GB2365470A

GB2365470A - Method and apparatus for sand control in a subterranean well

Info

Publication number: GB2365470A
Application number: GB0118256A
Authority: GB
Inventors: Ralph H Echols; Perry C Shy
Original assignee: Halliburton Energy Services Inc
Current assignee: Halliburton Energy Services Inc
Priority date: 2000-07-27
Filing date: 2001-07-26
Publication date: 2002-02-20
Also published as: NO20013594D0; NO20013594L; GB0118256D0

Abstract

A method of radially expanding a sand-control screen jacket assembly 10 in a subterranean well 14 comprises the steps of inserting said assembly 10 and an expansion cone 52 into said well 14; pumping a sand-control medium 46 into the annular space 36 around said assembly 10; and moving said cone 52 through said assembly 10, causing said assembly 10 to expand radially. The expansion cone 52 can be inserted into the well before or after the sand-control medium 46 has been pumped, and may be driven by a self contained downhole force generator 54.

Description

<Desc/Clms Page number 1> METHOD AND APPARATUS FOR SAND CONTROL IN A SUBTERRANEAN WELL The present invention relates to sand-control apparatus for use in subterranean wells, and in particular relates to methods for open hole sand packing with expandable screens. Still more particularly, the invention relates to improved apparatus and methods for using a radially expandable sand-control screen jacket and sand or gravel packing in a subterranean well.

The control of the movement of sand and gravel into a well bore has been the subject of much importance in the oil production industry. The introduction of sand or gravel into the well bore commonly occurs under certain well conditions. The introduction of these materials into the well commonly causes problems including, plugged formations or well tubings, and erosion of tubing and equipment. There have therefore been numerous attempts to prevent the introduction of sand and gravel into the production stream.

One method of sand-control is the use of sand-control screen jackets to exclude sand from the production stream. The use of a radially expandable sand-control screen jacket includes causing the radial expansion of a base pipe and surrounding screen jacket by drawing a mechanical expansion tool up through the base pipe from the bottom of the hole. US 5,901,789, for example, discloses expanding a slotted steel tube by pulling an expansion cone upwardly through the tube. Problems exist in the practice of the art. One problem is that during expansion, the expansion tool can become lodged in the hole. In the current state of the art, it is very difficult to reverse the direction of the expansion tool to attempt to dislodge it.

Sand or gravel packing around the outside of a sand-control screen is sometimes performed in conjunction with sand-control screen installation. Sand or gravel packing is the controlled introduction of a selected sand or gravel into the annular space between a sand-control filter and the side of the wellbore. Generally, an attempt is made to entrap the selected packing medium in the annular space between the expanded screen and the edge of the hole. US 6,012,522 ('522) discloses the injection of bonding agent-coated granules into an expanded slotted tube, wiping the excess from the interior of the tube, and allowing the bonding agent to cure. Problems exist with this state of the art. The '522

method, has the problems noted above, in that the expansion cone can become lodged in the unexpanded tube. Additionally, the expansion cone is subject to becoming inadvertently bonded in place. Another problem is that the application of bonding agent- coated granules may leave gaps in coverage where sand can enter the production stream. Another problem with this method is the necessity of using a granule sized to fit through the tube slots. These problems may lead to the hole becoming filled with sand or in all of the sand washing out of the hole.

Due to the aforementioned problems with the introduction of sand and gravel into the production stream, a need exists for apparatus and methods for inserting a radially expandable sand-control screen jacket assembly into a well, radially expanding the screen jacket assembly, and sand or gravel packing the annular space between the expanded screen and the wall of the well.

In general, the invention provides apparatus and methods for injecting sand or gravel packing medium between a radially expandable sand-control screen jacket, and radially expanding the screen jacket with an expansion tool moving either downward or upward through the well. Packing medium granules can be sized to be excluded by the screen mesh. In a method of the invention for sand-control in a subterranean well, steps are taken to place a radially expandable sand-control screen jacket assembly into the well, place the expansion tool of the invention into the well, and move the expansion tool longitudinally through the well causing the screen jacket assembly to radially expand.

In one aspect of the invention, a sand-control medium is pumped into the well around the outer surface of the screen jacket assembly. In another aspect of the invention, the screen jacket assembly is expanded from the top down. In a further aspect of the invention, the screen jacket assembly is expanded from the bottom up. In yet another aspect of the invention, the expansion tool comprises a self-contained downhole force generator.

Reference is now made to the accompanying drawings in which: FIGURE 1 is a longitudinal cross-sectional view of a radially expandable sand- control screen jacket in a wellbore; FIGURE 2 is a longitudinal cross-sectional view of a radially expandable sand- control screen jacket, showing the expansion of the jacket in accordance with an embodiment of the invention; and

FIGURE 3 is a longitudinal cross-sectional view of a radially expandable sand- control screen jacket, showing the expansion of the jacket in accordance with another embodiment of the invention.

The present invention is describe with reference to drawings showing one or more examples of how the invention can be made and used. In these drawings, reference characters are used throughout the several views to indicate like or corresponding parts.

In the description which follows, like or corresponding parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the invention. In the following description, the terms "upper," "upward," "lower," "below," downhole", "longitudinally" and the like, as used herein, shall mean in relation to the bottom, or furthest extent of, the surrounding wellbore even though the wellbore or portions of it may be deviated- or horizontal. Correspondingly, the "transverse" orientation shall mean the orientation perpendicular to the longitudinal orientation. The term "sand-control" used herein means the exclusion of particles larger in cross section than a chosen size, whether sand, gravel, mineral, soil, organic matter, or a combination thereof.

Apparatus and methods for constructing and deploying screen jackets are used in conjunction with the invention, but are not critical thereto. Exemplary sand-control screens and methods of their deployment in a well are disclosed in US 5,931,232 and US 5,850,875.

Referring in general to Figures 1-3, the general structure and methods of using the radially expandable sand-control screen jacket assembly 10 utilizing the present inventive concepts is shown. The radially expandable screen jacket assembly 10 is inserted into the production zone 12 of a wellbore 14. It should be understood that the screen jacket assembly 10 need not be located at the end 16 of the wellbore 14 as shown in Figures 1 and 2. As shown in Figure 3, the screen jacket assembly 10 may of course be connected to a casing 18 at either end. The connection 20 between the casing 18 and the screen jacket assembly 10 may be made in the conventional manner and is not critical to the inventions so long as a sand -controlling joint is provided. The wellbore 14 is substantially cylindrical but typically has irregularities such as gaps 22 randomly distributed throughout its length. The screen jacket assembly 10 has a base pipe 24 at its center. The base pipe

24 has a plurality of perforations 26 through which fluids in the well enter the interior of the base pipe 24. Throughout the Figures, the sand-control screen jacket assembly 10 is referred to generally with the numeral 10. When differentiating between the expanded and unexpended states of the screen jacket assembly, the illustrations carry the additional designations 10a, referring specifically to the unexpended screen jacket assembly, and 10b, referring specifically to the expanded screen jacket assembly. The sand-control screen jacket assembly 10 may be comprised of one or more concentric inner 28 and outer screens 30 with or without a layer of prepacked sand 32 between screens. The screen jacket assembly 10 may optionally have a screen shroud 34 concentrically surrounding the screens 28, 30. The exact configuration of the screen jacket assembly 10 is not critical to the invention and may be varied by those skilled in the arts. With the screen jacket assembly 10 inserted into the desired location of the wellbore 14 in the conventional manner, an annular space 36 exists between the outer surface 38 of the screen jacket assembly 1 Oa and the wall of the wellbore. 14.

With further reference to Figure 1, a wash pipe 40 is inserted into the unexpended screen jacket assembly 1 Oa. The terminal end 42 of the wash pipe 40 is equipped with an outlet valve or nozzle, preferably a float shoe 44. The other end of the wash pipe 40 is connected to a pump (not shown). In practicing the invention a packing medium 46, such as sand granules of a selected size suspended in slurry, is pumped into the annular space 36 between the unexpended screen jacket assembly 1 Oa and the wall of the wellbore 14. The annular space 36 is typically not filled or tightly packed with packing medium 46. Space is left to allow for expansion of the screen jacket 10. Of course, as further discussed below with reference to Figure 3, in cases where an additional pipe string portion is located downhole from the screen jacket assembly 10, the wash pipe extends a location where the packing medium-slurry mixture is injected into a port in a conventional manner. It will also be apparent to those skilled in the arts that additional fluid such as a gel medium (not shown) may be pumped into the welibore in order to help position the packing medium. The wash pipe 40 is preferably removed after a predetermined quantity of packing medium 46 has been pumped into the annular space 36.

Referring now primarily to Figure 2, after the wash pipe (not shown) has been removed, the expansion tool 50 is positioned at the upper end of the sand-control screen jacket 1 0a. An expansion cone 52 portion of the expansion tool is preferably

mechanically connected to a hydraulic downhole force generator 54. The downhole force generator 54 is preferably self-contained, or may be in communication to the surface via slickline, power connections, or control connections. Optionally, the weight of the work string may be applied to the expansion tool to supply downward force. The exact configuration of the expansion tool is not critical to the invention so long as sufficient force is applied to facilitate longitudinal movement of the tool and radial expansion of the screen jacket. The unexpanded screen jacket 10a is forced radially outward by the expansion cone 52, to produce expanded screen jacket 10b. In practicing the inventions, the expansion tool 50 may be moved further downhole and activated as many times as required to expand the screen jacket assembly 10 for the desired length of wellbore 18. After the screen jacket 10 expands, the packing medium 46 preferably substantially fills the annular space 36 between the screen jacket assembly 10 and the wellbore 14. It is not critical to the invention that the annular space 36 be filled, completely or substantially, when the screen jacket 10 is in its expanded state. Those skilled in the art will of course realize that the expansion aspect of the invention may be practiced without the introduction of packing medium 46 into the wellbore.

In an alternative embodiment of the inventions depicted in Figure 3, a casing 18 extends in either direction in the wellbore 14 with a production zone 12 located therebetween. The expansion tool 50 is placed downhole of the production zone 12. A sand-control screen jacket assembly 10 is then deployed spanning the production zone 12. A gel medium 68 and packing medium 46 may then in turn be introduced into the wellbore 14 by a pump and wash pipe (not shown) such that packing medium 46 is held in the production zone 12. The gel medium 68 and packing medium 46 are preferably injected into the wellbore 14 through a port 70 in the casing 18. However, the gel and packing medium may alternatively be injected and pumped to position from the bottom of the hole. The unexpanded screen jacket 10a is forced radially outward by the expansion cone 52, to produce expanded screen jacket 10b. The downhole force generator 54 may be self-contained as preferred, or may be in communication to the surface via slickline, power connections, or control connections. In practicing the inventions, the expansion tool 50 may be moved further upward and activated as many times as required to expand the screen jacket assembly 10 for the desired length of wellbore 14. As the screen jacket 10 expands, the packing medium 46 preferably , but not necessarily, substantially fills the

annular space 36 between the screen jacket assembly 10b and the wellbore 14. Those skilled in the arts will of course realize that the expansion aspect of the invention may be practiced without the introduction of packing medium 46 into the wellbore.

It will be clear to those skilled in the art that either embodiment described herein may be practiced with either screen jacket assembly deployment in a production zone described. It will also be clear that the apparatus and methods disclosed may be used for top-down or bottom-up screen expansion. The invention has several advantages over the apparatus and methods previously known in the art, including the advantages of providing thorough gravel packing around the wellbore and the ability to expand a screen jacket assembly moving in either the downhole or upward direction. Additionally, the combination of an expandable screen jacket assembly with appropriately sized packing medium placed outside the screen jacket assembly provides better assurance of achieving a sand -controlling surface than methods which rely on pressing a small-particle sand-controlling medium through a relatively large-mesh screen jacket assembly. The self-contained expansion tool also provides advantages including the elimination of surface connections.

The embodiments shown and described above are only exemplary. Many details are often found in the art such as: screen or expansion cone configurations and materials. Therefore, many such details are neither shown nor described.

It will be appreciated that the invention described above may be modified.

Claims

CLAIMS: 1. A method of sand-control in a subterranean well, comprising the steps of: inserting a radially expandable sand-control screen jacket assembly into the well and thereafter pumping sand-control medium into the annular space between the outer surface of the screen jacket assembly and the wellbore wall; inserting an expansion tool into the well; and moving the expansion tool through the screen jacket assembly causing the screen jacket assembly to radially expand.
2. A method according to claim 1, wherein the expansion tool is moved through the screen jacket assembly from top to bottom.
3. A method according to claim 1 or 2, wherein the expansion tool further comprises a self-contained downhole force generator.
4. A method according to claim 1, 2 or 3, wherein the packing medium substantially fills the annular space between the outer surface of the screen jacket assembly and the wellbore wall after the step of moving the expansion tool through the screen jacket assembly.
5. A method of sand-control in a subterranean well, comprising the steps of: inserting an expansion tool into the well; then inserting a radially expandable screen jacket assembly into the well above the expansion tool; then pumping sand-control medium into the annular space between the outer surface of the screen jacket assembly and the wellbore wall; and moving the expansion tool through the screen jacket assembly causing the screen jacket assembly to radially expand.
6. A method according to claim 5, wherein the expansion tool further comprises a self- contained downhole force generator.
7. A method according to claim 5 or 6, wherein the packing medium substantially fills the annular space between the outer surface of the screen jacket assembly and the

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wellbore wall, after the step of moving the expansion tool through the screen jacket assembly.
8. A method according to claim 5, 6 or 7, wherein the expansion tool is moved through the screen jacket assembly from top to bottom.
9. Apparatus for radially expanding a sand-control screen jacket assembly in a subterranean well, comprising: an expansion cone; anda downhole force generator operably connected to the expansion cone for moving the expansion cone through the sand-control screen jacket assembly and causing the screen jacket assembly to radially expand.
10. Apparatus according to claim 10, wherein the downhole force generator is selfcontained.
11. Apparatus according to claim 9 or 10, wherein the downhole force generator further comprises an electric battery operably connected to an electric motor.
12. Apparatus according to claim 9, 10 or 11, wherein the downhole force generator further comprises an activation assembly.
13. A method of sand-control in a subterranean well substantially as herein described with reference to and as shown in the accompanying drawings.
14. Apparatus for radially expanding a sand-control screen jacket assembly in a subterranean well with reference to and as shown in the accompanying drawings.