulant fluid into the subterranean formation via the subsequent subset of the plurality of perforations while resisting flow of the stimulant fluid through stimulation zones that are downhole from the subsequent stimulation zone.

This is illustrated in FIGS. 17-18, with initial stimulation zone 112, adjacent stimulation zone 114, and subsequent stimulation zone 116 all including stimulated regions 38 extending therein. Initial stimulation zone 112 includes an initial subset 72 of the plurality of spaced-apart existing perforations 70, which is sealed by initial sealing devices 132. Adjacent stimulation zone 114 includes an adjacent subset 74 of the plurality of spaced-apart existing perforations 70, which is sealed by adjacent sealing devices 134, and subsequent stimulation zone 116 includes a subsequent subset 76 of the plurality of spaced-apart existing perforations 70, which is sealed by subsequent sealing devices 136.

Subsequent to stimulation of a desired number of regions of the subterranean formation via corresponding stimulation zones, methods 200 further may include clearing the tubular conduit at 265. This may include clearing, or cleaning, the tubular conduit to permit and/or facilitate subsequent production from the subterranean formation via the tubular conduit.

The clearing at 265 may include clearing in any suitable manner. As examples, the clearing at 265 may include removing at least a subset of the plurality of isolation structures from the tubular conduit, removing at least a subset of the plurality of isolation devices from the tubular conduit, and/or removing at least a subset of the plurality of sealing devices from the tubular conduit.

As additional examples, the clearing at 265 may include running a mill through the tubular conduit, such as to mill away the plurality of isolation structures, the plurality of isolation devices, and/or the plurality of sealing devices, and/or providing an acid to the tubular conduit, such as to corrode and/or dissolve the plurality of isolation structures, the plurality of isolation devices, and/or the plurality of sealing devices. This is illustrated in FIG. 19, with tubular conduit 62 being free of isolation structures, isolation devices, and/or sealing devices.

In the present disclosure, several structures, subsets, and/or regions are described with the adjectives “initial,” “adjacent,” and “subsequent.” In general, “initial” structures, subsets, and/or regions will be utilized, during methods 200, prior to “adjacent” structures, subsets, and/or regions, which will be utilized, during methods 200, prior to “subsequent” structures, subsets, and/or regions. Thus, and while indicative of timing, sequencing, and/or chronology, the adjectives “initial,” “adjacent,” and “subsequent” are not intended to convey, or to require, a specific spatial relationship, immediate adjacency, and/or an abutting arrangement among the various structures, subsets, and/or regions. With this in mind, the adjectives “initial,” “adjacent,” and “subsequent” may be replaced with the adjectives “first,” “second,” and “third” or “uphole,” “middle,” and “downhole,” respectively, without departing from the scope of the present disclosure.

In the present disclosure, several of the illustrative, non-exclusive examples have been discussed and/or presented in the context of flow diagrams, or flow charts, in which the methods are shown and described as a series of blocks, or steps. Unless specifically set forth in the accompanying description, it is within the scope of the present disclosure that the order of the blocks may vary from the illustrated order in the flow diagram, including with two or more of the blocks (or steps) occurring in a different order and/or concurrently.

As used herein, the term “and/or” placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entities listed with “and/or” should be construed in the same manner, i.e., “one or more” of the entities so conjoined. Other entities may optionally be present other than the entities specifically identified by the “and/or” clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” may refer, in one embodiment, to A only (optionally including entities other than B); in another embodiment, to B only (optionally including entities other than A); in yet another embodiment, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.

As used herein, the phrase “at least one,” in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entity in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase “at least one” refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” may mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B and C together, and optionally any of the above in combination with at least one other entity.

In the event that any patents, patent applications, or other references are incorporated by reference herein and (1) define a term in a manner that is inconsistent with and/or (2) are otherwise inconsistent with, either the non-incorporated portion of the present disclosure or any of the other incorporated references, the non-incorporated portion of the present disclosure shall control, and the term or incorporated disclosure therein shall only control with respect to the reference in which the term is defined and/or the incorporated disclosure was present originally.

As used herein the terms “adapted” and “configured” mean that the element, component, or other subject matter is designed and/or intended to perform a given function. Thus, the use of the terms “adapted” and “configured” should not be construed to mean that a given element, component, or other subject matter is simply “capable of” performing a given function but that the element, component, and/or other subject matter is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the function. It also is within the scope of the present disclosure that elements, components, and/or other recited subject matter that is recited as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa.

As used herein, the phrase, “for example,” the phrase, “as an example,” and/or simply the term “example,” when used with reference to one or more components, features, details, structures, embodiments, and/or methods according to the present disclosure, are intended to convey that the described component, feature, detail, structure, embodiment, and/or method is an illustrative, non-exclusive example of components, features, details, structures, embodiments, and/or methods according to the present disclosure. Thus, the described component, feature, detail, structure, embodiment, and/or method is not intended to be limiting, required, or exclusive/exhaustive; and other components, features, details, structures, embodiments, and/or methods, including structurally and/or functionally similar and/or equivalent components, features, details, structures, embodiments, and/or methods, are also within the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The systems, wells, and methods disclosed herein are applicable to the oil and gas, well drilling, well completion, and/or well re-completion industries.

It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Similarly, where the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.

It is believed that the following claims particularly point out certain combinations and subcombinations that are directed to one of the disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower, or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.

Claims

1. A method for refracturing a subterranean formation via a hydrocarbon well including a downhole tubular extending within a wellbore formed within the subterranean formation, the method comprising:

positioning a plurality of isolation structures within a tubular conduit defined by the downhole tubular to define a plurality of spaced-apart stimulation zones within the tubular conduit, wherein the downhole tubular includes a plurality of spaced-apart existing perforations that provides fluid communication between the tubular conduit and the subterranean formation, and further wherein each stimulation zone of the plurality of spaced-apart stimulation zones includes a corresponding subset of the plurality of spaced-apart existing perforations;

subsequent to the positioning, stimulating an initial region of the subterranean formation associated with an initial stimulation zone of the plurality of spaced-apart stimulation zones, wherein the initial stimulation zone includes an initial subset of the plurality of spaced-apart existing perforations, wherein the stimulating the initial region includes injecting a stimulant fluid from a surface region, via the tubular conduit, through the initial subset of the plurality of spaced-apart existing perforations, and into the subterranean formation while resisting flow of the stimulant fluid through stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the initial stimulation zone;

sealing the initial subset of the plurality of spaced-apart existing perforations;

establishing fluid communication between the initial stimulation zone and an adjacent stimulation zone of the plurality of spaced-apart stimulation zones within the tubular conduit while maintaining the sealing the initial subset of the plurality of spaced-apart existing perforations, wherein the adjacent stimulation zone is downhole from the initial stimulation zone; and

stimulating an adjacent region of the subterranean formation associated with the adjacent stimulation zone, wherein the adjacent stimulation zone includes an adjacent subset of the plurality of spaced-apart existing perforations, wherein the stimulating the adjacent region includes injecting the stimulant fluid from the surface region, via the tubular conduit, through the initial stimulation zone, through the adjacent subset of the plurality of spaced-apart existing perforations, and into the subterranean formation while resisting flow of the stimulant fluid through stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the adjacent stimulation zone.

2. The method of claim 1, wherein the positioning includes sequentially positioning the plurality of isolation structures within the tubular conduit to define the plurality of spaced-apart stimulation zones, wherein the sequentially positioning includes positioning such that each isolation structure of the plurality of isolation structures is uphole from previously positioned isolation structures of the plurality of isolation structures.

3. The method of claim 1, wherein the positioning includes positioning a plurality of frangible isolation structures, wherein each frangible isolation structure of the plurality of frangible isolation structures resists fluid flow from an uphole region of the tubular conduit, which is uphole therefrom, to a downhole region of the tubular conduit, which is downhole therefrom.

4. The method of claim 3, wherein the positioning includes positioning an initial frangible isolation structure of the plurality of frangible isolation structures, which hydraulically isolates the initial stimulation zone from the adjacent stimulation zone, and further wherein the establishing includes shattering the initial frangible isolation structure.

5. The method of claim 4, wherein the shattering includes at least one of:

(i) generating a shockwave within a wellbore fluid, which extends within the tubular conduit, to provide a motive force for the shattering;

(ii) providing a transition signal to the initial frangible isolation structure, wherein the initial frangible isolation structure is configured to shatter responsive to receipt of the transition signal; and

(iii) pressurizing the wellbore fluid to greater than a threshold shattering pressure.

6. The method of claim 5, wherein the transition signal includes at least one of:

(i) a pressure pulse of a predetermined magnitude;

(ii) a predetermined pressure pulse sequence;

(iii) a predetermined acoustic signal; and

(iv) a predetermined wireless signal.

7. The method of claim 1, wherein the positioning includes positioning a plurality of isolation device seats within the tubular conduit, wherein each isolation device seat, when combined with a corresponding isolation device, resists fluid flow from an uphole region of the tubular conduit, which is uphole therefrom, to a downhole region of the tubular conduit, which is downhole therefrom.

8. The method of claim 7, wherein, subsequent to the positioning and prior to the stimulating the initial region, the method further includes positioning an initial isolation device on an initial isolation device seat to hydraulically isolate the initial stimulation zone from the stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the initial stimulation zone.

9. The method of claim 8, wherein the positioning includes flowing the initial isolation device into contact with the initial isolation device seat.

10. The method of claim 8, wherein the tubular conduit provides fluid communication among the stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the initial stimulation zone.

11. The method of claim 8, wherein the establishing includes at least one of:

(i) shearing the initial isolation device seat; and

(ii) forcing the initial isolation device through the initial isolation device seat.

12. The method of claim 8, wherein, subsequent to the establishing and prior to the stimulating the adjacent region of the subterranean formation, the method further includes positioning an adjacent isolation device on an adjacent isolation device seat to hydraulically isolate the adjacent stimulation zone from stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the adjacent stimulation zone.

13. The method of claim 1, wherein the stimulating the initial region of the subterranean formation includes at least one of:

(i) injecting a fracturing fluid into the initial region of the subterranean formation to fracture the initial region of the subterranean formation;

(ii) injecting a proppant into the initial region of the subterranean formation to prop one or more fractures that extend within the initial region of the subterranean formation;

(iii) injecting an acid into the initial region of the subterranean formation to dissolve at least a portion of the initial region of the subterranean formation; and

(iv) bullheading the stimulant fluid into the tubular conduit from the surface region.

14. The method of claim 1, wherein the stimulating the adjacent region of the subterranean formation includes at least one of:

(i) injecting a fracturing fluid into the adjacent region of the subterranean formation to fracture the adjacent region of the subterranean formation;

(ii) injecting a proppant into the adjacent region of the subterranean formation to prop one or more fractures that extend within the adjacent region of the subterranean formation;

(iii) injecting an acid into the adjacent region of the subterranean formation to dissolve at least a portion of the adjacent region of the subterranean formation; and

(iv) bullheading the stimulant fluid into the tubular conduit from the surface region.

15. The method of claim 1, wherein the sealing the initial subset of the plurality of spaced-apart existing perforations includes sealing with a plurality of initial sealing devices.

16. The method of claim 1, wherein, subsequent to the stimulating the adjacent region of the subterranean formation, the method further includes:

sealing the adjacent subset of the plurality of spaced-apart existing perforations;

establishing fluid communication between the adjacent stimulation zone and a subsequent stimulation zone of the plurality of spaced-apart stimulation zones, which is downhole from the adjacent stimulation zone, while maintaining the sealing the initial subset of the plurality of spaced-apart existing perforations and also maintaining the sealing the adjacent subset of the plurality of spaced-apart existing perforations; and

stimulating a subsequent region of the subterranean formation associated with the subsequent stimulation zone, wherein the stimulating the subsequent region includes flowing the stimulant fluid from the surface region, via the tubular conduit, through the initial stimulation zone, through the adjacent stimulation zone, through a subsequent subset of the plurality of spaced-apart existing perforations, which is associated with the subsequent stimulation zone, and into the subterranean formation while resisting flow of the stimulant fluid through stimulation zones of the plurality of spaced-apart stimulation zones that are downhole from the subsequent stimulation zone.

17. The method of claim 1, wherein the method includes sequentially stimulating a region of the subterranean formation associated with each stimulation zone of the plurality of spaced-apart stimulation zones, wherein each subsequently stimulated region of the subterranean formation is downhole from a previously stimulated stimulation zone.

18. The method of claim 1, wherein, prior to the stimulating the initial region of the subterranean formation, the method further includes adding new perforations to the downhole tubular, wherein the adding new perforations to the downhole tubular includes generating a plurality of spaced-apart new perforations within the downhole tubular.

19. The method of claim 17, wherein the initial stimulation zone includes a plurality of initial perforations, which includes both the initial subset of the plurality of spaced-apart existing perforations and an initial subset of the plurality of spaced-apart new perforations, and further wherein the stimulating the initial region of the subterranean formation further includes:

(i) injecting the stimulant fluid into the subterranean formation via both the initial subset of the plurality of spaced-apart existing perforations and the initial subset of the plurality of spaced-apart new perforations for a first stimulation time period;

(ii) sealing a most fluid-receptive fraction of the plurality of initial perforations; and

(iii) injecting the stimulant fluid into the subterranean formation via a remainder of the plurality of initial perforations for a second stimulation time period.

20. The method of claim 1, wherein the stimulating the initial region of the subterranean formation includes:

(i) injecting the stimulant fluid into the subterranean formation via the initial subset of the plurality of spaced-apart existing perforations for a first stimulation time period;

(ii) sealing a most fluid-receptive fraction of the initial subset of the plurality of spaced-apart existing perforations; and

(iii) injecting the stimulant fluid into the subterranean formation via a remainder of the initial subset of the plurality of spaced-apart existing perforations for a second stimulation time period.

21. The method of claim 1, wherein the sealing comprises using at least one of:

(i) a plurality of ball sealers;

(ii) a plurality of conformable sealers;

(iii) a plurality of beads;

(iv) a plurality of poly lactic acid beads;

(v) a plurality of fibers;

(vi) a plurality of poly lactic acid fibers;

(vii) a plurality of rods;

(viii) a plurality of poly lactic acid rods; and

(ix) combinations thereof.

22. The method of claim 1, wherein, prior to the positioning the initial stimulation device, the method further includes cleanout of the tubular conduit.

23. The method of claim 22, wherein the cleanout includes flushing solids from the tubular conduit.

24. The method of claim 22, wherein the cleanout includes utilizing coiled tubing.

25. The method of claim 1, wherein, subsequent to stimulation of a desired number of regions of the subterranean formation via corresponding stimulation zones of the plurality of spaced-apart stimulation zones, the method further includes cleanout the tubular conduit.

26. The method of claim 25, wherein the cleanout includes at least one of:

(i) removing the plurality of isolation structures from the tubular conduit;

(ii) removing a plurality of isolation devices from the tubular conduit; and

(iii) removing a plurality of sealing devices from the tubular conduit.

27. The method of claim 25, wherein the cleanout includes at least one of:

(i) running a mill through the tubular conduit; and

(ii) providing an acid to the tubular conduit.