Abstract: Methods for the treatment of subterranean wells involving injecting a first fracturing fluid into a formation, and then injecting at least a second fracturing fluid into the formation in order to create extended conductive channels through a formation are described. The fracturing fluids can be similar in density, viscosity, pH and the other related characteristics. Alternatively, the fracturing fluids can differ in their densities, viscosities, and pH, allowing for variations in the conductive channels formed. Propping agents can also be included in one or both of the injected fluids, further enhancing the conductive channels formed. The described methods aid in minimizing proppant flowback problems typically associated with hydraulic fracturing techniques.

Abstract: A downhole service tool is provided that may include a body having an interior passageway, at least one exit port through which fluid may flow from the interior passageway to an exterior of the tool, and at least one diverting channel adapted to cause fluid exiting the exit port to flow in a predetermined pattern, such as a helical or rotational flow path. The diverting channel may be in the form of a trough, and may also have a tapering width from its upper end to its lower end, where it meets the exterior of the tool. The diverting channel may also have a helical or other predetermined shape so as to facilitate the inducement of the desired flow pattern. By designing the tool so as to create a desired flow pattern, erosion of the tool by the exiting fluid flow is lessened. Related methods are also provided.

Abstract: A system for completing a well having casing (34) includes a perforating assembly (38) and a tubing string assembly (40). The tubing string assembly (40) including a pair of seal assemblies (56, 74), a production screen assembly (58) and a ported sleeve (66) positioned between the seal assemblies (56, 74) and a live annulus screen assembly (76) positioned uphole of the seal assemblies (56, 74). The perforating assembly (38) is operated to perforate the well and is then released downhole. The tubing string assembly (40) is then repositioned such that the production screen assembly (58) is located proximate the perforated interval (14) so that when the well is hydraulically fractured with a treatment slurry that is pumped through the ported sleeve (66), the formation reaction to the fracturing is monitored by obtaining pressure readings in the annulus in fluid communication with the live annulus screen assembly (76).

Abstract: Methods and apparatus for fracturing a subterranean formation which use a fracturing tool. The fracturing tool includes a hydrajet tool, with at least one fluid jet and at least one fracturing port extending through the liner. The fracturing tool further includes a rotating sleeve with at least one interior fracturing port and at least one interior fluid jet port. Finally, the fracturing tool may include a power unit capable of changing the orientation of the rotating sleeve. During fracturing operations, fracturing fluid is pressured through the fluid jet to form microfractures. The orientation of the rotating sleeve may then be changed and fluid may be forced through the fracturing ports to form fractures by the stagnation pressure of the fracturing fluid.

Abstract: The present invention provides a method for gravel packing a open-hole wellbore having a filter cake, comprising pumping a gravel slurry into a first portion of an annulus between the wellbore and a screen, at a sufficient rate and pressure to form at least a first fracture and diverting the gravel slurry to a second portion of said annulus through alternate flowpaths while providing hydraulic isolation between the first and the second portion of said interval, thereby preventing flowback from said second portion to said first portion and resulting extension of the first fracture, and thereby forming a second fracture in said second portion of said interval.

Abstract: Method and apparatus for fracturing different levels of a completion interval in a well. A workstring lowers a fracturing string which, in turn, is comprised of a base pipe which is blank except for perforated sections spaced along its length. Screen may be provided over said sections to block the flow of sand into the base pipe. An alternate flow path (e.g. shunt tubes) extends along the base pipe and has one or more outlets spaced along its length. A slurry is flowed into the annulus surrounding the fracturing string. As liquid is lost from the slurry, sand from the slurry will form bridges at said perforated sections thereby isolating portions of the annulus. Slurry then flows through the shunts tube(s) and out into the isolated portions to fracture the different levels in the completion interval.

Abstract: The present invention relates to a method and system for hydrating a gel for treating a wellbore penetrating a subterranean formation. The method includes directing a base fluid through an inlet into a mixer having an inner chamber housing a plurality of impellors extending radially from and rotating about a hub, causing a centrifugal motion of the base fluid, feeding a quantity of gel into the mixer, mixing the gel with the base fluid and discharging the now-hydrated gel from the inner chamber through an outlet of the mixer. A prewetting device may also be used. Thereafter, a variety of additives may be added to the gel fluid mix to form a fluid treatment to be introduced into a subterranean formation.

Abstract: A method and apparatus is provided for created multiple fractures in a subterranean formation with a single, continuous treatment operation. A plurality of burst disk assemblies are included, each having an independent burst pressure and corresponding to a specific interval to be treated, whereby the assemblies are arranged on a work or completion string such that the assembly with the lowest burst pressure is positioned at the toe, or lowest position, and subsequent assemblies have increasing burst pressures toward the heel of the string. As fluid is pumped down the string, pressure builds up to exceed the burst pressure of the first disk, allowing treatment fluid to contact the formation. Once a first interval treated or fractured, it may be isolated thereby allowing pressure to again build up in the string and burst subseqent disks.

Abstract: According to one embodiment of the invention, a flow conditioning system for fluid jetting tools includes a housing having a plurality of jet nozzle openings and a fluid straightener disposed within the housing. The fluid straightener is defined by one or more vanes, and the vanes form a plurality of flow channels within the housing. Each flow channel is associated with at least one jet nozzle opening.

Abstract: A system for fracturing wells uses a primary propellant charge to initially produce pressures within the well in excess of the maximum fracture extension pressure of the surrounding formation, but below that which would cause damage to the well. A supplemental propellant charge burns for a substantially longer period of time than the primary propellant charge, and thereby maintains pressures within the well in excess of the maximum fracture extension pressure for a significant period of time following completion of the primary propellant burn.

Abstract: A service/completion liner having a plurality of downhole selectable indicating tools and being used in sand control (gravel pack) placement systems in conjunction with a straddle packer service tools or with conventional crossover type service tools. Each indicating collar has a downhole selectable indicating collar providing a robust, landing profile for precisely locating and maintaining service tool position during well treatment operations. The landing collars accommodate hydraulic and/or thermal effects commonly referred to as tubing move effects which are the principle cause of tool position error and excessive seal wear. The landing collar is downhole convertible between a pass through (Go) and non pass through (No-go) condition by simple upward and downward cycling via the tool running and treatment fluid tubing and a shifting tool, which may also be referred to as a set down collet.

Abstract: The invention discloses methods of, as well as apparatus and systems for, perforating and treating multiple intervals of one or more subterranean formations intersected by a wellbore by deploying within said wellbore a bottom-hole assembly (“BHA”) having a perforating device and a sealing mechanism, wherein pressure communication is established between the portions of the wellbore above and below the sealing mechanism. The BHA is positioned within the wellbore such that the sealing mechanism, when actuated, establishes a hydraulic seal in the wellbore to positively force fluid to enter the perforations corresponding to the interval to be treated. A treating fluid is pumped down the wellbore and into the perforations created in the perforated interval. The sealing mechanism is released, and the steps are repeated for as many intervals as desired, without having to remove the BHA from said wellbore.

Abstract: The invention discloses methods of, as well as apparatus and systems for, perforating and treating multiple intervals of one or more subterranean formations intersected by a wellbore by deploying within said wellbore a bottom-hole assembly (“BHA”) having a perforating device and a sealing mechanisms, wherein pressure communication is established between the portions of the wellbore above and below the sealing mechanism. The BHA is positioned within the wellbore such that the sealing mechanism, when actuated, establishes a hydraulic seal in the wellbore to positively force fluid to enter the perforations corresponding to the interval to be treated. A treating fluid is pumped down the wellbore and into the perforations created in the perforated interval. The sealing mechanism is released, and the steps are repeated for as many intervals as desired, without having to remove the BHA from said wellbore.

Abstract: A cementing manifold is disclosed that preferably includes: modular housings that can be stacked together and interconnected to add multi-dart or multi-sphere capability; identical, interchangeable valves; internal bypass capability; a minimum number of protrusions into the pressure containing components; and no externally mounted welded or threaded components. A cementing swivel is also disclosed that preferably includes connections that are formed integrally to the housing, redundant cement connections, angled cement ports, and seal assemblies that do not require individual placement of each seal.

Abstract: The present invention relates to straddle packer systems and methods of using them for downhole isolation of zones for fracturing treatment. More specifically, the system includes upper and lower seal systems having resiliently flexible sealing elements hydraulically and operatively connected to one another which are responsive to an increase in hydraulic pressure for setting the sealing elements at a first hydraulic pressure threshold. Additionally, the system includes a control system hydraulically and operatively connected between the upper and lower packer systems which is responsive to an increase in hydraulic pressure at a second hydraulic pressure threshold higher for activating a pressure switch system within the control system for opening at least one frac valve in the control system.

Abstract: The present invention relates to a method and system for hydrating a gel for treating a wellbore penetrating a subterranean formation. The method includes directing a base fluid through an inlet into a mixer having an inner chamber housing a plurality of impellors extending radially from and rotating about a hub, causing a centrifugal motion of the base fluid, feeding a quantity of gel into the mixer, mixing the gel with the base fluid and discharging the now-hydrated gel from the inner chamber through an outlet of the mixer. A prewetting device may also be used. Thereafter, a variety of additives may be added to the gel fluid mix to form a fluid treatment to be introduced into a subterranean formation.

Abstract: A bottom hole assembly for use with fracturing or fracing a wellbore using coiled tubing is described having a first packing element and a second packing on a mandrel. The bottom hole assembly may be run into the wellbore such that the packing elements straddle the zone to be fraced. Also described is a timing mechanism to prevent the closing of dump ports before the bottom hole assembly may be flushed of the sand. A release tool is described that allows an operator to apply force to the coiled tubing to dislodge a bottom hole assembly without completely releasing the bottom hole assembly. Also disclosed is a collar locator capable of being utilized in a fracing process. Methods of using the above described components are also disclosed.

Abstract: Changes occurring downhole during a fracturing process can create or reflect pressure signals. Capturing and evaluating such pressure waves during fracturing enables personnel to monitor, in real time or later, what happens downhole. When a fracture extends, a burst of acoustic noise is embodied in a pressure wave or signal, as is noise coming from other sources. By transforming time-based pressure signals to a frequency base, one can monitor this acoustic noise. In a particular implementation, a waterfall plot of frequency spectra at successive time slices of the original signal is used to determine frequency ridges, such as a ridge of decreasing frequencies indicates fracture extension and a ridge of increasing frequencies indicates either closure or proppant backing up in the fracture. Filtering, such as wavelet filtering, can be used. A fracturing process can be controlled in response to determining whether the fracture is extending.

Abstract: A multi-zone packing system having unique features that allow for remote operation, thereby eliminating the need to raise and lower a work string and crossover tool to various zones of interest during a frac pack, gravel pack or related completion procedure. The squeeze pack system has a crossover tool or port collocated with each zone of interest and remotely operated closing devices to allow for the setting of each packer and the packing job to be performed with minimal or no movement of the work string.

Abstract: A tubing conveyed multi-position well treating tool having a tubular housing and a tubular inner member which are relatively positionable at “Set”, “Treat”, “Dump” and “Release” positions actuated by a mechanical indexing mechanism. The indexing mechanism is loaded by a spring, such as a compressed gas spring or mechanical spring, which urges the tubular housing away from the tubing connection of the inner tubular member, thus requiring no set-down forces for tool actuation or indexing. The treating tool is anchored within the well casing by hydraulic pressure actuated buttons, thus eliminating the typical requirement for anchoring actuation by set-down forces. The treating tool is sealed within the casing by pressure energized packers which are activated by the hydraulic pressure of fluid supplied from the tubing. The tool provides a bypass passage to allow communication of the zones above and below the tool while isolating the straddled interval to be treated.

Abstract: Screen assemblies (40, 42) and a single trip method for selectively fracturing multiple formations (14, 16) traversed by a wellbore (32) are disclosed. Each formation (14, 16) has a screen assembly (40, 42) having a plurality of valves (60, 66) positioned adjacent thereto. During the treatment process, the formations (14, 16) are selectively treated with a treatment fluid that is pumped into the interior of the adjacent screen assembly (40, 42). The valves (60, 66) of the respective screen assemblies (40, 42) progressively allow the treatment fluid to exit from the interior to the exterior of the screen assemblies (40, 42) such that each formation (14, 16) is progressively fractured.

Abstract: A technique for stimulating production of fluids from a subterranean formation. The technique utilizes a tubular member disposed within a wellbore. The tubular member comprises transverse openings that facilitate a formation fracturing process. Subsequent to fracturing, a completion element may be deployed within the tubular element. In some applications, the completion element is an expandable element.

Abstract: Method and apparatus for fracturing different levels of a completion interval in a well. A workstring lowers a fracturing string which, in turn, is comprised of a base pipe which is blank except for perforated sections spaced along its length. Screen may be provided over said sections to block the flow of sand into the base pipe. An alternate flow path (e.g. shunt tubes) extends along the base pipe and has one or more outlets spaced along its length. A slurry is flowed into the annulus surrounding the fracturing string. As liquid is lost from the slurry, sand from the slurry will form bridges at said perforated sections thereby isolating portions of the annulus. Slurry then flows through the shunts tube(s) and out into the isolated portions to fracture the different levels in the completion interval.

Abstract: An apparatus and method is provided for locating joints in coiled tubing operations. The apparatus is adapted for running into a well on coiled tubing and for use during reverse circulating and fracturing operations. The apparatus having a central passageway for fluids, a collar locator module, a one-way valve coupled to the central passageway to allow for the flow of fluids in one direction but not the other, a port coupled to the central passageway to allow fluids to exit when the one-way valve is functioning, a movable cover module to cover the port to build up pressure in the central passageway, and a flow diverting module for permanently diverting the flow of fluids from the port to the central passageway.

Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.

Abstract: A tool string, such as one used for performing fracturing operations or other types of operations, includes a valve, a valve operator, and a sealing assembly that in one arrangement includes packers to define a sealed zone. The tool string is carried on a tubing, through which fluid flow may be pumped to the sealed zone. The valve operator is actuated in response to fluid flow above a predetermined flow rate. When the flow rate at greater than the predetermined flow rate does not exist, the valve operator remains in a first position that corresponds to the valve being open. However, in response to a fluid flow rate at greater than the predetermined flow rate, the valve operator is actuated to a second position to close the valve.

Abstract: The invention discloses methods of, as well as apparatus and systems for, perforating and treating multiple intervals of one or more subterranean formations intersected by a wellbore by deploying a bottom-hole assembly (“BHA”) having a perforating device and a sealing mechanism within said wellbore. In one embodiment, the perforating device has no washing fluid flow passage provided therethrough. In another embodiment, an erosive jet device is used to perforate at least one interval of said one or more subterranean formations. In yet another embodiment, the BHA has at least one pressure equalization means that establishes pressure communication between the portions of the wellbore above and below the sealing mechanism. In another embodiment, the BHA comprises a perforating device and a sealing mechanism, wherein the perforating device is positioned below the sealing mechanism.

Abstract: The remediation treatment creates environmentally neutral species from hydrocarbon contaminants. For soils having a low porosity, fissures are created in the site by, for example, fluid, i.e., hydraulic or pneumatic, fracturing. A catalyst is injected into the site and is permitted to diffuse through the site. An oxidizing agent is then introduced into the site to release a free radical in a Fenton-type reaction. The compounds react to release a free radical, which acts upon the contaminants to form environmentally neutral species. Diffusion of both compounds is aided by turbulence induced in the groundwater. A pH-adjusting compound is added to optimize reaction conditions. Reaction vapors are collected above ground, filtered, and vented to the atmosphere, reducing the chance for gas pressure buildup and possibly dangerous, potentially explosive conditions.

Abstract: A perforating gun assembly for use in perforating multiple intervals of at least one subterranean formation intersected by a cased wellbore and in treating the multiple intervals using a diversion agent, such as ball sealers. In one embodiment, the apparatus of the present invention comprises a perforating assembly having a plurality of select-fire perforating devices interconnected by connector subs, with each of the perforating devices having multiple perforating charges. The apparatus also includes at least one decentralizer, attached to at least one of the perforating devices, which is adapted to eccentrically position the perforating assembly within the cased wellbore so as to create sufficient ball sealer clearance between the perforating assembly and the inner wall of the cased wellbore to permit passage of at least one ball sealer.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscoelastic surfactant fluid containing wormlike micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing methods useful for increasing hydrocarbon production, limiting connate water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of micelles of surfactant in aqueous zones of the subterranean formation facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: A wellbore (10) in an earth formation (12) having a casing (14) and a plurality of pay or production zones (32, 34, 36) provided in the formation. A coiled tubing string (18) from a reel (20) is injected by an injector (24) into the wellbore (10) for first perforating casing section (38) at each pay zone (32, 34, 36) in a single pass of the coiled tubing (18) as shown in FIG. 1. Next, the coiled tubing (18) is utilized for hydraulic fracturing each of the pay zones (32, 34, 36) individually from the lowermost pay zone (32) to the uppermost pay zone (36) in a single pass of the coiled tubing (18). Each pay zone (32, 34, 36) is isolated for the hydraulic fracturing. An upper packer (44 or 54) is provided above each of the pay zones for isolation and a lower packer (56) or sand plug (50) is utilized for isolating the lower or outermost end of each pay zone (32, 34, 36). Swab cups (58, 54A, 56A, 54B, 56B) are also utilized for isolation of pay zones.

Abstract: The invention provides an apparatus and method for perforating and treating multiple intervals of one or more subterranean formations intersected by a wellbore by deploying a bottom-hole assembly (“BHA”) having a perforating device and at least one sealing mechanism within said wellbore. The BHA may be deployed in the wellbore using a tubing string or cable; or alternatively, the BHA may be deployed using a tractor system attached directly to the BHA. The perforating device is used to perforate the first interval to be treated. Then the BHA is positioned within the wellbore such that the sealing mechanism, when actuated, establishes a hydraulic seal in the wellbore to positively force fluid to enter the perforations corresponding to the first interval to be treated. A treating fluid is then pumped down the wellbore and into the perforations created in the perforated interval.

Abstract: Breaking hard compact materials, such as rock and concrete, is based upon a controlled-fracturing process. A high-pressure foam is used to pressurize a predrilled hole of appropriate geometry. The high-pressure foam is delivered to the bottom of the drilled hole by a barrel inserted into the hole. The barrel includes a seal near the bottom of the hole. By restricting and controlling the pressure of the high-pressure foam to the bottom of the hole, a controlled fracturing is achieved which results in the fracturing and removing of a large volume of material at a low expenditure of energy. The foam-injection method produces almost no fly rock or airblast. The foam-injection method may be used to fracture, remove and/or excavate any hard material such as rock or concrete. The method may be used in either dry or water filled holes and the holes may be in any orientation. The foam injection apparatus is carried on a boom mounted on a carrier.

Abstract: A multi-zone screenless well fracturing method and apparatus which allows multiple zones in a well to be treated with one trip of the apparatus into the hole. The apparatus includes a tool string generally comprising a crossover, a packer below the crossover, and a concentric wash pipe extending below the packer. The crossover has a first portion in communication with a tubing string connected thereto and a second portion in communication with a well annulus above the packer. The first portion of the crossover is in communication with the inner wash pipe, and the second portion of the crossover is in communication with the outer wash pipe. The tool string is adapted to stab through a plurality of big bore casing packers which are positioned between adjacent zones. A method of fracturing multiple zones in a well while monitoring conditions at the zone is also disclosed.