Patent Application
20240328272
In the oil and gas industry, hydrocarbon fluids are commonly found in hydrocarbon reservoirs. These hydrocarbon reservoirs are located far below the surface of the earth in porous rock formations. In order to access the hydrocarbon fluids, wells are drilled into the formations. While drilling the well or during daily operations of the well, equipment or junk often becomes lost or lodged within the well and is referred to as a fish.
Typically, regular drill bits cannot drill through fish. Should a fish fall into a well, a “fishing job” is required to remove the fish from the well, or otherwise clear the well of the fish. Common fishing jobs include pulling the fish out of the well by operating fishing tools that latch onto the fish or milling the fish to clear the well with the use of high strength milling tools.
When employing fishing tools, most fishing tools are screwed into the end of a fishing string and lowered into the well. The fishing tool may be an overshot, a tool which functions by surrounding the fish and gripping it from the outside. The grip is strong enough to carry the fish up the wellbore to the surface.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In one aspect, embodiments disclosed herein relate to an overshot. The overshot includes a tubular housing including a bore, a first end, and a second end, and configured to transfer a fluid flow through the bore from the first end to the second end. The overshot also includes a rotatable housing extending in a direction of a central axis of the tubular housing, comprising a third end and a fourth end. The rotatable housing is configured to receive the fluid flow at the third end and be driven by the fluid flow to have rotational motion about the central axis. The rotatable housing is also configured to receive a fish at the fourth end and rotate and displace the fish towards the tubular housing. The overshot further includes a gripping mechanism disposed within the bore and configured to receive and engage with the rotated fish. The overshot still further includes a bearing disposed between the tubular housing and the rotatable housing and configured to decouple rotational motion of the rotatable housing and the tubular housing.
In one aspect, embodiments disclosed herein relate to a system. The system includes an overshot including a tubular housing comprising a bore, a first end, and a second end, and configured to transfer a fluid flow through the bore from the first end to the second end. The overshot also includes a rotatable housing extending in a direction of a central axis of the tubular housing, comprising a third end and a fourth end. The rotatable housing is configured to receive the fluid flow at the third end and be driven by the fluid flow to have rotational motion about the central axis. The rotatable housing is also configured to receive a fish at the fourth end and rotate and displace the fish towards the tubular housing. The overshot further includes a gripping mechanism disposed within the bore and configured to receive and engage with the rotated fish. The overshot still further includes a bearing disposed between the tubular housing and the rotatable housing and configured to decouple rotational motion of the rotatable housing and the tubular housing. The system also includes an adapter attached to the first end the tubular housing of the overshot. The system further includes a conduit fluidly connected to the tubular housing in the adapter and configured to movably dispose the overshot in a wellbore.
In one aspect, embodiments disclosed herein relate to a method. The method includes running an overshot into a wellbore connected to a conduit. The method also includes supplying a fluid flow to the overshot through the conduit. The method further includes transferring the fluid flow through a bore of a tubular housing from a first end to a second end. The method still further includes receiving, by a rotatable housing extending in a direction of a central axis of the tubular housing, the fluid flow at a third end. The method also includes driving, by the fluid flow, rotational motion of the rotatable housing about the central axis. The method further includes receiving a fish at a fourth end. The method still further includes rotating and displacing the fish towards the tubular housing. The method also includes receiving and engaging the rotated fish with a gripping mechanism disposed within the bore. The method further includes removing the overshot with the engaged fish from the wellbore.
Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.
In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure 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.
Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.
In the following description of
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a seismic signal” includes reference to one or more of such seismic signals.
Terms such as “approximately,” “substantially,” etc., mean that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
It is to be understood that one or more of the steps shown in the flowcharts may be omitted, repeated, and/or performed in a different order than the order shown. Accordingly, the scope disclosed herein should not be considered limited to the specific arrangement of steps shown in the flowcharts.
In general, disclosed embodiments include systems and methods for removing a fish from a wellbore using a rotatable overshot guide. The techniques discussed in this disclosure allow removing a fish with an unknown position and orientation, and thus, are beneficial in avoiding multiple trial and error fishing runs.
The drillstring (108) is made of several steel drill pipes (109) connected to form a conduit. Situated at the distal end of the conduit is a bottom hole assembly (BHA) (110). The BHA (110) includes a drill bit (112) for cutting into the various formations (104, 106). In addition, the BHA (110) may also include measurement tools that have sensors (160) and hardware to measure downhole drilling parameters, and these measurements may be transmitted to the surface using any suitable telemetry system known in the art. Further, the BHA (110) and the drillstring (108) may include other drilling tools known in the art but not specifically shown.
The drillstring (108) is suspended in the wellbore (102) by a derrick structure (118). Mounted at the top of the derrick structure (118) is a crown block (120). A traveling block (122) hangs down from the crown block (120) via a drilling line (124). Connected to one end of the drilling line (124) is a drawworks (126). The drawworks (126) is a reeling device used to adjust the length of the drilling line (124) so that the traveling block (122) is capable of moving up or down the derrick structure (118). Additionally, the traveling block (122) includes a hook (128) on which a top drive (130) is supported.
The top drive (130) is coupled to the top of the drillstring (108) in order to rotate the drillstring (108). During a drilling operation at the well site (100), subsurface rock is broken by rotating the drillstring (108) relative to the wellbore (102) and applying weight to the drill bit (112). Drilling fluid (often referred to as mud) is stored in a mud pit (132), and at least one pump (134) may pump the mud from the mud pit (132) into the drillstring (108). The mud flows into the drillstring (108) through appropriate flow paths in the top drive (130). Details of the mud flow path have been omitted for simplicity but would be understood by a person skilled in the art.
Here, a control system (199) is disposed at and communicates with the well site (100). The control system (199) controls at least a portion of a drilling operation at the well site (100) by providing commands to various components of the drilling operation. The control system (199) is capable of receiving data from one or more sensors (160) arranged to measure controllable parameters of the drilling operation. Sensors (160) may be arranged to measure WOB (weight on bit), RPM (drillstring (108) rotational speed), GPM (flow rate of the mud pumps (134)), ROP (rate of penetration of the drilling operation), and other measurements that might be appropriate and understood by a person skilled in the art.
While drilling the wellbore (102), as described above, various pieces of equipment may become disconnected or fall from the surface portion of the well site (100) (surface portion being on or above the surface of the Earth) and become lost in the downhole portion of the well site (100) (downhole portion being anywhere beneath the surface of the Earth). Equipment, junk, or any object that is lost, lodged or malfunctioning downhole is called a fish (140). Commonly, a fish (140) originates from a drilling operation as described above, such as the drill bit (112) or a portion of the drillstring (108), but may be any other operation equipment without departing from the scope of this disclosure.
The fish (140) may be fished or drilled out to clear the well for production and/or continuing operations. Fishing tools may come in the form of spears or overshots. Spears enter the fish to grasp it from the inside, and overshots pass over the outside of the fish to grasp the fish from the outside. For a fishing job to be successful, the fishing tool that is run downhole engages an accessible portion of the fish (140), with enough force to pull the fish (140) out of the wellbore (102). However, in many instances, the fish (140) is positioned against a wall of the wellbore (102), or otherwise in an unknown orientation, such that engaging the fish (140) is difficult, and oftentimes requires multiple trial and error runs. Multiples runs during a fishing job may result in additional costs, in both time and money. Therefore, a fishing tool that can successfully remove or otherwise clear the well of the fish (140), in a single run, regardless of the position of the fish (140) may be beneficial.
The conduit (203) is positioned within the wellbore (102) so that the overshot (201) can be movably disposed in the wellbore (102) and engage the fish (140). In some embodiments, the conduit (203) may have a tubular body for passage of fluid and may be connected to a pump (134). The conduit (203) may be fluidly connected to the overshot (201) in the adapter (205), allowing fluid to flow from the pump (134) into the overshot (201). The fluid may be any conventionally known drilling fluid, such as water-based muds, oil-based muds, and gaseous fluid, and may include additives to facilitate freeing of a fish from a stuck position.
Furthermore, the overshot (201) may include a guide (207) and a gripping mechanism (209) for assisting in engaging the fish (140). The gripping mechanism (209) may be any type of mechanism or means to grip an outer diameter of a fish (140). The guide (207) receives and guides the fish (140) into the gripping mechanism (209) and may also prevent the fish that is too big from entering the gripping mechanism (209). In many cases, the orientation of the fish (140) with respect to the central axis (239) of the overshot (201) is unknown, and the guide (207) might not receive the top or any portion of the fish (140). In some embodiments, a fluid flow is provided to induce rotational motion of the guide (207) about the central axis (239). The rotational motion of the guide (207) may assist in changing the orientation of the fish (140), and thus facilitating the guiding of the fish (140) into the gripping mechanism (209).
Disposed at a first end (310) of the tubular housing (302) is a threaded connection (320) that connects the overshot (300) to the adapter (205). The threaded connection (320) attaches to the exterior of the adapter (205) in the embodiment of
A gripping mechanism (209) is disposed within the bore (308) of the tubular housing (302). The gripping mechanism (209) receives and engages the fish (140) that has been rotated. The gripping mechanism (209) may be for example, a grapple, or any other means to secure the top of the fish (219) within the overshot (201). In some embodiments a gripping mechanism (209) such as a spiral grapple having a central opening to receive the fish (140), may grip the top of the fish (219) by rotating over the fish (140) in a specific direction. Furthermore, upon application of an upward pull load, the gripping mechanism (209) may bite into the fish (140) to form a grip that may allow to pull the fish (140) from the wellbore (102).
At a second end (312) of the tubular housing (302), the tubular housing (302) is connected to the rotatable housing (306) through a bearing (322). The bearing (322) is disposed to attach the tubular housing (302) to the rotatable housing (306) and to decouple the rotational motion (360) of the rotatable housing (306) and the tubular housing (302). Therefore, the rotational motion (360) of the rotatable housing (306) is not transferred to the tubular housing (302).
In accordance with one or more embodiments, rotational motion (360) of the rotatable housing (306) is induced by the interaction of the fluid flow (350) with a plurality of blades (324) attached to an interior surface (326) of the rotatable housing (306). The plurality of the blades (324) may be positioned so that when subjected to the passage of the fluid flow (350) the plurality of blades (324) are displaced in rotational motion (360) about the central axis (239). Furthermore, the plurality of blades (324) may be disposed in a position that further assists the rotation of the fish (140). Specifically, during rotational motion (360) the plurality of blades (324) may form a first opening towards the third end (314) and a second opening towards the fourth end (316) of the rotatable housing (306). In some embodiments, the second opening may be larger than the first opening.
The plurality of blades (324) may be flexibly or rigidly connected to the rotatable housing (306). As a non-limiting example, each of the plurality of blades (324) may be connected to the rotatable housing (306) with one or more springs (328), as shown in
Panel 420 depicts the guide (207) making contact with the fish (140) at the fourth end (316) of the overshot (201). Fluid flow (350) may be pumped through the conduit (203) to interact with the plurality of blades (324) and induce rotational motion (360) of the rotatable housing (306). The rotational motion (360) of the rotatable housing (306) may rotate the body of the fish (140) and guide it towards the gripping mechanism (209). Panel 430 depicts the guide (207) swallowing and guiding the fish (140). The fish (140) may be rotated and may enter the rotatable housing (306) through the second opening formed by the blades (324).
Panel 440 illustrates that by continuing the lowering of the fishing assembly (200) the fish (140) may traverse the first opening formed by the plurality of blades (324) and may enter the tubular housing (302). At the tubular housing (302) the gripping mechanism (209) may engage and secure the fish (140) within the overshot (201). At this point, pumping of the fluid flow (350) into the conduit (203) may be stopped. Panel (450) shows the fish (140) being freed and pulled out of the wellbore (102) with the fishing assembly (200).
In Block 500, an overshot (201) is run into a wellbore (102) connected to a conduit (203). The overshot (201) may be previously connected to the conduit (203) via the adapter (205) attached to the first end (310) of the tubular housing (302). As the overshot (201) approaches the fish (140), the approach speed of the overshot (201) and fishing assembly (200) slows down so that a collision does not occur between the overshot (201) and the fish (140). Specifically, in one or more embodiments, an operator or the control system (199) on the surface monitors the distance between the overshot (201) and the fish (140) and controls the speed of approach of the overshot by regulating the drawworks (126) based on the distance information.
In Block 510, a fluid flow (350) is supplied to the overshot through the conduit (203). A pump (134) may be operated to supply the fluid flow (350) into the conduit (203). Before operating the pump, an operator or the control system (199) on the surface may determine if the overshot (201) is in contact with the fish (140). In Block 520, the fluid flow (350) is transferred through a bore (308) of a tubular housing (302) from a first end (310) to a second end (312).
In Block 530, the fluid flow (350) is received at a third end (314) by a rotatable housing (306) extending in a direction of a central axis (239) of the tubular housing (302). Then, rotational motion (360) of the rotatable housing (306) about the central axis (239) is driven by the fluid flow (350), as shown in Block 540. In some embodiments, driving rotational motion (360) of the rotatable housing (306) may include the fluid flow (350) displacing a plurality of blades (324) in rotational motion (360) about the central axis (239). Each of the plurality of blades (324) may be attached to an interior surface (326) of the rotatable housing (306).
In Block 550, a fish (140) is received at a fourth end (316). The fish (140) is rotated and displaced towards the tubular housing (302), as shown in Block 560. The fish (140) may be displaced by passing a top of the fish (219) from a second opening to a first opening, where the first and second openings are formed by the rotational motion (360) of the plurality of blades (324). In some embodiments, the second opening is larger than the first opening, in order to assist guiding the fish (140) towards the tubular housing (302).
In Block 570, the rotated fish is received and engaged with a gripping mechanism (209) disposed within the bore (308). The fish (140) may be received and gripped by, for example, a grapple disposed within the bore (308) of the tubular housing (302).
In Block 580, the overshot (201) with the engaged fish is removed from the wellbore (102). The fishing assembly (200) may retract towards the surface, raising both the overshot (201) and the fish (140). The fishing assembly (200) may travel upwards with the fish (140) secured in the overshot (201) until the surface is reached. The fish (140) is then removed from the overshot (201) and the wellbore (102).
Accordingly, the aforementioned embodiments as disclosed relate to devices and methods useful for removing a fish (140) from a wellbore (102) in a single fishing trip, even when the position and orientation of the fish (140) are unknown. The disclosed system and methods of removing a fish (140) from a wellbore (102) advantageously eliminates both the need of multiple fishing runs. This benefit, in turn, advantageously increases the rate of success and reduces additional rig time and associated costs.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
