Downhole Fish Grabbing Tool

This disclosure relates to subterranean wells, and more specifically to removing objects from subterranean well.

In subsurface well drilling and completion operations, objects (such as a tool, pipe, or fragment or component thereof) fall into, get stuck, or are unintentionally left within a wellbore of a subterranean well. This fallen, stuck, or left object is known as a fish. A fish may have one of a variety of unspecified sizes or shapes and can be, for example, as small around as a wire or have a diameter as large as a drill pipe, and can also vary in terms of its location, position, and orientation within the wellbore. The retrieval of such objects from a wellbore is referred to as fishing.

In certain aspects, a downhole fishing tool includes a main body with a first end and a second end defining a first axis. The main body includes a barrel, a fluid line, multiple fluid ports, multiple fluid conduits, and a compartment. The barrel is arranged between the first end to the second end of the main body. The barrel has an outer surface with a barrel diameter. The fluid line is defined in the main body. The multiple fluid ports are defined in the outer surface of the barrel. The plurality of fluid ports are equally spaced around the outer surface of the barrel. Each port conduit in the multiple port conduit fluidly connects a corresponding fluid port in the plurality of fluid ports to the fluid line of the main body. The compartment is defined between the barrel and the second end of the main body. The main body defines a hole extending from the second end to the compartment and centered on the axis. The tool also includes a hollow cover, an imaging sub-system, and a movable claw. The hollow cover is arranged on the axis and has an inner surface defining an interior space extending from a closed end of the cover to an open end of the cover. At least a portion of the main body is arranged in the interior space. The multiple fluid ports are aligned with the cover. The outer surface of the barrel and the inner surface of the hollow cover define an annular space. The imaging sub-system; the imaging sub-system includes a camera arranged in the compartment of the main body and a transparent, protective shell. An optical lens of the camera is centered on the axis and faces away from the first end of the main body. The transparent, protective shell encloses the camera and fluidically isolates the camera. The movable claw is mounted on the second end of the main body and centered on the axis. The sling hub is slidably mounted to the second end of the main body and is centered on the axis.

Some claws include at least two movable fingers. The claw can be centered on the axis.

In some tools, the main body is configured to be positioned in a wellbore.

In some embodiments, the multiple fluid ports are configured to discharge a cleaning fluid, and in some cases, radially discharge the cleaning fluid.

In some tools, the sling hub is part of the claw.

Some protective shells extend into the hole of the second end of the main body.

In some tools, the movable claw includes multiple arms. Each arm of the multiple arms can include a base connected to the second end of the main body, a clamping finger connected to the base, an elbow joint connecting the base and the clamping finger. The clamping finger can have a connection end and a tipped end. The tipped end can be free and movable relative to the base. Some clamping fingers include a magnet section between the connection end and the tipped end. The connection end of the clamping finger can be connected to the elbow joint. Some sling hubs are arranged between multiple arms. In some embodiments, the multiple arms are arranged equidistant from the axis. In some cases, the second end of the main body includes a face and an edge defining the face. The hole of the second end of the main body can extend through the face. Some arms connect to the face of the second end of the main body, adjacent the edge of the second end of the main body. The base of each arm in the multiple arms can extend parallel to the axis.

In certain aspects, a downhole fishing tool includes a main body, a hollow cover, an imaging sub-system, a movable claw, and a sling hub. The main body has a first end and a second end defining a first axis. The main body also includes a barrel arranged between the first end to the second end of the main body and having an outer surface with a barrel diameter. The main body has multiple fluid ports defined in the outer surface of the barrel and a compartment defined between the barrel and the second end of the main body. The main body defines a hole, centered on the axis, extending from the second end to the compartment. The hollow cover is arranged on the axis and has an inner surface defining an interior space. The inner surface extends from a closed end of the cover to an open end of the cover. The fluid ports are aligned with the cover. The outer surface of the barrel and the inner surface of the hollow cover define an annular space. The imaging sub-system includes a camera arranged in the compartment of the main body and a transparent shell enclosing the camera. An optical lens of the camera is centered on the axis and faces away from the first end of the main body. The transparent shell, encloses the camera and fluidically isolates the camera. The movable claw is mounted on the second end of the main body. The movable claw includes at least two arms. Each arm of the at least two arms has a base connected to the second end of the main body, a clamping finger, and an elbow joint connecting the base and the clamping finger. The clamping finger has a connection end and a tipped end. The tipped end is free and movable relative to the base and the connection is connected to the elbow joint. Each clamping finger also has a magnet section between the connection end and the tipped end. The sling hub is mounted to the second end of the main body and is arranged between the at least two arms.

In some tools, the sling hub is centered on the axis.

Some sling hubs define an aperture that is centered on the axis. The aperture can align with the hole defined in the second end of the main body and can align with the lens of the camera. Some sling hubs also includes a hub body mounted to the second end of the main body; and a contact face oriented away from the main body. The aperture can extend through the hub body and contact face.

In some embodiments, the magnet sections of the at least two fingers are arranged adjacent the connection end of the clamping fingers of the at least two arms.

Some magnet sections of the at least two arms are arranged adjacent to the sling hub.

Some tools also include multiple linkages. Each linkage of multiple linkages can extend from the hub body to a corresponding arm of the at least two arms.

In some cases, the tipped ends of the at least two fingers are separated by a distance of about 1 inch to about 6 inches.

In some claws, the at least two arms are arranged on an edge of the second end of the main body. The at least two fingers can be arranged equally around the edge of the second end of the main body.

The at least two arms can have a length of 5 inches to about 30 inches.

In some tools, at least a portion of the main body is arranged in the interior space of the cover.

In some embodiments, the plurality of fluid ports of the main body are equally spaced around the outer surface of the barrel;

The main body can also include a fluid line defined in the main body and multiple port conduits. Each port conduit in the multiple port conduits can fluidly connect a corresponding fluid port to the fluid line of the main body.

In certain aspects, a method includes imaging, by an imaging sub-system of a downhole fishing tool arranged in a wellbore, the downhole environment of a wellbore, a fishing tool into a wellbore. A movable claw of the fishing tool is in an open position with first diameter. The method also includes identifying a debris item in the wellbore using the imaging sub-system and prompting the claw to move from the open position to a closed position. The movable claw of the fishing tool has a second diameter in the closed position that is less than the first diameter.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

Like reference symbols in the various drawings indicate like elements.

The disclosure relates to downhole fishing system with a fishing device (tool) that can diagnose, retrieve, and remove debris from the wellbore in a single run. The fishing device includes main body housing a imaging sub-system for diagnosing and imaging the wellbore environment downhole of the device. The device can flow a clean, transparent fluid through an annular gap between the main body and a cover to increase the transparency of the surrounding fluid and to clean a protective cover encasing a camera of the imaging sub-system. The imaging sub-system can zoom in or out to generate multiple downhole images for diagnosing whether a fish (e.g., debris, wire, lost tool) exists and whether the fishing device can capture the fish. The fishing tool is deployed using a coiled tubing or E-line. The device also includes a movable claw and slidable sling hub mounted to the downhole end of the main body. The movable claw has an open position and a close position. In the open position, a fish can enter into the claw and contact the sling hub. Once the sling hub contacts the fish the device continues to move downhole and the fish applies a mechanical (uphole) force against the sling hub. The sling hub moves uphole relative to the main body, moving the claw into the closed position to retain the portion of the fish in the claw.

The fishing tool can be used to retain a portion of the fish or a part of the fish inserted into the claw. For example, the fishing tool can engage and remove a tool with a fishing neck by the fishing neck, or may engage and retrieve a fish without a fishing neck (e.g. parted tool, slickline, wire, cable, handheld tool, or tubing), by the portion of the fish inserted into the claw and retained by the claw in the closed position. A power magnet on arms of the claw can latch onto a fish of ferromagnetic or magnetic material (e.g., wires) to further retain a fish in the claw when closing the claw and when removing the claw with the clamped fish. The claw can engage, clamp, and latch fishes with a fish neck or outer dimension of up to 6 inches (e.g., between 1.5 inches and 4 inches). Where the fish is flexible, collapsible, or condensable, some claw can expand from the open position to an expanded position, then to a closed position to capture and compress the flexible fish. Additionally, fishes made from soft or penetrable material (e.g., a sponge or tangle of wires) may also be retrieved using the claw despite all dimensions being greater than the diameter of the claw in the open position. For example, the claw may insert pointed, bladed, or barbed tipped fingers into the fish and move from the open position to the closed position to further clamp the soft fish.

is a front view of a debris retrieval systemfor diagnosing, engaging, and retrieving debris in a single run. The systemincludes a fishing toolconnected to a line(e.g., an E-line or coiled cable) and a fluid sourceconnected to the fishing toolb a fluid conduit. A fluid pumpconveys clean, transparent fluid from the fluid sourceto the tool. Additives can be added to the fluid source by injection into the fluid conduit or fluid source through one or more additive sources. The toolexpels the transparent fluid from the fluid sourceto clean the toolin use and to increase the transparency of fluid in a wellbore casing(e.g., fluid adjacent the tool). The wellbore casingis arranged in a wellboredefined in a formation.

The toolhas an uphole end(first end, proximal end) and a downhole end(second end, distal end). A tool axisis defined by the uphole and downhole ends,of the tool. The casingand the toolare centered on the tool axis. The wellboreis also centered on the tool axis. In this configuration, the toolis arranged concentrically to the casingand the casing is arranged concentrically to the wellbore. The tooltranslates axially along the axisto move uphole or downhole within the casing.

The systemincludes a computer sub-systemoperably connected to the tool. The toolis operable to be controlled by the computer sub-system. The computer sub-system includes a controller, one or more processors, and a non-transitory computer-readable medium storing instructions executable by the one or more processors to perform operations. The operations can include imaging, by the imaging sub-system of the downhole fishing tool arranged in a wellbore, the downhole environment of a wellbore. The operations can also include identifying a debris item (fish) in the wellbore, determining, by the imaging sub-system, that the fish is adjacent the sling hub, and prompting device to move in a first, downhole direction to move the claw of the tool from the open position to a closed position.

is a cross-sectional front view of the downhole fishing toolhaving a main bodyhaving a first end(uphole end, proximal end) and a second end (downhole end, distal end). In some cases, the first end and the second end of the main body defines the tool axis. The main bodyis centered on the tool axis. The main bodyincludes a barrelarranged between the first end and the second endof the main body. The barrelhas an outer surfacewith a barrel diameter d.

The main bodyalso includes multiple (e.g., a plurality, at least two) fluid portsdefined in the outer surfaceof barrel. The fluid portsare spaced equally around the outer surfaceof barreland are equidistant from the toolaxis. the fluid ports can open and close based on prompts from a computer sub-system(). In some cases, the ports are openings). Some ports can be electronically controlled, passively controlled valves (e.g., pressure valves or check valves), and/or any other valves or other fluid control ports. Some ports can include rotatable nozzles that can direct a jet or flow of fluid from the fluid source to a downhole environment, external to the main body or tool (e.g., an environment, or wellbore environment). Each portof the multiple portsare arranged on the surfaceof the barreland convey, discharge, expel, flow, or guide fluid from the fluid source() radially outward from the barrel. In the tool, the radial direction is orthogonal to the tool axis. In some main bodies, the ports may direct fluid at an angle greater than 90 degrees or less than 90 degrees relative to the axis. For example, the ports may be oriented so that fluid (arrows) flows from the port at a 15-, 30-, 45-, or 60-degree angle relative to the tool axis. In some cases, each port has a rotatable, directable nozzle which can be individually oriented to a predetermined angle. The directable nozzles may be oriented at the same angle and direction or may be oriented at a different angle and/or direction.

The main bodyalso includes a fluid line() defined in the main body. The fluid line() fluidly connects the fluid source() to the multiple fluid ports. The main body includes multiple port conduits(e.g., a plurality of port conduits or at least two port conduits). Each port conduitof the multiple port conduitsfluidly connect a corresponding fluid portin multiple fluid portsto the fluid lineof the main body.

The main bodyalso includes (defines) a compartment. The compartmentis arranged between barreland the second end of the main body. In some cases, the compartment is defined in the second end of the main body. A holedefined in the second endof the main bodyextends from a faceof the second endto the compartment. The holemay be empty or may be filled by a transparent material to fluidically isolate the compartment from the wellbore environment. The holeis centered on the tool axis.

The devicehas a hollow covercentered on the axis. The hollow cover can be a cylindrical cover with a circular, oval, or elliptical cross-sectional area. The hollow coverconnects to the lineand extends from the first endof the tool. In some cases, a closed end of the hollow cover forms the first end of the tool. In some cases, the main body extends from and/or forms the first end of the tool. The hollow covercovers a portion or section of the main body(e.g., a majority of the main body). The hollow covercovers the fluid portsdefined in the surfaceof the barrel. In this configuration, the fluid portsproject or discharge a transparent, clean fluidradially. The discharged fluidcontacts the coverand flows downhole towards the second endof the tool.

The toolalso includes an imaging sub-systemfor imaging and diagnosing a fish presence in the wellbore casing. The imaging sub-systemincludes a cameraarranged in the compartmentof the main body. The cameraoptical lenscentered on the axis. The cameraand lensand face away from the first endof the main body. The imaging sub-systemalso includes a transparent shell. The transparent shellencloses the cameraso that the camerais fluidically isolated from the wellbore environment.

A movable clawof the toolis mounted on the second endof the main body. The clawis centered on the tool axis. The claw is axially and rotationally fixed to the main bodyand cover. A sling hubof the tool, for example a hollow cylindrical shaft, is also connected to the second endof the main body. The sling hub is centered on the axisand movable along the axis when receiving a force from a fish. The sling hub may be biased in the open position.

is a cross-sectional view of the tooltaken at the fluid portsof the main body, in a plane orthogonal to the tool axis. In the tool, the fluid ports are arranged at an axial location along the axis and extend radially (e.g., are arranged on a single plane orthogonal to the tool axis). In some tools, the fluid ports may be arranged at different axial locations along the tool axis.

The coverencompass or encircles the main bodyand the main bodyis arranged concentrically within the cover. The coverhas an inner surfaceand an outer surface. The inner surfacedefines an interior space. The interior spaceof the coverextends from a closed end (first end, uphole end, proximal end) of the coverto an open end (second end, downhole end, distal end) of the cover. The cover has a cover diameter de, measured from the inner surface of the cover. The cover, barrel, and first endof the main body are made of or include a first material, for example a low steel alloy. The second endof the main bodyis made of or includes a second material, different from the first material. In some cases, the second material is an optically transparent material that passes light. In some cases, the second material is a high index glass, for example crown glass. Some second ends include a section formed by the second material and another section formed by the first material or by a third material, different from the first and second material.

The barrelof the main bodyhas a diameter d, measured from the outer surfaceof the barrel. At least a portion of the barrelis arranged concentrically within the interior spaceof the cover. The barrel diameter dis less than the cover diameter d. The coveris aligned with the fluid portsso that the inner surfaceof the coverguides the fluid discharged from the fluid ports.

The inner surfaceof the coveris distanced from the outer surfaceof the barrelby a gap of distance d. In this configuration, the outer surfaceof the barrelof the main bodyand the inner surface of the coverdefine an annular space. The annular spaceis fluidically connected to the fluid portsso that fluid flows from the fluid portsthrough the annular space. The gap distance dis equal (d-d)/2 (or the difference between the radius of the barrel and the radius of the cover). In the tool, the gap distance dis also equal to the difference between the distance from the tool axisto the inner surfaceof the coverand the distance from the tool axisto the outer surface of the barrel.

The fluid conduitsextend radially from the fluid line. In some cases, the fluid conduits extend radially and axially (towards the second end of the main body) from the fluid line. The fluid lineand fluid conduitsreceive fluid from the fluid source(). The fluid pump() conveys fluid at a rate of up to about 7 BPM (e.g., about 3BPM to about 5BPM).

are cross-sectional front views of the second endof the toolwith the clawin the open position and closed position, respectively. A portion of the main body, extends from the interior space() of the covertowards the second endof the tool. The second endof the main bodyis not aligned with or covered by the cover.

The second endof the main bodydefines the compartment. The cameraof the imaging sub-systemis arranged in the compartment. The cameraincludes or is attached to a lensconfigured to zoom or magnify the image taken or generated by the camera. The magnified image may be a downhole view of the wellbore casingthrough the holein the second endof the main body.

The imaging sub-systemalso includes the protective shellarranged around the camerato isolate the cameraand/or other electronics from fluid in the wellbore environment. The transparent shell can extend through (into) the holeto block fluid from entering the hole. The shell can also extend into a central aperture of the sling hub. The protective shellforms the second endof the main bodyand is made of a transparent material. The transparent material can be high index glass (e.g., crown glass). In some cases, the transparent shell forms a portion of the second end of the main body.

The movable clawof the toolincludes multiple arms(a plurality of arms, at least one arm, at least two arms). Each armof the multiple armshas a baseextending from and mounted to the second endof the main body. The multiple armsare arranged at or adjacent to the edgeof the second endof the main body. The armsmount or connect to the faceof the second endof the main bodyor are integral with the faceof the main body. The baseof each armextends parallel axially, parallel to the tool axis. in some tools, the base extends at an angle relative to the tool axis, for example 15, 30, or 60 degrees relative to the tool axis. The multiple arms can grip, center, and retain fish in the wellbore. Each armalso includes a clamping fingerconnected to the baseby a jointor hinge. The clamping finger has a connection endand a tipped end. The tipped endis free and movable relative to the baseand together define a finger (claw) diameter d(or distance). The finger diameter dincreases and decreases as the tipped endsof the clamping fingersmove about the joint. The finger diameter dincreases where the tipped endsmove radially from the axisand the finger diameter ddecreases where the tipped endsmove radially towards the axis. The clamping fingersof the multiple armsThe clawof the toolhas four armsarranged equidistant from the axisand equally spaced about the axisto form a square cross section. In some tools, the claw has more than four or less than four arms. For example, some tools have a first arm, a second arm, and a third arm arranged with a triangular cross section.

The arms are made of Forged steel. The clamping fingers may include alloy steel and/or stainless steel forgings. In some cases, the tipped ends of clamping fingers include a resilient material, for example alloy steel and/or stainless steel forgings.

The arms have a length of about 5 inches to about 30 inches. The bases have a length of about 2 inches to about 10 inches. The clamping fingers have a length of about 3 inches to about 20 inches (in). The second end of the main body can extend about 1 in to about 15 in along the axis and have a diameter of about 2 in to about 10 in. The movable claw can be sized (e.g., have dimensions) based on the size of the wellbore and/or anticipated fish type and size.

Each clamping fingerincludes a magnet sectionarranged between the connection endand the tipped end. The magnet sectionincludes at least one magnet. In some tools, the at least one magnet is a power magnet or an electromagnet. The magnet sectionattracts and latches metal objects and ferromagnetic objects to the claw. For example, the magnet section can latch or further engage loose steel materials (e.g., wire or parted steel). The magnet section may be electrically power so that the strength of the magnet increases or decreases as required to latch a fish to the claw. In some cases, a computer sub-systemcontrols the strength or attractive force of the magnet section.

In some cases, the clamping fingers include multiple magnet sections, for example a first magnet section adjacent the joint and a second magnet section or adjacent to the topped end. In some arms, a clamping finger can include multiple magnets spaced intervals along the clamping finger, from the connection end to the tipped end. In some cases, the tipped ends of the clamping fingers include a magnet section for locking or latching the tipped ends of the clamping fingers together in the closed position. In some claws, the clamping fingers include barbs along a length of the fingers to latch a fish to the claw. Some tipped ends are bladed or sharpened to impale or stab a fish, for example a fish with soft material. Some tipped ends are hooked to catch and retain flexible fish (e.g., tangled wires, cables, ropes, cloths). The clamping fingersextend linearly along the axisand terminate a the free, tipped endin a tip. The tipis pointed, however, some tips are rounded, hooked, flat, or lipped. In some cases, the clamping fingers are arced.

The elbow jointincludes a stop(e.g., a lock, block, protrusion, abutment) which prevents the elbow jointfrom flexing past a predetermined angle. In the claw, the predetermined angle is 180 degrees or 0 degrees relative to the axis(e.g., parallel to the tool axis). In some cases, the stop permits limited outward flexing of the clamping finger, for example, 15, 30, 45, or 60 degrees relative to the tool axis. The angle at which the joint or stop prevents outward flexing may be adjustable. For example, the stop angle may be determined by a diameter of the casing to prevent the tipped end of the clamping fingers from engaging and/or sticking onto the wellbore casing. In some cases, the stop angle is determined so that the clamping fingers contact or scrape against the wellbore casing. Dragging the tipped end of the clamping fingers along the casing can scratch or scrape off scale deposited on the inner lining of the wellbore casing. In some cases, the stop angle of the joint is set so that the tipped ends of the clamping fingers run adjacent to the wellbore casing at a known distance to remove or scrape scale that extends into the casing and/or impedes the axial path of the tool as the tool moves downhole in the wellbore.