Patent Application
20240229568
The present disclosure relates generally to rod lift systems in oil wells and, more particularly, to tooling for enabling rotation and a safety release within a rod lift string.
When installing a rod lift system in an unconventional oil well, a full containment deployment is often required to prevent the loss of hydrocarbons for extraction. To this end, a slickline unit is commonly used to initially deploy the pump which is secured using a rod blow-out preventer (BOP). While the rod BOP will maintain the well in full containment, the engaged rams of the BOP will prevent rotating the pump to apply the required make-up torque while connecting to the rod string above the pump. As such, it may be necessary to use a nonstandard rotation tool between the pump and the rod string to overcome the limitations introduced by the rod BOP.
Moreover, in the event a pump in the rod lift system becomes stuck downhole, the rod string and the tubing string must oftentimes be removed simultaneously to retrieve the pump. The tubing string will be full of liquids (e.g., hydrocarbons), and the rod string must be cut along each tubing joint. This removal process may expose workers to sour gas, such as hydrogen sulfide, and will increase intervention times involved in the correction of the stuck pump.
Accordingly, improvements to rod lift systems are desired to ease installation and extraction, and to reduce intervention times.
Various details of the present disclosure are hereinafter summarized to provide a basic understanding. This summary is not an extensive overview of the disclosure and is neither intended to identify certain elements of the disclosure, nor to delineate the scope thereof. Rather, the primary purpose of this summary is to present some concepts of the disclosure in a simplified form prior to the more detailed description that is presented hereinafter.
According to an embodiment consistent with the present disclosure, a shearable swivel tool for a rod lift system includes an upper coupling section, a lower coupling section operatively coupled to the upper coupling section with one or more shearable members, and a swivel housing operatively coupled to the lower coupling section and housing a swivel mechanism configured to be operatively coupled to a downhole pump of the rod lift system. The one or more shearable members are configured to fail upon assuming a predetermined shear limit resulting from an axial load assumed on the upper coupling section, and the swivel mechanism is rotatable independent of the swivel housing, thereby allowing the downhole pump to rotate independent of the shearable swivel tool.
In a further embodiment, a rod lift system for a well includes a beam pump assembly arranged at a wellhead, production tubing extended into a well extending from the wellhead, a rod string operatively coupled to the beam pump assembly and extendable into the production tubing within the well, a downhole pump operatively coupled to a distal end of the rod string and arranged within the production tubing, and a shearable swivel tool interposing the rod string and the downhole pump. The shearable swivel tool includes an upper coupling section providing a top connector, the distal end of the rod string being secured to the top connector, a lower coupling section operatively coupled to the upper coupling section with one or more shearable members configured to shear upon assuming a predetermined shear limit, and a swivel housing operatively coupled to the lower coupling section and housing a swivel mechanism operatively coupled to the downhole pump and a bottom connector. The predetermined shear limit is reached when the rod string applies a predefined axial load on the upper coupling section at the top connector, and shearing the one or more shearable members allows the upper coupling section to separate from the lower coupling section to retrieve the rod string while the downhole pump remains in the well.
Any combinations of the various embodiments and implementations disclosed herein can be used in a further embodiment, consistent with the disclosure. These and other aspects and features can be appreciated from the following description of certain embodiments presented herein in accordance with the disclosure and the accompanying drawings and claims.
Embodiments of the present disclosure will now be described in detail with reference to the accompanying Figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the claimed subject matter. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. Additionally, it will be apparent to one of ordinary skill in the art that the scale of the elements presented in the accompanying Figures may vary without departing from the scope of the present disclosure.
Embodiments in accordance with the present disclosure generally relate to rod lift systems in oil wells and, more particularly, to tooling for enabling rotation and a safety release within a rod lift string. The embodiments presented herein may prove advantageous in allowing proper operation of rod lift systems in unconventional wells while maintaining optimal safety and maintenance procedures for the rod lift system. The hybrid tool disclosed herein, and the associated rod lift system, may be utilized within unconventional oil/gas wells or any application requiring a full containment deployment for operation.
A rod string 116 may be operatively coupled to the cables 114, and the rod string 116 may be extendable within a completed oil/gas well 122 (hereinafter “the well 122”). The rod string 116 extends through a wellhead 118, which may incorporate a stuffing box 120 designed to allow the rod string 116 to reciprocate within (through) the wellhead 118 while maintaining pressure within the well 122. The wellhead 118 provides a surface cap for the well 122 and serves as an interface between the well 122 and any surface equipment. In some applications, some or all of the well 122 may be lined with casing 124 that separates the well 122 from the surrounding environment. In at least one embodiment, one or more perforations 126 may be defined in the casing 124 to provide a conduit for the entry of hydrocarbons (e.g., oil and gas) into the well 122, thus helping facilitate the extraction of the hydrocarbons by the system 100. The casing 124 may terminate with a casing shoe 128 or the like.
Production tubing 130 may be extended into the well 122 from the wellhead 118 and arranged concentric with the casing 124, thereby defining an annulus 134 between the casing 124 and the production tubing 130. The production tubing 130 provides a conduit to facilitate extraction of the hydrocarbons, and may be held in place within the casing 124 using a tubing anchor 132. Fluids (e.g., hydrocarbons) that migrate into the production tubing 130 may be extracted from the well 122 via a production outlet 136a provided at the wellhead 118. As needed, any fluids (e.g., gases) present within the annulus 134 may also be extracted from the well 122 via a gas outlet 136b provided at the wellhead 118.
Hydrocarbon extraction is initiated and controlled by the operation (motion) of the beam pump assembly 102 at the surface and a downhole pump 138 arranged within the well 122 and, more particularly, within the production tubing 130. The downhole pump 138 may be operatively coupled to a distal end of the rod string 116 and may operate based on the reciprocating motion of the rod string 116, which actuates the pumping mechanism of the downhole pump 138. As the downhole pump 138 operates, hydrocarbons that have migrated into the well 122 from the perforations 126 (or elsewhere) are pulled or drawn through a standing valve 140 and subsequently through a travelling valve 142, which communicates with an interior of the production tubing 130. Once in the production tubing 130, further reciprocation of the rod string 116 causes the downhole pump 138 to continue pumping the extracted hydrocarbons towards the surface within the production tubing 130 and to the production outlet 136a.
During installation of conventional rod lift systems, and especially in systems with high hydrogen sulfide (H2S) content, initial deployment of the downhole pump must be done using a slickline unit to achieve full containment deployment. More particularly, the downhole pump must be secured using a rod blow out preventer (BOP), which operates to maintain the well with full containment, but fully closed BOP rams prevent the downhole pump from being rotated to apply the required make-up torque and connect the rod string above it. Consequently, in prior art systems, it is often required to use a nonstandard tool between the downhole pump and the rod string to facilitate interconnection.
Using non-standard tools is typically not recommended in combination with conventional shear couplings because it can introduce additional axial movement that can harm the entire system performance and potentially lead to premature failure of the entire rod string. In contrast, not having at least a conventional shear coupling installed at the downhole pump can cause a more expensive and dangerous condition while retrieving the production tubing in case of a stuck downhole pump. In such a scenario, the rod string would have to be retrieved along with the production tubing, which will be full of liquids (e.g., hydrocarbons), and it is necessary to cut the rod string with every tubing joint. This process increases intervention times and potentially exposes rig personnel to H2S (sour gas).
According to embodiments of the present disclosure, and to mitigate the above-described issues, the system 100 may further include a shearable swivel tool 144 interposing and operatively coupled to the rod string 116 and the downhole pump 138. As described herein, the shearable swivel tool 144 may be operable to enable independent rotation above and below the shearable swivel tool 144, and may thus enable the connection of the downhole pump 138 to the remainder of the rod string 116 while contained in a full pressure-containment scenario. Further, the shearable swivel tool 144 enables disconnection of the rod string 116 from the downhole pump 138 in the event the downhole pump 138 becomes stuck within the production tubing 130. The ability to disconnect the rod string 116 from the downhole pump 138 may allow for corrective measures to be performed in a safer and less time-consuming manner without additionally endangering the normal operation of the system 100.
The upper coupling section 204a may include or otherwise provide a top connector 208, which provides a location for the rod string 116 (
The upper coupling section 204a may also define an inner chamber 210 sized to extend over and receive a portion of the lower coupling section 204b. More specifically, the lower coupling section 204b may provide and otherwise define an axial extension 212 receivable within the inner chamber 210. The upper and lower coupling sections 204a,b may comprise independent component parts that are operatively and releasably coupled to each other using one or more shearable members 214 (
The shearable members 214 may comprise any type of shearable device designed to shear or otherwise fail upon assuming a predetermined shear limit. Examples of the shearable members 214 include, but are not limited to, shear pins, shear screws, or any combination thereof. Moreover, while three shearable members 214 are depicted in
The shearable members 214 may serve a dual purpose. First, the shearable members 214 may operate to mate (couple) the upper and lower coupling sections 204a,b for downhole use. Second, the shearable members 214 may be configured to shear or otherwise fail upon assuming a predetermined shear limit resulting from the shearable swivel tool 144 assuming a predefined overpull value or axial (tensile) load via the rod string 116 (
Once the rod string 116 and the upper coupling section 204a are removed from the well 122, the production tubing 130, along with the lower coupling section 204b and the attached downhole pump 138, may be extracted from the well. If desired, the shearable swivel tool 144 may be subsequently reconstructed at surface by re-attaching the upper coupling section 204a to the upper coupling section 204a using one or more new shearable members 214. The shearable swivel tool 144 may then be used in future downhole operations, as desired.
Still referring to
In some embodiments, the shearable swivel tool 144 may further include a swivel mechanism 218 rotatably mounted to the swivel housing 206. More specifically, the swivel mechanism 218 may provide a head 220 and a stem 222 extending from the head 220. The head 220 may be sized to be received within the swivel housing 206, and the stem 222 may be configured to extend through an aperture 224 defined in the lower end of the swivel housing 206. In some embodiments, a bottom connector 208b may be provided by and otherwise extend from the swivel mechanism 218 and, more particularly, from the stem 222. The bottom connector 208b provides a location for the shearable swivel tool 144 to be attached to the downhole pump 138 (
The head 220 may be loosely arranged within the swivel housing 206 and otherwise provided with a predetermined clearance, thus allowing the swivel mechanism 218 to rotate (swivel) independent of the swivel housing 206, and without affecting the mating at the threaded engagement 216. Consequently, operatively coupling the downhole pump 138 (
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, for example, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “contains”, “containing”, “includes”, “including,” “comprises”, and/or “comprising,” and variations thereof, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Terms of orientation are used herein merely for purposes of convention and referencing and are not to be construed as limiting. However, it is recognized these terms could be used with reference to an operator or user. Accordingly, no limitations are implied or to be inferred. In addition, the use of ordinal numbers (e.g., first, second, third, etc.) is for distinction and not counting. For example, the use of “third” does not imply there must be a corresponding “first” or “second.” Also, if used herein, the terms “coupled” or “coupled to” or “connected” or “connected to” or “attached” or “attached to” may indicate establishing either a direct or indirect connection, and is not limited to either unless expressly referenced as such.
While the disclosure has described several exemplary embodiments, it will be understood by those skilled in the art that various changes can be made, and equivalents can be substituted for elements thereof, without departing from the spirit and scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation, or material to embodiments of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, or to the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.
