Multiple Zone Completion System
A system and method for completing a well with multiple zones of production is provided. For example, a well completion system is provided including one or more polished bore receptacles installed in a casing and a fluid delivery device having at least one seal assembly for selectively isolating a selected well zone and delivering a fluid to the selected zone. Furthermore, a perforating gun may be connected to the fluid delivery device to facilitate perforating a target well zone, isolating the target well zone, and treating the target well zone in a single trip.
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Field of the Invention. The present invention relates generally to recovery of hydrocarbons in subterranean formations, and more particularly to a system and method for delivering treatment fluids to wells having multiple well zones.
Background of the Invention. In typical wellbore operations, various treatment fluids may be pumped into the well and eventually into the formation to restore or enhance the productivity of the well. For example, a non-reactive “fracturing fluid” or a “frac fluid” may be pumped into the wellbore to initiate and propagate fractures in the formation thus providing flow channels to facilitate movement of the hydrocarbons to the wellbore so that the hydrocarbons may be produced from the well. In such fracturing operations, the fracturing fluid is hydraulically injected into a wellbore penetrating the subterranean formation and is forced against the formation strata by pressure. The formation strata is forced to crack and fracture, and a proppant is placed in the fracture by movement of a viscous-fluid containing proppant into the crack in the rock. The resulting fracture, with proppant in place, provides improved flow of the recoverable fluid (i.e., oil, gas or water) into the wellbore. In another example, a reactive stimulation fluid or “acid” may be injected into the formation. Acidizing treatment of the formation results in dissolving materials in the pore spaces of the formation to enhance production flow.
Currently, in wells with multiple production zones, it may be necessary to treat various formations in a multi-staged operation requiring many trips downhole. Each trip generally consists of isolating a single production zone and then delivering the treatment fluid to the isolated zone. Since several trips downhole are required to isolate and treat each zone, the complete operation may be very time consuming and expensive.
Accordingly, there exists a need for systems and methods to deliver treatment fluids to multiple zones of a well in a single trip downhole.
SUMMARYThe present invention relates to a system and method for delivering a treatment fluid to a well having multiple well zones. According to some embodiments of the present invention, a well completion system is provided including one or more polished bore receptacles installed in a casing and a fluid delivery device having at least one seal assembly for selectively isolating a selected well zone and delivering a fluid to the selected zone.
Other or alternative embodiments of the present invention will be apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGSThe manner in which these objectives and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTIONIn the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
In the specification and appended claims: the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via another element”; and the term “set” is used to mean “one element” or “more than one element”. As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. Moreover, the term “sealing mechanism” includes: O-ring, chevron seal, V-packed seal, bonded elastomer seal, compression seal element, inflatable seal element, face seal, and all other methods and devices for engaging a polished bore receptacle and temporarily blocking the flow of fluids through the wellbore. Furthermore, the term “treatment fluid” includes any fluid delivered to a formation to stimulate production including, but not limited to, fracing fluid, acid, gel, foam or other stimulating fluid. Still furthermore, the terms “tubular member”, “casing”, and “liner” may be used interchangeably (e.g., any embodiment described herein for use with a casing may also be used with a liner or other tubular member). Yet furthermore, the term “polished bore receptacle” or “PBR” includes a smooth, polished, or honed bore formed on the inner surface of a tubular member (e.g., casing or liner) having a predetermined diameter for sealing or mating with a sealing mechanism.
Generally, this invention relates to a system and method for completing multi-zone wells by delivering a treatment fluid to achieve, facilitate, and/or improve productivity. Typically, such wells are completed in stages that result in very long completion times (e.g., on the order of four to six weeks). The present invention may reduce such completion time (e.g., to a few days) by facilitating multiple operations, previously done one trip at a time, in a single trip. Moreover, some embodiments of this invention provide a system and method for completing a well without the use of inflatable packers, which may need to be set and reset to facilitate multiple zonal isolations in a single run.
In one embodiment, PBRs 20A, 20B are installed only below the well zones 12A, 12B respectively. In this embodiment, the lower well zone 12B is perforated first. Then a sealing mechanism 30 is used to seal the tubular member 15 at PBR 20B. The well zone 12B is then treated via a fluid delivery device 40 on a tubing string 50. Next the upper well zone 12A is perforated. The sealing mechanism 30 is used to seal the tubular member 15 at PBR 20A and isolate well zone 12A from well zone 12B. The well zone 12A is then treated via a fluid delivery device 40.
In another embodiment, PBRs 20A, 20B are installed below the well zones 12A, 12B respectively and PBRs 22A, 22B are installed above the well zones 12A, 12B respectively. In this embodiment, the well zones 12A, 12B may both be perforated before any well zone 12A, 12B is treated. Once the well zones 12A, 12B are perforated, a straddling sealing mechanism (such as shown in
With reference to
In other embodiments of the present invention, instead of perforating and treating one well zone at a time, all well zones may be perforated before any well zone is treated. With respect to
In one embodiment, once the well zones are perforated, a well completion tool is provided to isolate and deliver a treatment fluid to each well zone. With respect to
In operation, the well completion tool is run in the casing 205 of a wellbore 200 to a target well zone 204 (
In an alternative embodiment of the present invention, a well completion tool is provided to deliver treatment fluid to isolated well zones, each of which have been perforated as shown in
Still with respect to
With respect to
Still with respect to
In some alternative embodiments of the present invention using PBRs to achieve zonal isolation in a wellbore, an anchoring device may be installed proximate to each PBR for the purpose of providing a positive location for depth control. The anchoring device may also support the weight of any dart or fluid delivery tools or applied forces produced from differential pressure across the seals of the PBRs and sealing mechanisms.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.
Claims
1. A system for use in a wellbore intersecting a well zone, comprising:
- a tubular member fixed in the wellbore;
- a polished bore receptacle arranged within the tubular member below the well zone;
- a tubing string for deployment in the wellbore;
- a fluid delivery assembly connected to the tubing string, the fluid delivery assembly having at least one port for establishing hydraulic communication between the tubing string and the wellbore; and
- a sealing mechanism connected below the fluid delivery assembly adapted to seal with the polished bore receptacle below the well zone.
2. The system of claim 1, further comprising:
- a polished bore receptacle arranged within the tubular member above the well zone; and
- a sealing mechanism connected above the fluid delivery assembly adapted to seal with the polished bore receptacle above the well zone.
3. The system of claim 1, further comprising:
- a perforating gun connected below the sealing mechanism.
4. The system of claim 1, further comprising:
- a line for deployment in the wellbore; and
- a perforating gun connected to the line.
5. The system of claim 1, wherein the sealing mechanism is selected from a group consisting of O-ring, chevron seal, V-packed seal, bonded elastomer seal, compression seal element, inflatable seal element, and face seal.
6. A system for use in a wellbore intersecting a well zone, comprising:
- a tubular member fixed in the wellbore;
- a first polished bore receptacle arranged within the tubular member above the well zone and a second polished bore receptacle arranged within the tubular member below the well zone;
- an outer tubing string having an upper end, a lower end, and an axial bore therethrough, the lower end of the outer tubing string being open to establish communication between the axial bore of the tubing string and the wellbore;
- an inner tubing string having an upper end, a lower end, and an axial bore therethrough, the inner tubing string residing within the axial bore of the outer tubing string;
- a diverter tool in connection with the lower end of the inner tubing string, the diverter tool having a port formed therein for establishing hydraulic communication between the axial bore of the inner tubing string and the wellbore;
- a first sealing mechanism arranged on the outer tubing string, the first sealing mechanism adapted to seal with the first polished bore receptacle; and
- a second sealing mechanism arranged below the port of the diverter tool, the second sealing mechanism adapted to seal with the second polished bore receptacle.
7. The system of claim 6, wherein the sealing mechanism is selected from a group consisting of O-ring, chevron seal, V-packed seal, bonded elastomer seal, compression seal element, inflatable seal element, and face seal.
8. A system for use in a wellbore intersecting a well zone, comprising:
- a tubular member fixed in the wellbore;
- a polished bore receptacle arranged within the tubular member below the well zone;
- a dart for pumping down the wellbore, the dart comprising a sealing mechanism adapted to seal with the polished bore receptacle; and
- a perforating gun connected above the dart.
9. The system of claim 8, further comprising:
- a transmitter arranged proximate the polished bore receptacle, the transmitter adapted to emit a particular signal; and
- a receiver connected to the dart, the receiver adapted to detect the signal from the transmitter,
- wherein the sealing mechanism is actuated between a collapsed and radially biased position as the receiver detects the signal.
10. The system of claim 9, wherein the perforating gun is fired after a predetermined delay as the receiver detects the signal.
11. The system of claim 9, wherein the sealing mechanism is selected from a group consisting of O-ring, chevron seal, V-packed seal, bonded elastomer seal, compression seal element, inflatable seal element, and face seal.
12. The system of claim 9, wherein the signal is selected from a group consisting of RF signal, radioactive signal, and magnetic signal.
13. The system of claim 8, wherein the dart further comprises:
- a fishing profile formed on the dart adapted to facilitate retrieval of the dart by a fishing tool.
14. The system of claim 8, wherein the dart further comprises:
- a centralizer adapted to maintain the alignment of the dart.
15. A method for use in a wellbore intersecting a well zone, comprising:
- providing a casing having a polished bore receptacle installed therein;
- installing the casing in the wellbore such that the polished bore receptacle is located below the well zone;
- providing a fluid delivery tool with a sealing mechanism connected therebelow;
- running the fluid delivery tool in the wellbore on a tubing string until the sealing mechanism seals with the polished bore receptacle; and
- delivering a treatment fluid to the well zone via the fluid delivery tool.
16. The method of claim 15, further comprising:
- connecting a perforating gun beneath the sealing mechanism; and
- perforating the well zone before delivering the treatment fluid.
17. The method of claim 15, further comprising:
- circulating sand proximate the well zone via the fluid delivery tool.
18. A method for use in a wellbore intersecting a well zone, comprising:
- providing a casing having at least two polished bore receptacle installed therein;
- installing the casing in the wellbore wherein at least one polished bore receptacle is located above the well zone and at least one polished bore receptacle is located below the well zone;
- providing a fluid delivery tool with a sealing mechanism connected above the fluid delivery tool and a sealing mechanism connected below the fluid delivery tool;
- running the fluid delivery tool in the wellbore on a tubing string until one sealing mechanism seals with one polished bore receptacle above the well zone and one sealing mechanism seals with one polished bore receptacle below the well zone; and
- delivering a treatment fluid to the well zone via the fluid delivery tool.
19. The method of claim 18, further comprising:
- perforating the well zone before delivering the treatment fluid.
20. The method of claim 18, further comprising:
- circulating sand proximate the well zone via the fluid delivery tool.
21. A method for use in a wellbore intersecting a well zone, comprising:
- providing a casing having at least two polished bore receptacle installed therein;
- installing the casing in the wellbore wherein at least one polished bore receptacle is located above the well zone and at least one polished bore receptacle is located below the well zone;
- providing a concentric tubing string comprising an inner string, an outer string, and a sealing mechanism arranged on the outer string;
- connecting a fluid delivery tool to the inner string with a sealing mechanism arranged below the fluid delivery tool;
- running the concentric string and fluid delivery tool in the wellbore until one sealing mechanism seals with one polished bore receptacle above the well zone and one sealing mechanism seals with one polished bore receptacle below the well zone; and
- delivering a treatment fluid to the well zone via the fluid delivery tool.
22. The method of claim 21, further comprising:
- delivering a treatment fluid to the well zone via the outer string.
23. The method of claim 21, further comprising:
- circulating sand proximate the well zone via the fluid delivery tool.
24. The method of claim 21, further comprising:
- circulating sand proximate the well zone via the outer string.
25. A method for use in a wellbore intersecting a well zone, comprising:
- providing a casing having a polished bore receptacle installed therein;
- installing the casing in the wellbore such that the polished bore receptacle is located below the well zone;
- providing a dart having a latching mechanism and a perforating gun attached thereto;
- pumping the dart in the wellbore until the sealing mechanism seals with the polished bore receptacle;
- perforating the well zone with the perforating gun; and
- delivering a treatment fluid to the well zone via the casing.
26. The method of claim 25, further comprising:
- actuating the sealing mechanism of the dart to expand radially outward to seal with the polished bore receptacle.
27. The method of claim 25, further comprising:
- actuating the sealing mechanism of the dart to collapse to disengage from the polished bore receptacle.
28. The method of claim 26, wherein actuating the sealing mechanism is achieved by sending a signal to the dart.
29. The method of claim 27, wherein actuating the sealing mechanism is achieved by sending a signal to the dart.
Type: Application
Filed: Dec 30, 2004
Publication Date: Jul 6, 2006
Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION (Sugar Land, TX)
Inventors: Jorge Lopez de Cardenas (Sugar Land, TX), Gary Rytlewski (League City, TX), Matthew Hackworth (Bartlesville, OK), John Whitsitt (Houston, TX), Jose Garcia (Sugar Land, TX)
Application Number: 10/905,372
International Classification: E21B 43/02 (20060101); E21B 43/11 (20060101);