Patent Application
20070246407
The present invention relates generally to equipment utilized and operations performed in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides inflow control devices for sand control screens.
Certain well installations benefit from having a flow restriction device in a well screen. For example, such flow restriction devices have been useful in preventing water coning, balancing production from long horizontal intervals, etc. These flow restriction devices are sometimes referred to as “inflow control devices.”
Unfortunately, typical inflow control devices rely on very small passages in orifices or nozzles to restrict flow, and typical inflow control devices cannot be conveniently adjusted at a jobsite, or are at least difficult to adjust. Small orifice passages are easily plugged, and the large pressure drop across an orifice tends to erode the passage relatively quickly. Convenient adjustment of the inflow control device at the jobsite is desirable, since exact well conditions and desired production parameters may not be known beforehand, and it is impractical to manufacture and warehouse well screens with inflow control devices configured for all possible conditions.
Therefore, it may be seen that improvements are needed in the art of well screens having inflow control devices. It is among the objects of the present invention to provide such improvements.
In carrying out the principles of the present invention, a well screen and associated inflow control device is provided which solves at least one problem in the art. One example is described below in which the inflow control device includes a flow restrictor which is conveniently accessible just prior to installing the screen. Another example is described below in which multiple flow restrictors are configured and positioned to provide enhanced flow restriction.
In one aspect of the invention, a well screen is provided which includes a filter portion. At least two flow restrictors are configured in series, so that fluid which flows through the filter portion must flow through each of the flow restrictors.
In another aspect of the invention, the well screen includes at least two tubular flow restrictors configured in series. The flow restrictors are positioned so that fluid which flows through the filter portion must reverse direction at least twice to flow between the flow restrictors.
In another aspect of the invention, a method of installing a well screen includes the steps of: providing the well screen including a filter portion and an inflow control device with at least one flow restrictor which restricts flow of fluid through the filter portion; and accessing the flow restrictor by removing a portion of the inflow control device.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers.
It is to be understood that the various embodiments of the present invention described herein 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 invention. The embodiments are described merely as examples of useful applications of the principles of the invention, which is not limited to any specific details of these embodiments.
In the following description of the representative embodiments of the invention, 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.
Representatively illustrated in
One or more of the well screens 16 may be positioned in an isolated portion of the wellbore 14, for example, between packers 18 set in the wellbore. In addition, or alternatively, many of the well screens 16 could be positioned in a long, continuous portion of the wellbore 14, without packers isolating the wellbore between the screens.
Gravel packs could be provided about any or all of the well screens 16, if desired. A variety of additional well equipment (such as valves, sensors, pumps, control and actuation devices, etc.) could also be provided in the well system 10.
It should be clearly understood that the well system 10 is merely representative of one well system in which the principles of the invention may be beneficially utilized. However, the invention is not limited in any manner to the details of the well system 10 described herein. For example, the screens 16 could instead be positioned in a cased and perforated portion of a wellbore, the screens could be positioned in a generally vertical portion of a wellbore, the screens could be used in an injection well, rather than in a production well, etc.
Referring additionally now to
A fluid 32 flows inwardly through a filter portion 26 of the screen 16. The filter portion 26 is depicted in
The fluid 32 enters an annular space 28 between the filter portion 26 and a tubular base pipe 90 of the screen 14. The fluid 32 then passes through an inflow control device 34, and into a flow passage 42 extending longitudinally through the screen 16. When interconnected in the tubing string 12 in the well system 10 of
Although the flow passage 42 is depicted in
The inflow control device 34 includes one or more flow restrictors 40 (only one of which is visible in
Although the inflow control device 34 is described herein as being used to restrict flow of fluid from the filter portion 26 to the flow passage 42, it will be appreciated that other configurations are possible in keeping with the principles of the invention. For example, if the flow passage is external to the filter portion 26, then the inflow control device could restrict flow of fluid from the flow passage to the filter portion, etc.
One advantage to using a tube for the flow restrictor 40 is that a larger inner diameter may be used to produce a restriction to flow which is equivalent to that produced by an orifice or nozzle with a smaller diameter passage. The larger inner diameter will not plug as easily as the smaller diameter passage. In addition, the extended length of the tube causes any erosion to be distributed over a larger surface area. However, an orifice or nozzle could be used in place of a tube for the flow restrictor 40, if desired.
In a beneficial feature of the screen 16 as depicted in
It will be appreciated that the opening 20 in the end wall 22 of the inflow control device 34 provides convenient access to the flow restrictor 40 at a jobsite. When the well conditions and desired production parameters are known, the appropriate flow restrictor 40 may be selected (e.g., having an appropriate inner diameter, length and other characteristics to produce a desired flow restriction or pressure drop) and installed in the inflow control device 34 through the opening 20.
To install the flow restrictor 40 in the inflow control device 34, appropriate threads, seals, etc. may be provided to secure and seal the flow restrictor. The plug 44 is then installed in the opening 20 using appropriate threads, seals, etc. Note that any manner of sealing and securing the flow restrictor 40 and plug 44 may be used in keeping with the principles of the invention.
Referring additionally now to
The inflow control device 34 includes multiple flow restrictors 24, 30 configured in series. The flow restrictors 24, 30 are in the shape of elongated tubes, similar to the flow restrictor 40 described above. However, in the embodiment of
Another cross-sectional view of the inflow control device 34 is illustrated in
In this view, the manner in which the flow restrictors 24, 30 are arranged in the device 34 to cause the fluid 32 to change direction may be clearly seen. The flow restrictors 24, 30 extend into a central chamber 36. Ends 38, 43 of the flow restrictors 24, 30 extend in opposite directions, and the flow restrictors overlap laterally, so that the fluid 32 is forced to reverse direction twice in flowing between the flow restrictors.
From the annular space 28, the fluid 32 flows into the flow restrictors 30 which are installed in a bulkhead 46. Any means of sealing and securing the flow restrictors 30 in the bulkhead 46 may be used. The flow restrictors 30 restrict the flow of the fluid 32, so that a pressure drop results between the annular space 28 and the chamber 36.
The pressure drop between the annular space 28 and the chamber 36 may be adjusted by varying the number of the flow restrictors 30, varying the inner diameter, length and other characteristics of the flow restrictors, replacing a certain number of the flow restrictors with plugs, replacing some or all of the flow restrictors with orifices or nozzles, not installing some or all of the flow restrictors (i.e., thereby leaving a relatively large opening in the bulkhead 46), etc. Although four of the flow restrictors 30 are depicted in
The flow restrictors 24, 30 may be conveniently accessed and installed or removed by removing an outer housing 48 of the device 34 (see
After the fluid 32 flows out of the ends 43 of the flow restrictors 30, the fluid enters the chamber 36. Since the ends 38, 43 of the flow restrictors 24, 30 overlap, the fluid 32 is forced to reverse direction twice before entering the ends 38 of the flow restrictors 24. These abrupt changes in direction cause turbulence in the flow of the fluid 32 and result in a further pressure drop between the flow restrictors 24, 30. This pressure drop is uniquely achieved without the use of small passages which might become plugged or eroded over time.
As the fluid 32 flows through the flow restrictors 24, a further pressure drop results. As discussed above, the restriction to flow through the flow restrictors 24 may be altered by varying the length, inner diameter, and other characteristics of the flow restrictors.
Due to this flow restriction, a pressure drop is experienced between the chamber 36 and another chamber 52 on an opposite side of a bulkhead 54 in which the flow restrictors 24 are installed. Any method may be used to seal and secure the flow restrictors 24 in the bulkhead 54, such as threads and seals, etc.
When the fluid 32 enters the chamber, another change in direction is required for the fluid to flow toward openings 56 which provide fluid communication between the chamber 52 and the flow passage 42. After flowing through the openings 56, a further change in direction is required for the fluid 32 to flow through the passage 42. Thus, another pressure drop is experienced between the chamber 52 and the passage 42.
It will be readily appreciated by those skilled in the art that the configuration of the inflow control device 34 as shown in
Referring additionally now to
Instead of the tubular flow restrictors 24, 30 of
The inner diameter and other characteristics of the flow restrictors 58, 60, 62 may also be changed as desired to vary the restriction to flow through the orifices. The flow restrictors 58, 60, 62 are depicted in
If the flow restrictors 58, 60, 62 are formed on separate members, then they may be provided with different characteristics (such as different inner diameters, etc.) to thereby allow a variety of selectable pressure drops between the annular space 28 and the chambers 52, 66, 68 in succession. In addition, any of the flow restrictors 58, 60, 62 could be left out of its respective bulkhead 46, 54, 64 to provide a relatively large opening in the bulkhead (to produce a reduced pressure drop across the bulkhead), or a plug may be installed in place of any orifice (to produce an increased pressure drop across the bulkhead).
The flow restrictors 58, 60, 62 may be accessed by removing the outer housing 48. Alternatively, openings and plugs (such as the opening 20 and plug 44 described above) may be provided in the end wall 22 to access the flow restrictors 58, 60, 62. In this manner, the flow restrictors 58, 60, 62 may be conveniently installed and otherwise accessed at a jobsite.
The flow restrictors 58, 60, 62 are configured in series, so that the fluid 32 must flow through each of the orifices in succession. This produces a pressure drop across each of the bulkheads 46, 54, 64. Although the flow restrictors 58, 60, 62 are depicted in
Referring additionally now to
The inflow control device 34 of
The flow restrictors 58, 24, 62 are still configured in series, so that the fluid 32 must flow through each of the flow restrictors in succession. Although the flow restrictors 58, 24, 62 are depicted in
Referring additionally now to
The inflow control device 34 of
In one unique feature of the inflow control device 34 of
Turbulence and a corresponding pressure drop results from each of these changes in direction of flow of the fluid 32. In addition, pressure drops are caused by the restrictions to flow presented by the flow restrictors 58, 72, 74. The flow restrictors 58, 72, 74 are configured in series, so that the fluid 32 must flow through each of the flow restrictors in succession.
Any number of the flow restrictors 58, 72, 74 may be used. Although the flow restrictors 72, 74 are depicted in
If the flow restrictors 72, 74 are formed on separate members, then they may be provided with different characteristics (such as different inner diameters, etc.) to thereby allow a variety of selectable pressure drops between the chambers 52, 68 and the chambers 52, 76 in succession. In addition, any of the flow restrictors 72, 74 could be left out of the manifold 70 to provide a relatively large opening in the manifold (to produce a reduced pressure drop across the manifold), or a plug may be installed in place of any flow restrictor (to produce an increased pressure drop across the manifold).
The manifold 70 and its flow restrictors 72, 74 may be conveniently installed or accessed by removing the outer housing 48. Alternatively, if any of the flow restrictors 58, 72, 74 are formed on separate members, they may be installed or accessed through openings and plugs (such as the opening 20 and plug 44 described above) in the end wall 22.
Referring additionally now to
The inflow control device 34 of
The configuration of
Referring additionally now to
The configuration of the inflow control device 34 as depicted in
Instead, the flow restrictor 80 is formed in a tubular member 82 which is sealingly and reciprocably received in a bore 84 formed in a housing 86. The housing 86 is illustrated in
As depicted in
The receiving device 88 has a bore 92 and a passage 94 formed therein. The bore 92 is for sealingly receiving the tubular member 82 therein, and the passage 94 provides fluid communication between the bore and the flow passage 42.
Thus, at a jobsite, when the well conditions and desired production characteristics are known, the appropriate tubular member 82 with an appropriate flow restrictor 80 therein may be inserted into the housing 86, and then the device 88 may be installed in the base pipe 90. Any number of the tubular member 82 may be used, and the flow restrictor 80 may be varied (for example, by changing an inner diameter or other characteristic of the flow restrictor) to provide a variety of restrictions to flow and pressure drops. The flow restrictor 80 may be formed in a separate member which is then installed (for example, by threading) in the tubular member 82.
In
To remove the tubular member 82, the snap ring 96 may be withdrawn from the recess 98, and then the tubular member may be displaced downward in the bore 84 of the housing 86. The receiving device 88 may then be detached from the base pipe 90 and the tubular member 82 may be withdrawn from the housing 86.
In use, the fluid 32 flows through the flow restrictor 80 in the tubular member 82, thereby producing a pressure drop between the annular space 28 and the flow passage 42. If multiple flow restrictors 80 are provided for in the inflow control device 34, then one or more of these may be replaced by a plug (e.g., by providing a tubular member 82 without the flow restrictor 80 formed therein) if desired to provide increased restriction to flow and a corresponding increased pressure drop between the annular space 28 and the flow passage 42.
Referring additionally now to
The inflow control device 34 differs from the other inflow control devices described above in at least one substantial respect, in that it includes a flow restrictor 100 which is installed in the base pipe 90. The flow restrictor 100 provides fluid communication between the flow passage 42 and a chamber 102 within a housing assembly 104 of the inflow control device 34.
Any number of the flow restrictors 100 may be provided. Each flow restrictor 100 may be formed in a separate member 106 installed in the base pipe 90 (for example, using threads and seals, etc.).
If multiple flow restrictors 100 are provided for in the inflow control device 34, then any of the members 106 may be replaced by a plug to increase the pressure drop between the chamber 102 and the flow passage 42. Alternatively, one or more of the members 106 may be left out to thereby provide a relatively large opening between the chamber 102 and the flow passage 42, and to thereby reduce the pressure drop.
The member 106 may be conveniently accessed by removing the housing assembly 104. The housing assembly 104 may include multiple housing members 108, 110 with a compression seal 112 between the housing members. When the housing assembly 104 is installed after accessing or installing the flow restrictor 100, the housing members 108, 110 are drawn together (for example, using threads, etc.) to thereby compress the seal 112 between the housing members and seal between the housing assembly and the base pipe 90.
Referring additionally now to
The inflow control device 34 as depicted in
An example of flow blocking members which may be used for the members 114, 116 is described in U.S. Published Application No. 2004/0144544, the entire disclosure of which is incorporated herein by this reference.
Another substantial difference is that the inflow control device 34 of
The members 114, 116 are preferably neutrally buoyant in water and, thus, are more dense than hydrocarbon fluid. Alternatively, the members 114, 116 may have a density which is between that of water and hydrocarbon fluid, so that they become buoyant when the fluid 32 contains a certain selected proportion of water.
Note that it is not necessary for the members 114, 116 to have the same buoyancy. For example, the member 114 may be designed to be buoyant in the fluid 32 when it has a certain proportion of water, and the member 116 may be designed to be buoyant in the fluid having another proportion of water.
In this manner, flow through the inflow control device 34 may be increasingly restricted as the proportion of water in the fluid 32 increases. This will operate to reduce the proportion of water produced in the well system 10.
If multiple flow blocking members 114 are provided in the chamber 66, it is not necessary for all of the members to have the same density. Similarly, if multiple flow blocking members 116 are provided in the chamber 68 it is not necessary for all of the members to have the same buoyancy. This is another manner in which increased restriction to flow may be provided as the fluid 32 contains an increased proportion of water.
Various relationships between the number of flow blocking members 114, 116 and respective flow restrictors 60, 62, 120, 122 are contemplated. For example, the number of members 116 in the chamber 68 may be less than the number of flow restrictors 60, 122, so that no matter the composition of the fluid 32, some flow will still be permitted between the chambers 66, 68, or between the chamber 68 and the flow passage 42. As another example, the number of members 116 may be equal to, or greater than, the number of flow restrictors 60, 122, so that flow from the chamber 68 to the chamber 66 or to the flow passage 42 may be completely prevented.
As depicted in
Note that it is not necessary for the specific combination of flow restrictors 58, 60, 62, 118, 120, 122 illustrated in
Note that it is also not necessary of the specific combination of flow blocking members 114, 116 illustrated in
Referring additionally now to
The inflow control device 34 as depicted in
However, note that the flow restrictor 122 is not provided in the inflow control device 34 of
As depicted in
Similar to the description above regarding the embodiment of the inflow control device 34 illustrated in
The various embodiments of the inflow control device 34 depicted in
In addition, other elements (such as other types of flow restrictors, filter portions, etc.) may be substituted for those described above in keeping with the principles of the invention. For example, any of the flow restrictors 24, 30, 40, 58, 60, 62, 72, 74, 78, 80, 100, 118, 120, 122 described above could be replaced with, or could incorporate, a helical flowpath or other type of tortuous flowpath, such as those described in U.S. Pat. No. 6,112,815, the entire disclosure of which is incorporated herein by this reference.
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, 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 invention. 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.
