[0001] The field relates to packers used in the oil and gas industry.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. l is a schematic showing a casing with a compression packer in a wellbore.

[0003] FIG. 2 is a cross section of the compression packer in a run-in position.

[0004] FIG. 3 is a cross section of the compression packer after it has been moved to a set position.

[0005] FIG. 4 is a cross section of the compression packer after it has been moved to a completed position.

DESCRIPTION OF AN EMBODIMENT

[0006] In the drawings and description that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. In addition, similar reference numerals may refer to similar components in different embodiments disclosed herein. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is not intended to limit the invention to the embodiments illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed herein may be employed separately or in any suitable combination to produce desired results.

[0007] Unless otherwise specified, use of the terms "connect," "engage," "couple," "attach," or any other like term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. [0008] Unless otherwise specified, use of the terms "up," "upper," "upward," "up-hole," "upstream," or other like terms shall be construed as generally toward the surface; likewise, use of "down," "lower," "downward," "down-hole," "downstream," or other like terms shall be construed as generally away from the surface, regardless of the wellbore orientation. Use of any one or more of the foregoing terms shall not be construed as denoting positions along a perfectly vertical axis. A wellbore can include vertical, inclined or horizontal portions, and can be straight or curved.

[0009] FIG. 1 shows apparatus 20, which in one embodiment is a compression packer 20 lowered into a wellbore 10 on a casing string 15. In the embodiment described, apparatus 20 is used in a portion of wellbore 10 in which a casing 5 has already been installed. Compression packer 20 is a stand-alone packer, and is designed for efficient use in shallow wells, for example around 200 feet or less, and wells with low pressure and temperature, for example below 3000 psi and 200° F. While the compression packer is particularly suited for use in such wells, it may be used in deeper wells and wells with higher temperatures and pressures. Compression packer 20 is designed to support a hydrostatic column of cement and uses only one plug to set the compression packer 20. Other tools, such as for example a stage cementing tool 25 may be included in the casing string 15. Any number of different tools may be connected in casing string 15 and used in connection with compression packer 20. A minimum amount of drill out is needed after the compression packer 20 is set, since only a single plug is required to set the compression packer 20.

[00010] An annulus 30 is defined by and between packer 20 and wellbore 10. Although depicted in wellbore 10 with casing 5 therein, it is understood that use of the compression packer 20 is not so limited, and may be used in an uncased wellbore. Likewise, while compression packer 20 is shown in a vertical wellbore, it is understood that the compression packer 20 may be used in a deviated, or a horizontal wellbore. Compression packer 20 comprises a packer body 32 with upper end 34 and lower end 36. Compression packer 20 is shown in a first, or run-in position 38 in FIG. 2. Compression packer 20 is shown in a second, or set position 40 in FIG. 3 and in a third, or completed position 42 in FIG. 4. An adapter 44 may be connected at upper end 34 of packer body 32 to connect in casing string 15. Compression packer 20 defines a central flow passage 46 therethrough and has inner surface 48 and exterior, or outer surface 50. [00011] A sliding sleeve 52 is slidably disposed in packer body 32. Sliding sleeve 52 is shown in a first position 54 in FIG. 1, which corresponds to the run-in position 38 of the compression packer 20, a second position 56 in FIG. 2 which corresponds to the set position 40, and a third position 58 in FIG. 4, which corresponds to the completed position 42 of compression packer 20. A plug seat 60 is defined at upper end 62 of sliding sleeve 52. Plug seat 60 may be a separate piece connected to sliding sleeve 52 or may be integrally formed on sliding sleeve 52.

[00012] A setting sleeve 64 is disposed about packer body 20 and is slidable thereon. Setting sleeve 64 is connected to sliding sleeve 52 with shearable drive pins 66. Slots 68 with upper end 70 and lower end 72 are defined in packer body 32. Setting sleeve 64 has upper end 74 and lower end 76. Lower end 76 is a flat, or snub-nosed end 76, which may be described as a flat annular face.

[00013] A plurality of locking elements 80 are disposed in grooves 82 in setting sleeve 64. Locking elements in one embodiment may comprise lock rings 84 and a biasing element 86, which may comprise a wave spring that biases a lock ring 84 toward packer body 32.

[00014] A packer stop 90 is attached to packer body 32 and may be threaded thereto. Packer stop 90 has upper end 92 and lower end 94. Upper end 92 is a flat, snub nosed stop 92, which may be described as a flat annular face. Lock screws 96 may be used to hold packer stop 90 in place. A packer element 98 is disposed about packer body 32 and has upper and lower ends 100 and 102 respectively.

[00015] An upper anti-extrusion element 104 covers upper end 100 of packer element 98 and has an upwardly extending leg 105. Leg 105 encircles packer body 32 above packer element 98. A lower anti-extrusion element 106 covers lower end 102 of packer element 98 and has a downwardly extending leg 107. Leg 107 encircles packer body 32 below packer element 98. An annular space 108 is defined by and between setting sleeve 64 and packer body 32 at the lower end 76 of setting sleeve 64. Leg 105 is positioned in space 108, and is captured between packer body 32 and setting sleeve 64 at lower end 76 thereof. An annular space 112 is defined by and between packer stop 90 at the upper end 92 of packer stop 90. Leg 107 is positioned in space 112, and is captured between packer body 32 and packer stop 90 at upper end 92 thereof. [00016] In operation, the apparatus 20 is lowered into a wellbore on casing string 15. Once the desired depth is reached, apparatus 20 may be moved to the set position in which packer element 98 is expanded radially outwardly to engage wellbore 10, which in the embodiment described is a cased wellbore, but which may also be an uncased wellbore. Packer element 98 is moved outwardly solely by placing the packer element 98 in compression, as opposed to using inflation, or the use of wedges and ramps which are commonly used to expand packer elements in other packer tools. Apparatus 20 is moved to the set position with the use of a setting plug 110. Setting plug 110 is passed into casing 15 and will be moved downwardly therein until setting plug 110 engages setting plug seat 60. Once setting plug 110 engages setting plug seat 60, pressure is increased to move sliding sleeve 52 downwardly in packer body 32. Setting sleeve 64 will move downwardly with sliding sleeve 52 since setting sleeve 64 and sliding sleeve 52 are connected with frangible drive pins 66. Pressure is continuously applied so that setting sleeve 64 is pushed into packer element 98.

[00017] Compression is applied to packer element 98 by the annular flat face at the lower end 76 of setting sleeve 64 to the upper end 100 of packer element 98. Packer stop 90 is fixed to packer body 32 and is stationary. Packer element 98 is prevented from moving downward by the annular flat upper face at the upper end 92 of packer stop 90. Compression is applied to packer 98 until it expands radially outwardly sufficiently to move to the set position 40 in which packer element 98 engages and seals against wellbore 10 Locking elements 80 are biased toward packer body 32, and will be urged into grooves in the packer body 32 to hold setting sleeve 64 in place in its set position. Pressure is continuously applied in casing 15 until a sufficient pressure, which may be a predetermined pressure, is reached to apply a force to drive pins 66 that is sufficient to break the frangible drive pins 66. Once drive pins 66 are broken, sliding sleeve 52 will move downwardly in packer body 32 so that the apparatus 20 is in its completed position 42, in which setting sleeve 64 is fixed to packer body 32 with locking elements 80 such that it maintains compression on packer element 98 to keep the apparatus 20 in its set position. No ramps or wedges are used to expand packer element 98, and the radial expansion of packer element 98 is caused solely by the compassion applied by setting sleeve 64. In addition, no communication is allowed from central flow passage 46 to the annulus 30 through packer body 32, either before or after compression packer 20 is moved to the set position. [00018] Upper anti -extrusion element 104 captures upper end 100 of packer element 98 so that packer element 98 does not extrude around setting sleeve 64, and does not intrude into any gaps that may exist between setting sleeve 64 and packer body 32. Leg 105 of anti-extrusion element 104 occupies the space defined between setting sleeve 64 and packer body 32 to prevent the packer element 98 from intruding, or squeezing into that space. Lower anti-extrusion element 106 captures lower end 102 of packer element 98 so that packer element 98 does not extrude around packer stop 90, and does not intrude into any gaps that may exist between packer stop 90 and packer body 32. Leg 107 of anti-extrusion element 106 occupies the space defined between packer stop 90 and packer body 32 to prevent the packer element 98 from intruding, or squeezing into that space.

[00019] While compression packer 20 may be used in connection with stage cementing processes, it is understood that the compression packer 20 is usable with other downhole tools and in other scenarios in which a packer is needed.

[00020] Embodiments include:

[00021] Embodiment 1. A stand-alone packer comprising a packer body; a compressible packer element having an upper end and a lower end disposed about the packer body; a setting sleeve disposed about the packer body above the compressible packer element; a packer stop having a flat annular upper face positioned on the packer body below the compressible packer element; and a sliding sleeve disposed in the packer body and detachably connected to the setting sleeve.

[00022] Embodiment 2. The stand-alone packer of embodiment 1 further comprising: an upper anti-extrusion element capturing an upper end of the compressible packer element and having a portion thereof disposed between the setting sleeve and the packer body; and a lower anti-extrusion element capturing a lower end of the compressible packer element and having a portion thereof disposed between the packer stop and the packer body.

[00023] Embodiment 3. The stand-alone packer of any of embodiments 1 and 2, the setting sleeve movable from a first to a second position on the packer body to urge the second end of the packer element against the flat annular upper face of the packer stop. [00024] Embodiment 4. The stand-alone packer of any of embodiments 1 -3, the sliding sleeve movable in the packer body to move the setting sleeve from a first to a second position, the setting sleeve being movable therewith, wherein the compressible packer element is squeezed between the setting sleeve and the packer stop to expand the packer element radially outwardly to engage the wellbore.

[00025] Embodiment 5. The stand-alone packer of embodiment 4, the sliding sleeve being detachable from the setting sleeve and movable longitudinally relative thereto to a third position in the packer body.

[00026] Embodiment 6. The stand-alone packer of any of embodiments 4 and 5, further comprising a plurality of locking elements disposed in grooves in the setting sleeve and movable therewith, the packer body having a plurality of grooves defined in an outer surface thereof, the plurality of locking elements being received in the grooves in the packer body to lock the setting sleeve in the second position.

[00027] Embodiment 7. The stand-alone packer of embodiment 6, further comprising a biasing element engaging the locking elements and urging the locking elements into the grooves in the packer body.

[00028] Embodiment 8. The stand-alone packer of embodiment 4, the sliding sleeve defining a plug seat for receiving a setting plug, the sliding sleeve movable in the packer body as a result of pressure applied in the packer body above the setting sleeve.

[00029] Embodiment 9. A downhole tool comprising a tubular body connected in a casing string for use in a wellbore, the tubular body and wellbore defining an annulus therebetween; a radially expandable compression packer element disposed about the tubular body; a packer stop having a flat annular upper face disposed about the tubular body below a lower end of the compression packer element; and a setting sleeve disposed about the tubular body above an upper end of the packer element wherein the packer element expands outwardly to engage the wellbore as a result of compression resulting from movement of the setting sleeve from a first to a second position on the tubular body, the tubular body being isolated from the annulus such that no communication from a central flow passage of the tubular body to the annulus is possible therethrough prior to or after the compression packer element is expanded outwardly to engage the wellbore.

[00030] Embodiment 10. The downhole tool of embodiment 9, the setting sleeve comprising a generally cylindrical body with upper and lower ends, the lower end defining a flat annular surface adjacent the upper end of the compression packer element.

[00031] Embodiment 11. The downhole tool of any of embodiments 9 and 10, further comprising an upper anti-extrusion ring capturing an upper end of the compression packer element, a portion of the anti-extrusion ring being trapped between the setting sleeve and the tubular body to prevent the compression packer element from intruding between the setting sleeve and the tubular body.

[00032] Embodiment 12. The downhole tool of embodiment 11, further comprising a lower anti-extrusion ring capturing a lower end of the packer element, a portion of the lower antiextrusion ring positioned between the packer stop and the tubular body to prevent the packer element from intruding between the packer stop and the tubular body.

[00033] Embodiment 13. The downhole tool of any of embodiments 9-12, further comprising a sliding sleeve disposed in the tubular body and a plurality of frangible connectors connecting the sliding sleeve to the setting sleeve.

[00034] Embodiment 14. The downhole tool of embodiment 13, the frangible connector comprising a shearable drive pin.

[00035] Embodiment 15. The downhole tool of any of embodiments 9-14, further comprising a plurality of retaining rings movable with the setting sleeve, the tubular body defining a plurality of grooves for receiving the retaining rings in the second position of the setting sleeve.

[00036] Embodiment 16. A downhole tool comprising a tubular body; a packer element having upper and lower ends; a packer stop disposed about the tubular body having a flat annular upper face; a setting sleeve having a flat annular lower face and being movable from a first to a second position on the tubular body; an upper anti-extrusion element at the upper end of the packer element; and a lower anti-extrusion element of the lower end of the packer element, wherein the packer element is squeezed between the flat annular lower face of the setting sleeve and the flat annular upper face of the packer stop to expand the packer element radially outwardly and engage a wellbore when the setting sleeve moves to the second position.

[00037] Embodiment 17. The downhole tool of embodiment 16, further comprising a sliding sleeve disposed in the tubular body and detachably connected to the setting sleeve.

[00038] Embodiment 18. The downhole tool of embodiment 17, wherein the setting sleeve is movable downwardly with the sliding sleeve.

[00039] Embodiment 19. The downhole tool of any of embodiments 16-18, wherein the upper anti-extrusion element has a portion thereof that extends into a space between the setting sleeve and the tubular body.

[00040] Embodiment 20. The downhole tool of any of embodiments 16-19, further comprising a plurality of lock rings movable with the setting sleeve and receivable in grooves in the tubular body in the second position of the setting sleeve.

[00041] Therefore, the apparatus, methods, and systems of the present disclosure are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is, therefore, evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure.

[00042] As used herein, the words “comprise,” “have,” “include,” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps. While compositions, systems, and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions, systems, and methods also can “consist essentially of’ or “consist of’ the various components and steps. It should also be understood that, as used herein, “first,” “second,” and “third,” are assigned arbitrarily and are merely intended to differentiate between two or more cement compositions, flow ports, etc., as the case may be, and does not indicate any sequence. Furthermore, it is to be understood that the mere use of the word “first” does not require that there be any “second,” and the mere use of the word “second” does not require that there be any “third,” etc.

[00043] Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a - b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.