Patent Application
20100252250
This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides for construction of well screens utilizing pre-formed annular elements.
Although most well screens perform a relatively simple function (filtering fluid which flows through the side of a tubing string), their design and construction is anything but simple. Very precise tolerances and carefully engineered structural capabilities are needed to enable well screens to exclude exactly the debris which should be excluded, without being overly flow restrictive, and to withstand the rigors of operating in a hostile downhole environment (e.g., conveyance into the well, corrosion, erosion during operation, etc.).
For these reasons (and others, such as, material availability, technical expertise, etc.), most well screens are manufactured in highly specialized factories which, unfortunately, are usually located great distances from where the well screens are to be ultimately installed. As a result, significant delay may be experienced in delivery of well screens to installation locations, local warehouses must be maintained to inventory well screens, custom well screen construction requires substantial advance planning, etc.
Therefore, it will be appreciated that improvements in the art of well screen construction are needed. These improvements would preferably address the problems mentioned above and/or produce other benefits, such as, reduced costs, improved reliability, flexibility of design and construction, etc.
In the disclosure below, a well screen is provided which solves at least one problem in the art. One example is described below in which a cavity is pre-formed in a layer of the well screen. Another example is described below in which a well screen layer is made up of multiple stacked ring-shaped elements.
In one aspect, a well screen is provided which includes a filter layer configured to filter fluid flowing through the well screen. A drainage layer is configured to support the filter layer. The drainage layer has at least one cavity molded therein.
In another aspect, a well screen is described below which includes a filter layer configured to filter fluid flowing through the well screen and a drainage layer which radially supports the filter layer. The drainage layer includes multiple individual annular-shaped elements.
In yet another aspect, a well screen includes a base pipe and a layer made up of multiple individual annular-shaped elements stacked coaxially on the base pipe. A cavity is formed in at least one of the elements. The layer may be a drainage layer or a filter layer. If the layer is a drainage layer, then it may radially support a filter layer.
The well screen could be used in production or injection operations, or in other types of operations (such as, completion, stimulation, conformance, etc.).
These and other features, advantages and benefits will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative examples below and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers.
Representatively illustrated in
At this point, it should be clearly understood that the well system 10 is described herein as merely one example of a wide variety of well systems which can incorporate the principles of this disclosure. For example, it is not necessary for the wellbore 14 to be vertical (the wellbore could instead be horizontal or inclined), and it is not necessary for the wellbore to be cased (e.g., the wellbore could be open hole or uncased adjacent the well screens 20 and/or packer 18). Any number of well screens 20 could be used for production from, or injection into, any number of zones 22. Thus, it should be appreciated that the principles of this disclosure are not limited in any manner to the details of the system 10 described herein.
One unique feature of the system 10 is that it includes the well screens 20 which are themselves uniquely configured to, for example, reduce costs of manufacturing, enable manufacture at diverse locations, ease assembly, provide for ready customization, and/or to allow for enhanced capabilities (such as incorporated sensing, telemetry, inflow control, etc.) in a convenient manner. Other capabilities and features can be included in the well screens 20 in keeping with the principles of this disclosure.
Referring additionally now to
The filter layer 28 is configured to filter fluid flowing into the well screen 20. The drainage layer 26 is configured to radially outwardly support the filter layer 28, so that fluid can readily flow through the filter layer and into the base pipe 24.
Of course, the drainage and filter layers 26, 28 can perform other functions in keeping with the principles of this disclosure. The drainage and filter layers 26, 28 could also be otherwise positioned, for example, with the drainage layer inwardly supporting the filter layer, if desired.
The filter layer 28 may be made of any type of material. For example, wire wraps, sintered metal, wire mesh, etc., are suitable for use in the filter layer 28. Materials such as metals, plastics and composites may be used, as well.
The drainage layer 26 may also be made of any type of material. Preferably, the drainage layer 26 is made up of stacked annular-shaped elements 30. These elements 30 are preferably made of molded plastic (such as injection molded phenolic or other thermoset plastic, polyetheretherketone, polyetherimide, polyphenylene sulfide, etc.).
However, other materials (such as cast metal, etc.) may be used if desired. Other manufacturing methods (such as stamping, etc.) could also be used if desired.
Furthermore, fillers or fibers could be added to a plastic matrix to form a composite structure for the elements 30. As another alternative, a layered material (for example, a base of a relatively inexpensive tough material, such as plastic, with a coating or outer layer of erosion-resistant and/or corrosion-resistant material, such as metal) may be used for the elements 30, if desired.
Since the drainage layer 26 is not normally intended for filtering the fluid flowing radially through the well screen 20, passages 32 formed axially between the elements 30 are preferably larger than passages 34 for flow through the filter layer 28, that is, the passages 32 have a greater minimum dimension than the passages 34. However, the passages 32 in the drainage layer 26 could have substantially the same minimum dimension as the passages 34 in keeping with the principles of this disclosure.
Although only the two layers 26, 28 are depicted in
The elements 30 of the drainage layer 26 are axially stacked on the exterior of the base pipe 24, but the passages 32 are formed axially between the elements due to protrusions 36 extending outwardly from each element. A biasing device 38 (such as a compression or wave spring) maintains axial compression on the stack of elements 30, so that the axial spacing of the elements remains consistent.
End rings 40 may be used to secure the layers 26, 28 on the base pipe 24, and to retain the biasing device 38. Alternatively, the ends of the layers 26, 28 could be crimped onto the base pipe 24, for example, as described in U.S. application Ser. No. 12/166,966 filed on Jul. 2, 2008, the entire disclosure of which is incorporated herein by this reference.
As depicted in
Thus, it will be readily appreciated that the features of the well screen 20 described above allow the well screen to be readily assembled and customized as needed at various locations by persons requiring relatively little training. For example, various lengths of well screen 20 may be assembled conveniently by merely varying the number of elements 30 stacked onto an appropriate length of base pipe 24, with an appropriate length of filter layer 28 installed thereon. Locally-sourced base pipe 24 can be used, with variations in outer diameter being accommodated by the elements 30. As such, the well screen 20 does not require a highly specialized manufacturing facility, but can instead be assembled at any of many locations in virtually any part of the world.
Referring additionally now to
However, preferably the gap 42 is not used. For example, other means may be used to accommodate varying outer diameters of the base pipe 24, other means may be used to provide for varying the circumferential length of the element 30, etc.
In
In
Referring additionally now to
Several benefits are derived by this engagement between the protrusions 36 and the recesses 52. One benefit is that the elements 30 are accurately spaced, with the passage 32 for fluid flow between the elements being determined by the difference between the length of the protrusions 36 and the depth of the recesses 52. Thus, by merely providing varied length protrusions 36 and/or varied depth recesses 52, the minimum dimension of the passages 32 can be conveniently varied, as desired.
Another benefit is that the engagement between the protrusions 36 and recesses 52 provides circumferential alignment of the adjacent elements 30. This alignment can be used to enable installation and accommodation of conduits, lines, sensors, etc. in the elements 30, as described more fully below.
Other methods of engagement are also possible, such as, snaps, clips, etc. Thus, the protrusion 36/recess 52 engagement could also provide a locking engagement, as well as spacing apart and circumferentially aligning the elements 30.
Note that the recesses 52 are not necessary to space the elements 30 apart and form the passages 32. Instead, only the protrusions 36 could be used for this purpose. Furthermore, the protrusions 36 could be other structural features used to space apart the elements 30, such as, separate spacers, undulations in the elements, features on the base pipe 24 or filter layer 28, etc.
Referring additionally now to
The cavities 56 are aligned with each other due to the engagement between the protrusions 36 and recesses 52 in this example. However, in other examples, a conduit 58 or other member extending through the cavities 56 could be used to align the cavities with each other, whether or not the protrusions 36 and/or recesses 52 are used.
The conduit 58 can serve as a fluid line, for example to hydraulically or pneumatically operate various well tools, sense downhole parameters, or for any other purpose. The conduit 58 can serve as a shunt tube for flowing a slurry across the well screen 20 during a gravel packing operation. The conduit 58 can serve any other purpose, as well, in keeping with the principles of this disclosure.
As depicted in
In addition, a sensor 62 is illustrated in
It will be appreciated that, if the cavities 56 are pre-formed in the elements 30, installation of the conduit 58, lines 60, sensor 62 and/or other components is made much more convenient. Preferably, the elements 30 are preferably molded with the cavities 56 therein, so that assembly of the well screen 20 is expedited and the overall cost of the well screen is reduced. Note that the cavities 56 may be used to accommodate components other than the conduit 58, lines 60 and sensor 62, as described more fully below.
Referring additionally now to
As depicted in
The inflow control devices 64, 66 may be used to control relative production from the zones 22 in the well system 10, for example, to reduce or eliminate water or gas coning. Suitable inflow control devices are described in U.S. Pat. Nos. 7,469,743 and 7,185,706, and in U.S. application Ser. No. 11/407,848 filed Apr. 20, 2006 and Ser. No. 11/671,319 filed Feb. 5, 2007. The entire disclosures of these prior patents and applications are incorporated herein by this reference. Other types of inflow control devices may be used, if desired.
Note that the elements 30 containing the inflow control devices 64, 66 are included in respective separate sets 68 of the elements spaced along the base pipe 24. In this manner, each of the elements 30 having the inflow control devices 64, 66 therein can separately regulate flow of fluid through the respective set 68, enabling much finer resolution of flow regulation along the tubular string 12 than previously possible.
For example, instead of flow through an entire 10 meter length well screen being regulated via a single inflow control device as in the past, the well screen 20 of
Referring additionally now to
The conduit 58 and/or lines 60 may be used to interconnect the telemetry devices 70, sensors 62 and/or power sources 72 along the well screen 20. The telemetry devices 70 may be positioned near ends of the well screen 20 to provide for communication between adjacent or spaced apart well screens, as described more fully below.
Referring additionally now to
In
In
Note that, in
Referring additionally now to
The direction of the J-shape can be alternated along the length of the well screen 20, so that the lines 60 are retained in the cavities 56 without need for any additional retainer or closure. However, a separate retainer or closure could be used, if desired. In addition, the lines 60 could be contained in the conduit 58 in the cavities 56, if desired.
The configuration of
Note that the layer 26 is depicted in
However, the separate filter layer 28 can be used on the configuration of
Referring additionally now to
As depicted in
In each of the embodiments described above, the elements 30 could be made in any length. For example, a relatively long element 30 could have multiple passages 32 formed therein, and multiple such long elements could be connected together, so that the passages 32 are not necessarily formed only by spacing apart the elements.
It may now be fully appreciated that the above disclosure provides many improvements to the art of well screen construction. Preferably, the described well screen 20 includes pre-formed (e.g., molded, extruded, cast, etc.) elements 30 which enable convenient, versatile and cost effective construction of the well screen, without requiring highly specialized assembly facilities and highly trained assembly personnel.
The above disclosure describes a well screen 20 which includes a filter layer 28 configured to filter fluid flowing through the well screen 20, and a drainage layer 26 configured to support the filter layer 28. The drainage layer 26 includes at least one cavity 56 molded therein.
The drainage layer 26 may include multiple individual annular-shaped elements 30. The cavity 56 may be molded in at least one of the elements 30.
A conduit 58 may extend through a plurality of the elements 30.
At least one line 60 may extend through a plurality of the elements 30. The line 60 may comprise at least one of an optical waveguide, an electrical line and a fluid line.
The elements 30 may be spaced apart from each other by at least one protrusion 36 formed on one or more of the elements 30. Each of the protrusions 36 may engage a respective recess 52 formed on an adjacent one of the elements 30, thereby circumferentially aligning the elements 30. The cavity 56 may be formed in the elements 30, such that circumferential alignment of the elements 30 by the protrusions 36 and recesses 52 also aligns the cavities 56 with each other.
The drainage layer 26 may be made of an electrically insulative material. The drainage layer 26 may have a greater minimum flow passage 32 dimension than the filter layer 28 (passages 34).
The well screen 20 may also include at least one of a sensor 62, a telemetry device 70 and an inflow control device 64, 66, positioned at least partially in the cavity 56.
Also provided by the above disclosure is a well screen 20 which combines a filter layer 28 configured to filter fluid flowing through the well screen 20 and a drainage layer 26 which radially supports the filter layer 28. The drainage layer 26 includes multiple individual annular-shaped elements 30.
Each of the elements 30 may include a cavity 56 formed therein, and the cavities 56 may be aligned with each other. The cavities 56 may be aligned by complementary protrusions 36 and recesses 52 formed on the elements 30. The protrusions 36 may space apart the elements 30, so that flow passages 32 are formed between the elements 30.
The well screen 20 may also include a conduit 58 extending through the aligned cavities 56. The well screen 20 may include at least one of an optical waveguide, an electrical line and a fluid line 60 extending through the aligned cavities 56.
The cavities 56 can comprise recesses 48 formed on an inner surface 44 of each of the elements 30. The recesses 48 may provide for longitudinal flow of fluid along an outer surface 50 of a base pipe 24 which extends through the elements 30.
The well screen 20 may include a cavity 56 molded in at least one of the elements 30. At least one of a sensor 62, a telemetry device 70 and an inflow control device 64, 66 may be positioned at least partially in the cavity 56.
The elements 30 may be made of an electrically insulative material.
Inflow control devices 64, 66 may be positioned in respective cavities 56 formed in respective ones of the elements 30. The inflow control devices 64, 66 may receive fluid flow from respective spaced apart sets 68 of the elements 30.
The elements 30 may be made of a material which comprises a thermoset plastic.
Also described above is a well screen 20 which combines a base pipe 24 and a layer 26 made up of multiple individual annular-shaped elements 30 stacked coaxially on the base pipe 24. A cavity 56 is formed in at least one of the elements 30.
The cavity 56 may be formed in the elements 30, whereby the layer 26 includes multiple cavities 56. The cavities 56 may be aligned with each other.
The cavities 56 may be aligned by complementary protrusions 36 and recesses 52 formed on the elements 30. The protrusions 36 may space apart the elements 30, so that flow passages 32 are formed between the elements 30.
A conduit 58 may extend through the aligned cavities 56. At least one of an optical waveguide, an electrical line and a fluid line 60 may extend through the aligned cavities 56.
The cavities 56 may comprise recesses 48 formed on an inner surface 44 of each of the elements 30, and the recesses 48 may provide for longitudinal flow of fluid along an outer surface 50 of the base pipe 24.
The well screen 20 may include at least one of a sensor 62, a telemetry device 70 and an inflow control device 64, 66, positioned at least partially in the cavity 56.
The cavity 56 may be disposed between inner and outer surfaces 44, 46 of at least one of the elements 30.
The first layer 26 may support a second layer 28 which is configured to filter fluid flowing into the well screen 20, with the first layer 26 being positioned between the second layer 28 and the base pipe 24.
It is to be understood that the various examples described above may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present disclosure. The embodiments illustrated in the drawings are depicted and described merely as examples of useful applications of the principles of the disclosure, which are not limited to any specific details of these embodiments.
In the above description of the representative examples of the disclosure, directional terms, such as “above,” “below,” “upper,” “lower,” etc., are used for convenience in referring to the accompanying drawings. In general, “above,” “upper,” “upward” and similar terms refer to a direction toward the earth's surface along a wellbore, and “below,” “lower,” “downward” and similar terms refer to a direction away from the earth's surface along the wellbore.
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are within the scope of the principles of the present disclosure. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
