SYSTEM FOR COMPLETING MULTIPLE WELL INTERVALS
A system and method for completing a well with multiple zones of production is provided, including a casing having a plurality of valves integrated therein for isolating each well zone, establishing communication between each underlying formation and the interior of the casing, and delivering a treatment fluid to each of the multiple well zones. Furthermore, the present invention further discloses mechanisms for actuating one or more of the valves including, but not limited to, a dart, a drop ball, a running tool, and control line actuating system.
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This application is a divisional of U.S. patent application Ser. No. 10/905,073, filed Dec. 14, 2004, and entitled “System For Completing Multiple Well Intervals.”
BACKGROUND OF THE INVENTION1. 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 production zones.
2. 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 pumped 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 production zones. According to some embodiments of the present invention, a well completion system having one or more zonal communication valves is installed and/or deployed in a wellbore to provide zonal isolation and establish hydraulic communication with each particular well zone for facilitating delivery of a treatment fluid.
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: packers, bridge plugs, downhole valves, sliding sleeves, baffle-plug combinations, polished bore receptacle (PBR) seals, and all other methods and devices for 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.
Generally, this invention relates to a system and method for completing multi-zone wells by delivering a treatment fluid to achieve 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.
Regarding use of the well completion system of the present invention, some embodiments may be deployed in a wellbore (e.g., an open or uncased hole) as a temporary completion. In such embodiments, sealing mechanisms may be employed between each valve and within the annulus defined by the tubular string and the wellbore to isolate the formation zones being treated with a treatment fluid. However, in other embodiments the valves and casing of the completion system may be cemented in place as a permanent completion. In such embodiments, the cement serves to isolate each formation zone.
Actuation of the zonal communication valve may be achieved by any number of mechanisms including, but not limited to, darts, tool strings, control lines, and drop balls. Moreover, embodiments of the present invention may include wireless actuation of the zonal communication valve as by pressure pulse, electromagnetic radiation waves, seismic waves, acoustic signals, and other wireless signaling.
In some embodiments of the dart of the present invention, the latching mechanism 110 is static in that the latching mechanism is biased radially outward to engage the mating profile 37 of the sleeve 36 of the first valve 25 encountered (see
In some embodiments, the dart may include a sealing mechanism to prevent treatment fluid from passing below the dart once it is latched with the sliding sleeve of the valve. With respect to
In another embodiment of the well completion system of the present invention, with reference to
In yet other embodiments of the present invention, the valves of the well completion system may be actuated by a network of control lines (e.g., hydraulic, electrical, fiber optics, or combination). The network of control lines may connect each of the valves to a controller at the surface for controlling the position of the valve. With respect to
In still other embodiments of the well completion system of the present invention, the actuation mechanism for actuating the valves may include a set of drop balls. With respect to
With respect to
With respect to
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 having a plurality of well zones, comprising:
- a casing fixed to the wellbore by cement;
- a plurality of valves connected to the casings, each valve comprising: (i) a flow port for establishing communication between the casing and one of the well zones, and
- (ii) a sliding sleeve disposed therein for regulating communication via the flow port, the sliding sleeve having an axial bore therein with a mating profile;
- an actuating tool comprising a collet adapted to selectively engage with the mating profile of the sliding sleeve of each of the plurality of valves; and
- a work string connected to the actuating tool, the work string adapted to axially move the actuating tool in the wellbore.
2. The system of claim 1, further comprising:
- a coating applied to the housing of each of the plurality of valves, the coasting adapted to decrease the bond of the cement to the housing.
3. The system of claim 1, further comprising:
- a plurality of lobes formed on the housing of each of the plurality of valves, each lobe protruding radially outward toward the wellbore to decrease the volume of cement residing in an annulus defined by the housing and the wellbore,
- wherein a recess is defined between any two adjacent lobes to permit cement to pass through the annulus during cementing operations.
4. The system of claim 1, where in the collet is pumped downhole on a dart and the dart is adapted to shift the sliding sleeve between an open port position and a closed port position.
5. The system of claim 1, wherein establishing communication between the casing and one of the well zones comprises pumping the collet on a dart from the surface into the casing to move the axial bore on the sliding sleeve into an open position.
6. The system of claim 5, further comprising:
- delivering a treatment fluid to one of the well zones via the open position.
7. The system of claim 1, wherein the collet is run downhole on the work string.
8. The system of claim 1, wherein the collet includes a plurality of fingers having protruding elements for engaging the mating profile of the sliding sleeve when the collet is run downhole on the work string.
9. The system of claim 1, further comprising:
- a controller included in the actuating tool comprising the collet for receiving pressure pulses emitted from a surface.
10. The system of claim 8, wherein the collet may be actuated between a first position where the fingers are retracted and a second position where the fingers are moved to extend radially outward.
11. The system of claim 9, wherein the collet is actuated when the controller receives receiving pressure pulses emitted from the surface.
12. The system of claim 1, further comprising:
- a controller included in the actuating tool comprising the collet for receiving pressure pulses emitted from a surface.
13. The system of claim 12, wherein the work string is a slickline.
14. The system of claim 13, wherein the actuating tool includes a tension converter for delivering a signal to the controller of the actuating tool by vertical motion in the slickline.
15. The system of claim 14, wherein the signal is selected from a group consisting of a radio frequency signal, an acoustic signal, a radioactive signal, and a magnetic signal.
16. The system of claim 1, further comprising:
- the collet includes a plurality of fingers having one end fixed to the actuating tool and another end having a protruding element formed thereon, the collet moveable between a first position whereby the plurality of fingers are retracted and a second position whereby the plurality of fingers are extended radially outward; and
- a working string for suspending the collet in the wellbore,
- wherein the mating profile on the sliding sleeve is adapted to receive the protruding elements of the plurality of fingers of the collet when the collet is in the second position.
17. A method for use in a wellbore having a plurality of well zones, comprising:
- running a casing having a plurality of valves formed therein from a surface down into the wellbore such that each valve is proximate a well zone;
- cementing the casing to the wellbore;
- opening at least one of the valves to establish communication between the surface and the wellbore; each valve comprising: (i) a flow port for establishing communication between the casing and one of the well zones, and (ii) a sliding sleeve disposed therein for regulating communication via the flow port, the sliding sleeve having an axial bore therein with a mating profile; and wherein opening at least one of the valves includes: actuating an actuating tool comprising a collet adapted to selectively engage with the mating profile of the sliding sleeve of each valve, wherein the actuating tool is connected to a work string which is adapted to axially move the actuating tool in the wellbore.
18. The method of claim 17, wherein establishing communication between the casing and one of the well zones comprises pumping the collet on a dart from the surface into the casing to move the axial bore on the sliding sleeve into an open position.
19. The system of claim 18, further comprising:
- delivering a treatment fluid to one of the well zones via the open position.
20. The system of claim 17, wherein the collet includes a plurality of fingers having protruding elements for engaging the mating profile of the sliding sleeve when the collet is run downhole on the work string.
Type: Application
Filed: Aug 7, 2007
Publication Date: Nov 29, 2007
Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION (Sugar Land, TX)
Inventors: JORGE LOPEZ DE CARDENAS (Sugar Land, TX), GARY RYTLEWSKI (League City, TX), MATTHEW HACKWORTH (Manvel, TX)
Application Number: 11/834,869
International Classification: E21B 43/17 (20060101);