Method and Apparatus for Completion of Heavy Oil Unconsolidated Sand Reservoirs
A method of completing a subterranean well having a well casing extending though an earth formation is provided, including the steps of: suspending an apparatus at a selected depth within the well casing; creating an unbalanced condition within the well casing; forming a lateral bore in the formation by jetting a pressurized fluid from the apparatus through a casing opening in the well casing and into the earth formation; receiving in the well casing through the casing opening fluid and formation debris created from forming the lateral bore; and lifting the fluid and formation debris received by the well casing upwardly through the well casing to the well surface.
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This application is a continuation of International Application No. PCT/IB2011/054841, filed Nov. 1, 2011, which is a non-provisional of U.S. Application No. 61/409,622, filed Nov. 3, 2010.
FIELD OF THE INVENTIONThe present invention relates generally to methods and systems for enhancing heavy oil productivity from unconsolidated sand reservoirs and, in illustrated embodiments thereof, more particularly relates to a method and apparatus for completion of heavy oil unconsolidated sand reservoirs.
BACKGROUND OF THE INVENTIONHeavy oil production with sand is becoming an increasingly used technique for certain types of heavy oil deposits. Allowing sand production can dramatically improve oil recovery compared to the non-sand production process. The advantage of allowing sand production is that the produced sand creates high permeability zones comprising of relatively small channels for the heavy oil to flow through. However, a challenge with heavy oil production with sand is keeping the sand moving freely and consistently into the wellbore.
Conventional, explosive charge well perforation or completion which creates relatively small diameter holes in the well casing for the production of formation fluid from the reservoir has experienced sporadic success with heavy oil production with sand. This is attributed to experiencing in-flow problems caused by fine sand and clay migration or reservoir sand sloughing that plugs the small diameter casing holes created by the explosive charge perforation completion process.
In an attempt to improve well productivity, and to alleviate the plugging problems associated with conventional explosive charge perforation, horizontal drilling and horizontal radial water-jetting methods have been implemented in the completion of unconsolidated sand reservoirs. However, each of these methods has achieved nominal success. It is believe the low success is attributed to performing these methods in an overbalanced condition, that is, in a condition in which fluid pressure in the wellbore is maintained higher than the pressure of the reservoir. In this condition, sand loosened from the horizontal drilling and horizontal radial water-jetting is pushed back into the reservoir. It is believed this causes instability in the manufactured bores and results in eventual collapse or closure of the channel due to sand sloughing.
Considering the advantage of high permeability verse the challenge of high sand production in heavy oil unconsolidated sand reservoirs a need exists for an improved completion method and apparatus that provides an unrestricted near well-bore access in heavy oil sand producing wells. It is to this need that the present invention is directed.
SUMMARY OF THE INVENTIONIn carrying out the principles of the present invention, in accordance with representative embodiments thereof, a well casing perforation and formation boring tool and methods of the same for the completion of a subterranean well, and particularly, a heavy oil unconsolidated sand reservoir in an underbalanced condition is provided.
Embodiments of the present invention also provide for a low impact completion when compared to conventional explosive charge completions, which alleviate concern of damaging cement encasement that is critical in providing isolation from water zones above or below the productive formation.
Embodiments of the present invention further provide tools and methods for forming a large well-bore access area and a high permeability lateral bore or cavern deep within the reservoir providing enhanced connection between the well and reservoir. The large sand face or reservoir contact area provided by the high permeability bore reduces reservoir fluid velocities and is believed to minimize or eliminate problematic sand and clay production.
Embodiments of the present invention further provide tools and methods that can be implemented on existing completed wells that are experiencing problematic in-flow or poor production due to near well bore formation damage.
To achieve these and other advantages, in general, in one aspect, a method of completing a subterranean well extending through an earth formation is provided, including the steps of: creating an underbalanced condition in the well; providing a nozzle in the well; and pumping a pressurized fluid through the nozzle such that a jet of the pressurized fluid ejects from the nozzle and impinges on the earth formation creating a lateral bore in the earth formation.
The method may further include the steps of: providing a flexible hose to which the nozzle is attached and extending the flexible hose fitted with the nozzle into the earth formation from the well.
In general, in another aspect, a method of completing a subterranean well having a well casing extending though an earth formation is provided, including the steps of: suspending an apparatus at a selected depth within the well casing; creating an unbalanced condition within the well casing; forming a lateral bore in the formation by jetting a pressurized fluid from the apparatus through a casing opening in the well casing and into the earth formation; receiving in the well casing through the casing opening fluid and formation debris created from forming the lateral bore; and lifting the fluid and formation debris received by the well casing upwardly through the well casing to the well surface.
In general, in another aspect, a method of completing a subterranean well having a well casing extending through an earth formation is provided, including the steps: providing a well perforation and completion tool including a body having a circumferential wall, an internal axial flow passage extending through an end of the body and terminating through the circumferential sidewall forming a side port, one or more lateral ports extending through the circumferential wall and providing fluid communication between the internal axial flow passage and a position exteriorly of the body, and an abrasive jet perforation nozzle disposed in each of the lateral ports; suspending the well perforation and completion tool at a selected depth within the well casing; pumping a high pressure abrasive fluid through the internal axial flow passage such that a jet of the high pressure fluid ejects out of each of the perforation nozzles to form a perforation in the well casing; moving the well perforation and completion tool in the well casing while maintaining the azimuth position of the well perforation and completion tool relative to the well casing while pumping the high pressure fluid to form a casing slot through the well casing; configuring the well perforation and completion tool for well completion; creating an underbalanced condition in the well casing; extending a hose having attached thereto an excavation nozzle from the apparatus through the side port and through the casing slot and into the earth formation; and pumping a pressurized excavation fluid through the hose such that a jet of the pressurized excavation fluid ejects out of the excavation nozzle and impinges the earth formation to form a lateral bore in the earth formation while extending the hose.
In general, in another aspect, a casing perforation and formation boring tool for use in connection with the completion of a subterranean well is provided, the tool including: a body having a circumferential wall, an internal axial flow passage extending through an end of the body and terminating through the circumferential sidewall forming a side port, one or more lateral ports extending through the circumferential wall and providing fluid communication between the internal axial flow passage and a position exteriorly of the body, and a landing seat disposed across the internal axial flow passage at a position between the one or more lateral ports; the internal axial flow passage configured to receive a tube therein; the landing seat configured to receive a blanking plug to isolate the one or more lateral ports from the side port; and an abrasive perforation nozzle disposed in each of the one or more lateral ports.
In an aspect, the tool may also include a flexible hose disposed and extensible within the internal flow passage; a hydraulic excavation nozzle connected to a downhole end of the flexible hose; and a guide wheel guiding the distal end of the flexible hose through the side port.
In an aspect, the tool may also include a pipe disposed within the internal axial flow passage; a pipe coupling connect to an top hole end of the pipe; and a hydraulic excavation nozzles connected to a downhole end of the pipe, the hydraulic excavation nozzle aligned with the side port and configured to jet a stream of pressurized fluid flowing through the pipe.
In an aspect, the tool may also include an alignment tab carried by the body and extensible between a retracted position and an extended position.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated embodiments of the invention.
The following drawings illustrate by way of example and are included to provide further understanding of the invention for the purpose of illustrative discussion of the embodiments of the invention. No attempt is made to show structural details of the embodiments in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Identical reference numerals do not necessarily indicate an identical structure. Rather, the same reference numeral may be used to indicate a similar feature of a feature with similar functionality. In the drawings:
As a preliminary matter, it should be noted that in this document (including the claims) directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., without departing from the principles of the invention.
Representatively illustrated in
The abrasive jet perforation sub 14 has at least one, and preferably has a plurality of lateral ports 26 extending through the circumferential wall thereof. In one embodiment, there are three lateral ports 26 arranged in a triangular configuration. In another embodiment, there are four lateral ports 26 arranged in a boxed or diamond configuration. The lateral ports 26 provide fluid communication between the internal axial flow passage 22 and a position exteriorly of the abrasive jet perforation sub 14. An abrasive jet perforation nozzle 28 is disposed in each of the lateral ports 26 for the passage of the high pressure abrasive cutting fluid used to cut a slot into the well casing and cement encasement as will be further described below. Lateral ports 26 and nozzles 28 are preferably configured to cut a one-inch wide slot through the well casing and cement encasement.
Further, it is of importance to note, the lateral ports 26 and the side port 24 are disposed on the same side of body 12 and are generally vertically aligned about the circumference of the body.
Landing nipple 16 connects the abrasive jet perforation sub 14 and the jetting shoe 18 and provides a landing seat 30 across the internal axial flow passage 22 for the reception of a removable blanking plug 40 to seal the internal axial flow passage and isolate the jetting shoe from a flow of fluid through the internal axial flow passage in a well casing perforation operation as will be described in further detail below. The blanking plug 40 may include a fishing neck 41 to permit retrieval of the blanking plug through known methods.
Jetting shoe 18 is configured to receive the passage of an extensible hydraulic excavator (
Jetting shoe 18 further includes an extensible alignment tab 34 that laterally moves relative to the jetting shoe between a retracted position, shown in
Wiper sub 20 is attached to the bottom of the jetting shoe 18 and includes one or more radially extending seal members 38. The seal member 38 is configured to making a circumferential sealing contact with the internal surface of the well casing and provides well casing isolation from lower completion zones.
In
An alternate embodiment 18a of the jetting shoe 18 is shown in
In
Turning now to
Turning now to
With the guide tab 34 in this position, the extensible hydraulic excavator 42 is connected to tubing 48 and comprising hose 44 and nozzle 46 is run-in through tubing 68 and internal axial flow passage 22. Upon the nozzle 46 reaching the guide wheel 32, the nozzle and the hose 44 are fed through the side port 24 and through the casing slot 72, at which it is positioned and oriented laterally against the formation 66 in which a lateral bore radially extending from the well bore 60 is to be completed.
At this point, the well bore 60 is placed into an underbalanced condition, wherein the pressure within the well casing 62 is lower than the formation pressure, by a continuous injection of stable foam through tubing 68 and the internal axial flow passage 22 where it is ejected from the side port 24. The stable foam 74 is returned to the surface through well casing 62. Once the stable foam 74 is initially returned to the surface, pressurized fluid, such as, for example water is then pumped through tubing 48, through hose 44 and jetted from nozzle 46 where it impinges against the unconsolidated sand formation 66 forming a lateral bore 76 therein. The underbalanced condition of the well bore 60, as result of the injection of stable town 74, causes sand slurry and fluids, admixed with the stable foam, to flow outwardly from the lateral bore 76 and into the well casing 62 through the casing slot 72. Once in the well casing 62, the sand slurry, fluid and stable foam are further mixed within a mixing chamber 78 defined by a lateral recessed profile 80 in the exterior circumferential wall of the jetting shoe 18 and the well casing 72. The recessed profile 80 is further illustrated in
The hose 44 and nozzle 46 are fed continuously into the unconsolidated sand formation 66 from the tool 10 until a lateral bore 76 reaches a desired radial depth from the well bore 60. The hose 44 and nozzle 46 may be alternately withdrawn and extended (guided by guide wheel 32) to achieve the desired radial depth, which may be up to 150-feet. As this operation continues, an increasing volume of sand is flushed into the well casing 62 creating a high permeability bore 76 deep into the unconsolidated sand formation 66.
Once bore 76 reaches a desired depth, water jetting injection is terminated, and the hose 44 and nozzle 46 are withdrawn into the jetting shoe 18 and the excavator 42 is withdrawn from tool 10 and pulled to the surface. Stable foam injection continues until the surface returns are clear of sand providing an indication that completion at this interval is finished, and at which point, the stable foam injection is terminated. Tool 10 is then withdrawn slowly causing the alignment tab 34 to be retracted once it reaches the top of the casing slot 72. Tool 10 may be withdrawn a certain distance to align the tool with another completion zone or may be completely withdrawn from the well bore 60. In multiple completions with tool 10, the lowest or deepest zone would be completed first with successive zones being completed at the tool is withdrawn. The wiper sub 20 isolates completed zones as the tool 10 is withdrawn and is operated to complete a subsequent zone.
The above description in reference to methods of operating tool 10 and the above description of tool 10a with reference to
Further, it should be noted excavation nozzles 46 and 56 may be of any known type or conventional in the art. In an embodiment, and for example, as illustrated in
With reference to
A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
Claims
1. A method of completing a subterranean well extending through an earth formation, the method comprising the steps of:
- creating an underbalanced condition in the well;
- providing a nozzle in the well; and
- pumping a pressurized fluid through said nozzle such that a jet of said pressurized fluid ejects from said nozzle and impinges on the earth formation creating a lateral bore in the earth formation.
2. The method of claim 1, further comprising:
- providing a flexible hose to which said nozzle is attached; and
- extending said flexible hose fitted with said nozzle into the earth formation from the well.
3. The method of claim 1, wherein the step of creating includes:
- injecting a stable foam into the well.
4. A method of completing a subterranean well having a well casing extending though an earth formation, the method comprising the steps of:
- suspending an apparatus at a selected depth within the well casing;
- creating an unbalanced condition within the well casing;
- forming a lateral bore in the formation by jetting a pressurized fluid from said apparatus through a casing opening in the well casing and into the earth formation;
- receiving in the well casing through the casing opening fluid and formation debris created from forming said lateral bore; and
- lifting the fluid and formation debris received by the well casing upwardly through the well casing to the well surface.
5. The method of claim 4, wherein said step of creating includes:
- injecting stable foam into the well casing.
6. The method of claim 5, wherein said stable foam is injected from said apparatus.
7. The method of claim 4, wherein said forming step includes:
- extending a hose having attached thereto and excavation nozzle from said apparatus and through the casing opening and into the earth formation.
8. A method of completing a subterranean well having a well casing extending though an earth formation, the method comprising the steps of:
- suspending an apparatus at a selected depth within the well casing;
- creating an underbalanced condition in the well casing;
- forming a longitudinal casing slot through the well casing by jetting a high pressure abrasive fluid from said apparatus at said well casing to make a perforation in the well casing while translating said apparatus in one of a withdrawal or extending direction in the well casing;
- forming a lateral bore in the formation by jetting a pressurized fluid from said apparatus through said casing slot and into the earth formation;
- receiving in the well casing through the casing slot fluid and formation debris created from forming said lateral bore; and
- lifting the fluid and formation debris received by the well casing upwardly through the well casing to the well surface.
9. The method of claim 8, wherein said step of creating includes:
- injecting stable foam into the well casing.
10. The method of claim 9, wherein said stable foam is injected from said apparatus.
11. The method of claim 8, wherein said forming step includes:
- extending a hose having attached thereto and excavation nozzle from said apparatus and through the casing opening and into the earth formation.
12. A method of completing a subterranean well having a well casing extending though an earth formation, the method comprising the steps of:
- providing a well perforation and completion tool including a body having a circumferential wall, an internal axial flow passage extending through an end of said body and terminating through said circumferential sidewall forming a side port, one or more lateral ports extending through said circumferential wall and providing fluid communication between said internal axial flow passage and a position exteriorly of said body, and an abrasive jet perforation nozzle disposed in each of said lateral ports;
- suspending said well perforation and completion tool at a selected depth within the well casing;
- pumping a high pressure abrasive fluid through said internal axial flow passage such that a jet of said high pressure fluid ejects out of each of said perforation nozzles to form a perforation in the well casing;
- moving said well perforation and completion tool in the well casing while maintaining the azimuth position of said well perforation and completion tool relative to the well casing while pumping said high pressure fluid to form a casing slot through the well casing;
- configuring said well perforation and completion tool for well completion;
- creating an underbalanced condition in the well casing;
- extending a hose having attached thereto an excavation nozzle from said apparatus through said side port and through said casing slot and into the earth formation; and
- pumping a pressurized excavation fluid through said hose such that a jet of said pressurized excavation fluid ejects out of said excavation nozzle and impinges the earth formation to form a lateral bore in the earth formation while extending said hose.
13. The method of claim 12, wherein said step of creating includes:
- pumping a stable foam through said internal axial flow passage such that said stable foam exits said side port and into the well casing.
14. The method of claim 12, further comprising the step:
- engaging a guide tab with said casing slot to align said side port with said casing slot.
15. The method of claim 14, wherein said engaging step said guide tab extends from said body and into said casing slot.
16. A casing perforation and formation boring tool for use in connection with the completion of a subterranean well, the tool comprising:
- a body having a circumferential wall, an internal axial flow passage extending through an end of said body and terminating through said circumferential sidewall forming a side port, one or more lateral ports extending through said circumferential wall and providing fluid communication between said internal axial flow passage and a position exteriorly of said body, and a landing seat disposed across said internal axial flow passage at a position between said one or more lateral ports;
- said internal axial flow passage configured to receive a tube therein;
- said landing seat configured to receive a blanking plug to isolate said one or more lateral ports from said side port; and
- an abrasive perforation nozzle disposed in each of said one or more lateral ports.
17. The tool of claim 16, further comprising:
- a well casing isolation seal carried by said body at a position downhole end from said side port.
18. The tool of claim 16, further comprising:
- a flexible hose disposed and extensible within said internal flow passage;
- a hydraulic excavation nozzle connected to a downhole end of said flexible hose; and
- a guide wheel guiding said distal end of said flexible hose through said side port.
19. The tool of claim 16, further comprising:
- a pipe disposed within said internal axial flow passage;
- a pipe coupling connect to an uphole end of said pipe; and
- a hydraulic excavation nozzles connected to a downhole end of said pipe, said hydraulic excavation nozzle aligned with said side port and configured to jet a stream of pressurized fluid flowing through said pipe.
20. The tool of claim 16, further comprising:
- an alignment tab carried by said body and extensible between a retracted position and an extended position.
Type: Application
Filed: Oct 8, 2012
Publication Date: Apr 10, 2014
Applicant: (Calgary)
Inventor: Gary Freitag (Calgary)
Application Number: 13/646,800
International Classification: E21B 7/04 (20060101); E21B 43/114 (20060101); E21B 29/06 (20060101); E21B 7/18 (20060101);