Patent Application
20180112484
Hydrocarbon wells have finite lives. At the end of a useful life of a well, plug and abandonment operations are undertaken to ensure the well remains shut in permanently. Such operations generally include cement plugging the well to a level at which cementing is possible and then employing a well abandonment tool such as a WASP™ well abandonment straddle packer commercially available from Baker Hughes Incorporated to cement casing strings in the well head. The tools work well for their intended purpose. Nevertheless, the art is always interested in improved tools.
A wellhead based well control arrangement including a pressure control head having a gripping element configured to grip an outside surface of a well head and a seal element configured to seal against an inside surface of the same well head, a perforating, packer, and circulation mandrel extending from the pressure control head.
A method for controlling a well at a well head for plugging and abandonment operations including running an arrangement as discussed in the immediately preceding paragraph into engagement with a well head, engaging the gripping element to an outside surface of the wellhead, sealing the seal element to an inside surface of the well head, and setting a packer of the mandrel.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
The FIGURE is a schematic cross section view of a wellhead based well control arrangement.
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to the FIGURE, a wellhead based well control arrangement 10 is illustrated. One of skill in the art will recognize a wellhead 12 and two casing strings 14 and 16 disposed within the wellhead 12 in a conventional way. The arrangement 10 is configured for insertion into and securement with the wellhead 12. It is to be understood that the discussion following relates to a portion of an abandonment operation subsequent to the application of a cement plug in the main ID of the well (located below the portion illustrated in the FIGURE). One of skill in the art will also find somewhat familiar a perforating, packer, and circulation mandrel 18 and an inflatable packer 20 since these look similar to the prior art well abandonment straddle packer. It is to be understood that the invention is not limited to use of an inflatable type packer but rather may also use a noninflatable type packer, if desired. Similarity hereafter however is absent. Illustrated in broken lines only for the purpose of conveying the absence of a component that is common for prior art straddle packers is identified with numeral 22. This would be an inflatable packer in a prior art device but is not used in the present invention.
Integral to the mandrel 18 is a pressure control head 24. The pressure control head 24 includes a gripper element 26 (illustrated as a plurality of elements) that is configured to grip an outside surface 30 of the well head 12 (such as an industry standard H4 connection) and a seal element 28, an annular compression-type seal, (illustrated as a plurality of seal elements) that is configured to seal against an inside surface 32 of the wellhead 12. The seal element 28 creates a pressure seal against the inside surface 32 to contain any pressure that might exist outside either of the casing strings 14 and 16 that may act on the pressure control head 24 following the breaching of the casing strings 14 and 16 for cementing purposes during a plugging and abandonment operation. The seal element also, of course, prevents circulating fluid leakage past the pressure control head 24. Seal element 28 replaces the seal function of the element 22 from prior art devices. The gripper element 26 replaces the ancillary function of the element 22 of the prior art to anchor the arrangement 10 in place within the well head 12. It will be understood that the frictional anchoring capability of the element 22 is relatively lesser while the anchoring capability of gripping element 26 of the present invention is quite robust. By decoupling the sealing function and the anchoring function, both functions have been improved. The gripping element in an embodiment is a ring of material dimensioned and positioned to interact with a groove 27 on the wellhead 12. As noted, one embodiment is configured for engagement with an H4 connection whether that be on the well head 12 itself, or on an ancillary structure such as a Horizontal Christmas Tree, a Vertical Christmas Tree, a blowout preventer stack, a Tubing Head Spool, etc. Some of the examples listed may require a lengthening of the mandrel 18 due to the existence of the additional structure between the well head 12 and the arrangement 10 but otherwise the embodiments are substantially the same.
Through the head 24 and mandrel 18 are a circulation line 34 and a return line 36 having functions identical to the prior art. In use, the arrangement 10 generally follows methods of prior art well abandonment straddle packers such as firing a round of perforating guns to breach a casing; circulating cement into the casing and then perforating another casing and circulating cement in that casing as well. Circulation begins downhole of the inflatable packer 20 and returns to the mandrel 18 uphole of the packer 20. Performance of the arrangement is enhanced over the prior art and accordingly enjoys regulatory approval in jurisdictions where a prior art straddle packer does not.
A well may be plugged and abandoned employing the arrangement 10 by running the arrangement 10 into well head 12 on a control umbilical 38 from surface, engaging the gripping element 26 with the outside surface 30 of the well head 12 and sealing the sealing element 28 to the inside surface 32 of the well head 12 simultaneously. Once the head 24 is secured to the wellhead 12, the inflatable packer 20 is inflated to grow radially into contact with an inside surface 40 of casing 14 to seal therewith. Hereafter use of the arrangement 10 is the same as is the method for using the prior art well abandonment straddle packer.
Set forth below are some embodiments of the foregoing disclosure:
A wellhead based well control arrangement including a pressure control head having a gripping element configured to grip an outside surface of a well head and a seal element configured to seal against an inside surface of the same well head, a perforating, packer, and circulation mandrel extending from the pressure control head.
The arrangement as in any prior embodiment wherein the gripping element is a ring.
The arrangement as in any prior embodiment wherein the gripping element is a plurality of gripping elements.
The arrangement as in any prior embodiment wherein the seal element is an annular compression-type seal.
The arrangement as in any prior embodiment wherein the seal element is a plurality of elements.
The arrangement as in any prior embodiment wherein a packer of the mandrel is inflatable.
The arrangement as in any prior embodiment wherein a packer of the mandrel is noninflatable.
The arrangement as in any prior embodiment wherein the pressure control head and mandrel further include a circulation line running therethrough.
The arrangement as in any prior embodiment wherein the pressure control head and mandrel further include a return line running therethrough.
A method for controlling a well at a well head for plugging and abandonment operations including running an arrangement as in any prior embodiment into engagement with a well head, engaging the gripping element to an outside surface of the wellhead, sealing the seal element to an inside surface of the well head, and setting a packer of the mandrel.
The method as in any prior embodiment wherein the engaging the gripping element is with a groove on an outside surface of the well head.
The method as in any prior embodiment wherein the engaging the gripping element is with an H4 connection.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).
The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.
