BRIEF DESCRIPTION OF THE DRAWINGS
The following figures are part of the present specification, included to demonstrate certain aspects of presently preferred embodiments of the invention and referenced in the detailed description herein.
FIG. 1 is a partial cross-sectional view of an example base pipe and associated screen assembly in accordance with an embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view of the upper end of the screen assembly of the embodiment of FIG. 1;
FIG. 3 is an enlarged cross-sectional view of the fluid flow opening of the base pipe and the adjacent screen assembly of the embodiment of FIG. 1;
FIG. 4 is a partial cross-sectional view of an example base pipe and associated screen assembly in accordance with another embodiment of the present invention;
FIG. 5 is a partial cross-sectional view of an example base pipe, associated screen assembly and isolation flow assembly in accordance with an embodiment of the present invention;
FIG. 6 is an enlarged cross-sectional view of the upper end of the exemplary screen assembly of the embodiment of FIG. 5;
FIG. 7 is an enlarged cross-sectional view of an example locking mechanism of the embodiment of FIG. 5;
FIG. 8 is an enlarged cross-sectional view of an exemplary upper sealing assembly of the embodiment of FIG. 5;
FIG. 9 is an enlarged cross-sectional view of the fluid flow passage of the exemplary isolation member and adjacent fluid flow opening of the exemplary base pipe of the embodiment of FIG. 5; and
FIG. 10 is an enlarged cross-sectional view of an example lower sealing assembly of the embodiment of FIG. 5.
DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS
Characteristics and advantages of the present invention and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of presently preferred embodiments of the claimed invention and referring to the accompanying figures. It should be understood that the description herein and appended drawings, being of preferred embodiments, are not intended to limit the appended claims or the claims of any patent or patent application claiming priority to this application. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claims. Many changes may be made to the particular embodiments and details disclosed herein without departing from such spirit and scope.
In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
As used herein and throughout various portions (and headings) of this patent application, the terms “invention”, “present invention” and variations thereof are not intended to mean the invention of every possible embodiment of the invention or any particular claim or claims. Thus, the subject matter of each such reference should not be considered as necessary for, or part of, every embodiment of the invention or any particular claim(s) merely because of such reference. Also, it should be noted that reference herein and in the appended claims to components and aspects in a singular tense does not necessarily limit the present invention to only one such component or aspect, but should be interpreted generally to mean one or more, as may be suitable and desirable in each particular instance.
Referring initially to FIG. 1, in accordance with an embodiment of the present invention, a perforated base pipe 12 useful in a downhole fluid injection system is shown having a screen assembly 16 associated therewith. In this example, the base pipe 12 has a single fluid flow opening 20 (see also FIG. 3) through which fluid, such as steam, is injectable into an adjacent earthen formation 28. In other embodiments, the base pipe 12 may include multiple fluid flow openings 20, while certain embodiments may include multiple screen assemblies 16 associated with a single base pipe 12. Depending upon the application, the fluid may have any desired composition and characteristics. For example, the fluid may include water, steam, one or more chemical or solid, or a combination thereof. The fluid is in no way limiting upon the present invention.
The fluid flow opening 20 may have any desired form, configuration and orientation. In some embodiments, the fluid flow opening may be an angled or non-angled orifice (not shown) formed in the base pipe. In other embodiments, the fluid flow opening may include any desired component(s) having any suitable material construction, form and arrangement to provide wear resistance, injection control or other desired purpose. In FIG. 1, for example, the fluid flow opening 20 is shown angled at approximately 45 degrees in the direction of the lower end 14 of the base pipe 12, and includes a nozzle 30 constructed of wear-resistant material, such as tungsten carbide, screwed into the base pipe 12 and protruding therefrom. However, the fluid flow opening 20 may be provided at any desired angle.
In the embodiment of FIG. 4, a replaceable choke 32 is removably engaged with the base pipe 12. The choke 32 does not disturb or affect the base pipe 12/screen assembly 16 arrangement. The choke 32 and related components may have any suitable construction, form and configuration. The exemplary choke 32 includes a mandrel 34 having a predetermined-sized flow orifice 35, sealing members (not shown) above and below the orifice 35 and a mechanical locking device (not shown). The locking device, such as a wireline lock, may be used for engaging the choke 32 into upper and lower sealing profile members 36 formed into the base pipe 12 and allowing retrieval and removal of the choke 32. The exemplary choke 32 may be installed on the surface during assembly or remotely by wireline or pipe. Accordingly, the fluid injection scheme of the base pipe 12 may be changed during operations by replacing the choke 32.
Referring back to FIG. 1, the screen assembly 16 includes at least one screen member 40 (see also FIGS. 2 and 3) capable of blocking, or preventing, flowback of debris from the earthen formation 28 into the fluid flow opening 20 and base pipe 12. This feature may be useful, for example, during cessation of fluid injection from the base pipe 12 into the earthen formation. The screen member(s) 40 may have any suitable form, construction and configuration. For example, the screen member 40 may be a cylindrical wire wrap screen, mesh laminate, metal mesh or other filter media or material as is or become known. If desired, the screen member 40 may include multiple layers of filter media.
The screen assembly 16 is associated with the base pipe 12 in a manner that permits relative movement of the screen member 40 and base pipe 12 along the longitudinal axis 38 of the base pipe 12. Thus, the base pipe 12 may move longitudinally during operations without disturbing the screen member 40. For example, the screen member 40 or one or more related component may be shrunk fit onto the base pipe 12, as is or becomes known. The illustrated embodiment includes a pair of shrink-fit rings 44, 48 rigidly connected, such as by weld, to the screen member 40 and shrunk fit onto and in generally slideable sealing engagement with the base pipe 12 sufficient to maintain a desired seal and allow relative longitudinally movement therebetween. With this arrangement, under certain forces on the base pipe 12 and/or screen member 40, the base pipe 12 is capable of moving or expanding in either direction along its longitudinal axis 38 relative to the screen member 40.
One or more shear pin 52 that is releasably engageable between the base pipe 12 and screen assembly 16 or screen member 40 may be included. In the example of FIG. 1, upper and lower end rings 56, 60, each carrying a shear pin 52, are disposed around and longitudinally slideable over the base pipe 12. The illustrated end rings 56, 60 are rigidly connected, such as by weld, with the upper and lower shrink fit rings 44, 48, respectively (See also FIG. 2). The exemplary shear pins 52 maintain the positional relationship of the screen assembly 16 and base pipe 12 during installation, or deployment, of the base pipe 12, and thereafter will shear, or break away from the base pipe 12, under certain operating conditions.
Still referring to FIG. 1, the screen assembly 16 may also include a deflector 70 disposed at least partially between the base pipe 12 and the screen member 40 (see also FIGS. 2, 3). The deflector 70 may be useful, for example, to assist in protecting the screen member 40 from substantial damage by direct contact with fluid ejected through the fluid flow opening 20.
The deflector 70 may have any suitable form, configuration and orientation. In the embodiment shown, the deflector 70 is a generally solid tubular member 72 constructed of stainless steel and spanning substantially the entire length of the screen member 40. The illustrated deflector 70 is rigidly connected, such as by weld, to the upper and lower shrink fit rings, 44, 48 and is axially spaced from the base pipe 12 and screen member 40. The deflector 70 includes a port 74 to allow fluid injected from the fluid flow opening 20 into a gap 50 formed between the base pipe 12 and the deflector 70 to pass through the screen member 40 and into the earthen formation 28.
If desired, at assembly, the port 74 may be located in the deflector 50 a sufficient distance from the fluid flow opening 20 to prevent any occurrence of direct alignment of the fluid flow opening 20 with the port 74 and/or screen member 40 during operations. In FIGS. 1 and 2, the port 74 is positioned near the upper end 17 of the screen assembly 16 and spaced from the fluid flow opening 20 (at assembly) a distance estimated to be sufficient to avoid direct alignment therebetween prior to, during and after maximum possible relative longitudinal displacement of the base pipe 12 and screen assembly 16. For example, when the maximum expected thermal expansion of the base pipe 12 is between four and five feet in either direction, a pre-deployment distance between the port 74 and the fluid flow opening 20 of over five feet will prevent direct contact of the port 74, or screen member 40, by fluid as it is ejected through the fluid flow opening 20.
In some embodiments, the deflector 70 may include two or more ports. For example, in FIG. 4, a second port 74 is formed in the deflector 70 similarly distanced from the fluid flow opening 20 as the first port 74, but near the bottom end 18 of the screen assembly 16. Further, when multiple screen assemblies 16 are used with a string of connected base pipes 12 in an injection system, the ports 74 may be formed into the respective deflectors 70 with spacing to assist in achieving optimal fluid injection across the desired interval of earthen formation. For example, a port 74 may be located approximately every fifty meters in the injection system to effectively heat heavy oil or bitumen in the earthen formation.
However, the deflector 70 may take any other suitable form and configuration. For example, the deflector 70 may be a small plate (not shown) disposed in the proximity of the fluid flow opening(s) 20 between the base pipe 12 and screen member 40.
Referring again to FIG. 1, the screen assembly 16 may also include a perforated outer shroud 80 extending along the outer surface of the screen member 40, such as to assist in protecting the screen member 40 during deployment and/or operations. The outer shroud 80 may take any suitable form and configuration as is or becomes known. In the embodiment shown, the outer shroud 80 is a tube-shaped member 84 constructed of stainless steel. The tube-shaped member 84 is rigidly engaged with the upper and lower shrink fit rings, 44, 48, such as by weld, and axially spaced from the screen member 40.
In the embodiment of FIG. 1, the upper and lower end rings 56, 60, upper and lower shrink fit rings 44, 48, screen member 40, deflector 70 and outer shroud 80 move in unison relative to the base pipe 12. If desired, one or more stop member may be included to stop the relative movement of the base pipe 12 and screen assembly 16. For example, the stop member may be the collar 90 (FIG. 4) located proximate to one or both ends of the base pipe 12, a stop ring (not shown) or other component.
Now referring to the embodiment of FIG. 5, a replaceable isolation flow assembly 100 is insertable into and removably engageable with the base pipe 12. The isolation flow assembly 100 does not disturb or affect the relationship of the base pipe 12 and screen assembly 16. FIG. 6, for example, shows the screen assembly 16 and base pipe 12 arranged similarly as shown in the embodiment of FIG. 1 and described above.
The isolation flow assembly 100 and related components may have any suitable form, configuration and construction. In this example, the isolation flow assembly 100 includes an isolation member 106 and releasable locking assembly 112. The isolation member 106 is a tube-shaped mandrel 110 having a fluid flow passage 120 in fluid communication with the fluid flow opening 20 of the base pipe 12 when the isolation flow assembly 100 is engaged with the base pipe 12 (see also FIG. 9). Thus, the fluid injection scheme of the exemplary system may be changed based upon the size of the fluid flow passage 120 by installing or replacing the isolation flow assembly 100.
In the illustrated example, the fluid flow passage 120 is smaller than, and aligned with, the angularly oriented fluid flow opening 20. However, the present invention is not limited to this particular configuration—one or more fluid flow passage 120 of any desirable size and construction may be aligned as desired with one or more fluid flow opening 20 of the base pipe 12. Furthermore, the fluid flow passage 120 may have any desired form, configuration and orientation, and may include a nozzle or other desired components.
A guide member 114 may be included below the isolation member 106 to assist in guiding or positioning the isolation flow assembly 100 in the base pipe 12. For example, the guide member 114 may be a tube-shaped guide nose 116 threadably engaged with the lower end 108 of the isolation member 106.
Still referring to FIG. 5, the locking assembly 112 of this embodiment allows engagement and disengagement of the isolation flow assembly 100 and base pipe 12. In this example, the locking assembly 112 is threadably engaged with the upper end 107 of the isolation member 106 and includes a locking mechanism 124 engageable with the inner surface 13 of the base pipe 12. The locking mechanism 124 may have any suitable form and configuration. For example, referring to FIG. 7, the locking mechanism 124 may be an X-lock 128, such as the presently commercially available “TICX Locking Mandrel” by Tools International Company (TIC), which is constructed and operates as is known in the art. The example X-lock 128 includes two spring-biased keys 130 releasably mateable with profiles 134 formed or positioned at different locations on the inner circumference of the base pipe 12. If desired, the profiles 134 may be formed in one or more separate component (not shown) engaged with the base pipe 12.
Referring again to FIG. 5, the isolation flow assembly 100 of this embodiment also includes upper and lower sealing assemblies 140, 144. The illustrated sealing assemblies 140, 144 are capable of providing seals proximate to the upper and lower ends of a gap 150 formed between the isolation member 106 and the base pipe 12. The sealing assemblies 140, 144 may have any suitable form, configuration and construction. For example, referring to FIG. 8, the illustrated upper sealing assembly 140 is a packing stack 154 carried by the locking assembly 112. The illustrated lower sealing assembly 144, as shown in FIG. 10, is a packing stack 158 disposed in a space, or groove, 162 at the lower end 108 of the isolation member 106. In this example, the space 162 is disposed around a shoulder 109 of the isolation member 106 and between the isolation member 106 and the guide member 114. The exemplary guide member 114 thus assists in containing the packing stack 158. Each packing stack 154, 158 includes one or more sealing member constructed of any suitable desirable material, as is or becomes know.
In an example method involving use of the embodiment of FIG. 1 in an underground steam injection system, the base pipe 12 with screen assembly 16 is deployed into the earthen formation 28, such as via a borehole, as is or becomes known. During typical deployment, the shear pins 52 maintain engagement of the screen assembly 16 and base pipe 12 to prevent relative movement therebetween. As desired, steam is ejected from the base pipe 12 through the fluid flow opening 20 and into the gap 50. The port(s) 74 in the deflector 70 allow fluid to flow from the gap 50 through the screen member 40 and into the earthen formation 28. In this particular arrangement having a downwardly-oriented fluid flow opening 20, the steam will be expected, at least initially, to move toward the lower end 18 of the screen assembly 16 and thereafter toward the upper end 17 before exiting the port 74, such as in the example flow pattern shown with arrows 96.
The exemplary deflector 70 shields the screen member 40 from direct contact by fluid as it is ejected through the fluid flow opening 20. Upon a particular magnitude of thermal expansion of the base pipe 12 and/or restraint of the screen assembly 16 by formation collapsing and/or gravel-packing, the shear pin 52 will shear, allowing the base pipe 12 to move longitudinally relative to the end rings 44, 48 and screen assembly 16. Prior to, at and after maximum projected thermal expansion or longitudinal displacement of the base pipe 12, the fluid flow opening 20 will not align with the port(s) 74 of the deflector 70. The deflector 70 will continue to shield the screen member 40 from direct contact by fluid as it is ejected through the fluid flow opening 20. During cessation of fluid ejection through the fluid flow opening 20, the screen member 40 will prevent substantial flowback of debris through the port(s) 74, into the gap 50, fluid flow opening 20 and base pipe 12. However, the present invention is not limited by the above application or operation.
An example method of use of the embodiment of the isolation flow assembly 100 of FIG. 5 in an underground steam injection system will now be described. When it is desired to connect the isolation flow assembly 100 to the base pipe 12, the isolation flow assembly 100 is run into the base pipe 12, such as with the use of a wireline, or pipe, 166 connected to the upper end of the isolation flow assembly 100, as is or becomes know. The guide member 114, when included, assists in guiding the isolation flow assembly 100 into the base pipe 12 to the desired position. When the assembly 100 is located at the desired position within the base pipe 12, one or more locking mechanisms 124 are secured to the base pipe 12. In the illustrated embodiment, as shown in FIG. 7, each spring biased key 130 engages the corresponding mating profile 134 provided on the inner circumference of the base pipe 12. Fluid, such as steam, is injected into the isolation member 106 and out through its fluid flow passage 120, the through the fluid flow opening 20 of the base pipe 12 and the screen assembly 16 into the earthen formation 28. When it is desired to disconnect the isolation flow assembly 100 from the base pipe 12, the one or more locking mechanisms 124 are disengaged from the base pipe 12. A wireline or pipe 166 connected to the upper end of the isolation flow assembly 100 may be used to draw the isolation flow assembly 100 out of the base pipe 12.
Preferred embodiments of the present invention thus offer advantages over the prior art and are well adapted to carry out one or more of the objects of the invention. However, the present invention does not require each of the components and acts described above and is in no way limited to the above-described embodiments, methods of operation, variables, values or value ranges. Any one or more of the above components, features and processes may be employed in any suitable configuration without inclusion of other such components, features and processes. Moreover, the present invention includes additional features, capabilities, functions, methods, uses and applications that have not been specifically addressed herein but are, or will become, apparent from the description herein, the appended drawings and claims.
The methods described above and claimed herein and any other methods which may fall within the scope of the appended claims can be performed in any desired suitable order and are not necessarily limited to the sequence described herein or as may be listed in the appended claims. Further, the methods of the present invention do not necessarily require use of the particular embodiments shown and described in the present application, but are equally applicable with any other suitable structure, form and configuration of components.
While preferred embodiments of the invention have been shown and described, many variations, modifications and/or changes of the system, apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the patent applicant(s), within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of appended claims. Thus, all matter herein set forth or shown in the accompanying drawings should be interpreted as illustrative, and the scope of the invention and the appended claims should not be limited to the embodiments described and shown herein.