Patent Description:
The handling and supporting of tubular pipe strings has traditionally been performed with the aid of wedge shaped members known as slips. In some instances, these members operate in a tubular gripping apparatus, such as an elevator or a spider. Typically, an elevator or a spider includes a plurality of slips circumferentially surrounding the exterior of the pipe string. The slips are disposed in a housing. The inner sides of the slips usually carry teeth formed on hard metal dies for engaging the pipe string. The exterior surface of the slips and the interior surface of the housing have opposing engaging surfaces which are inclined and downwardly converging. The inclined surfaces allow the slip to move vertically and radially relative to the housing. In effect, the inclined surfaces serve as wedging surfaces for engaging the slip with the pipe. Thus, when the weight of the pipe is transferred to the slips, the slips will move downward with respect to the housing. As the slips move downward along the inclined surfaces, the inclined surfaces urge the slips to move radially inward to engage the pipe. In this respect, this feature of the spider is referred to as "self tightening / wedging effect. " Further, the slips are designed to prohibit release of the pipe string until the pipe load is supported and lifted by another device.

In the makeup or breakup of pipe strings, the spider is typically used for securing the pipe string in the wellbore at a rig floor. Additionally, an elevator suspended from a rig hook includes a separately operable set of slips and is used in tandem with the spider. The elevator may include a self-tightening feature similar to the one in the spider. In operation, the spider holds the tubular string at an axial position while the elevator positions a new pipe section above the pipe string for connection. It is common to install centralizers on the pipe string to help centralize once the pipe string is in the wellbore. After completing the connection, the elevator pulls up on and bears the weight of the string thereby releasing the pipe string from the slips of the spider there below. The elevator then lowers the pipe string into the wellbore. Before the pipe string is released from the elevator, the slips of the spider are allowed to engage the pipe string again to support the pipe string. After the weight of the pipe string is switched back to the spider, the elevator releases the pipe string and continues the makeup or break out process for the next joint.

As the tubular string is run-in to the wellbore, the pipe string or the centralizers on the pipe string may contact the slips even though the slips are retracted. In some instances, the contact between the pipe string and the slips causes damage to the pipe string, the slips, or both.

There is a need, therefore, for apparatus and methods of protecting these components during a tubular running operation.

In one embodiment, a tubular gripping apparatus includes a housing having a bore and a plurality of gripping members movable between a gripping position and a release position. The apparatus may also include a shield having a tubular inner body movable relative to an outer body. The tubular inner body is movable between a retracted position, in which the tubular inner body is positioned above the plurality of gripping members, and an extended position, in which the inner body is at least partially positioned interiorly of the plurality of gripping members.

In another embodiment, a method of running a tubular using a tubular gripping apparatus includes moving a plurality of gripping members of the tubular gripping apparatus to a release position. The tubular gripping apparatus has a shield having an inner body movable relative to an outer body. The method also includes lowering the inner body to an extended position interior of the plurality of gripping members in the release position and lowering the tubular into the tubular position while the elevator positions a new pipe section above the pipe string for connection. It is common to install centralizers on the pipe string to help centralize once the pipe string is in the wellbore. After completing the connection, the elevator pulls up on and bears the weight of the string thereby releasing the pipe string from the slips of the spider there below. The elevator then lowers the pipe string into the wellbore. Before the pipe string is released from the elevator, the slips of the spider are allowed to engage the pipe string again to support the pipe string. After the weight of the pipe string is switched back to the spider, the elevator releases the pipe string and continues the makeup or break out process for the next joint.

<CIT> describes a tubular member guide. The apparatus includes a bore with a longitudinal axis extending therethrough and configured to support a tubular member. The apparatus has first and second openings in its sides, and an inner wall extending from the first to the second opening. The apparatus further includes a first guiding member adjacent the first opening and a second guiding member adjacent the second opening.

<CIT> describes a power operated slip assembly for supporting a well pipe in a rotary table. The slips are interconnected for movement vertically in unison by a series of shafts turning about different horizontal axes. The shafts are interconnected by an angle drive arrangement for rotation in unison.

<CIT> describes an apparatus for connecting a tubular. The apparatus includes a drill rig elevator with a rotatable set of slips. As a result, the elevator can grip the tubular to pick up and position the tubular and can continue to grip the tubular as the tubular is rotated to be threaded to a tubular string in a well bore. The slips can also be moved axially to compensate for movement of the tubular toward the tubular string as the tubular is threaded to the tubular string.

<CIT> describes an apparatus for supporting a tubular that evenly distributes stress along the contact length of a tubular. The apparatus includes a bowl having a longitudinal opening extending therethrough and an inner surface for receiving a gripping member. The gripping member is movable along the surface of the bowl for engaging the tubular. The apparatus is configured so that an upper portion of the gripping member will engage the tubular before the rest of the gripping member engages the tubular.

In another embodiment, a method of running a tubular using a tubular gripping apparatus includes moving a plurality of gripping members of the tubular gripping apparatus to a release position. The tubular gripping apparatus has a shield having an inner body movable relative to an outer body. The method also includes lowering the inner body to an extended position interior of the plurality of gripping members in the release position and lowering the tubular into the tubular gripping apparatus. The method further includes raising the inner body to a retracted position above the plurality of gripping members and moving the plurality of gripping members to a gripping position to retain the tubular in the tubular gripping apparatus.

<FIG> is a perspective view of an exemplary tubular gripping apparatus, according to embodiments of the present disclosure. As shown, the tubular gripping apparatus is a spider <NUM> suitable for use with a rotary table (not shown). Alternatively, the spider <NUM> may be fitted for use with an elevator or a top drive casing make up system. <FIG> is a cross-sectional view of the spider <NUM> of <FIG> in which the slips are closed. <FIG> and <FIG> are top and bottom views, respectively, of the spider <NUM> of <FIG>. <FIG> is a cross-sectional view of the spider <NUM> of <FIG> in which the slips are open.

The spider <NUM> includes a housing <NUM> for housing one or more gripping members, such as slips <NUM>, a cover assembly <NUM>, and a shield <NUM>. The housing <NUM> of the spider <NUM> is formed by pivotally coupling two sections 25a,b using one or more connectors, preferably hinges <NUM> formed on both sides of each body section, to couple the two body sections together. The housing <NUM> includes a bore extending therethrough. Alternatively, the housing sections 25a,b may be hinged on one side and selectively locked together on the other side. A hole is formed through each hinge <NUM> to accommodate a pin <NUM> to couple the housing sections 25a,b together.

In one embodiment, the slips <NUM> are attached to a carrier <NUM>, as shown in <FIG>. The carrier <NUM> is movable in a groove <NUM> formed in the housing <NUM>, as shown in <FIG>. For example, the back of the slips <NUM> is attached to the interior surface of the carrier <NUM>. The exterior surface of the carrier <NUM> has an inclined surface that is complementary to the inclined surface <NUM> of the housing <NUM>. In one embodiment, the carrier <NUM> may include a guide member for guiding movement of the slip <NUM> relative to the housing <NUM>. For example, the carrier <NUM> can include an inclined shoulder <NUM> (shown in <FIG> and <FIG>) formed on the exterior of each side wall of the carrier <NUM>, and the housing <NUM> can include side plates <NUM>, shown in <FIG> and <FIG>. The inclined shoulder <NUM> engages the lower end of the side plates <NUM> and moves along the side plates <NUM> as the slips <NUM> are moved relative to the housing <NUM>. In this manner, the guide member may maintain the path of a moving slip <NUM> along the inclined surface <NUM> of the housing <NUM>. Alternatively, the carrier <NUM> and/or slip <NUM> can be coupled to the housing <NUM> using a pin and a guide slot connection. In another embodiment, the carrier <NUM> may be coupled to the housing <NUM> using a dovetail connection. Because the carrier <NUM> engages the housing <NUM>, the carrier <NUM> allows the slips <NUM> to be exchanged more easily in response to changes in pipe sizes or damage to the slips <NUM>. It is contemplated use of the carrier <NUM> can be optional in the embodiments described herein such that the back of the slips <NUM> has the inclined surface for engaging the inclined surface of the housing <NUM>. Dies <NUM> having teeth may be disposed on the interior surface of the slips <NUM> for engaging the tubular. <FIG> and <FIG> show eight slips <NUM> coupled to the body sections 25a,b of the spider <NUM>. It contemplated the spider <NUM> may have a total of two or more slips <NUM>, such as four, six, eight, ten, or twelve slips <NUM>.

The spider <NUM> includes a leveling ring <NUM> for coupling the slips <NUM> together and synchronizing their vertical movement. The leveling ring <NUM> may include two sections coupled together. Each ring section is coupled to one of the housing sections 25a,b such that the leveling ring <NUM> can open and close with the housing <NUM>. The slips <NUM> are pivotally coupled to a lower portion of the leveling ring <NUM>. In some embodiments, a pivot arm <NUM> is connected between the leveling ring <NUM> and the carrier <NUM>. The leveling ring <NUM> and the carrier <NUM> are pivotally connected to opposite ends of the pivot arm <NUM>. Examples of the pivot arm <NUM> include a straight arm, an "L" shape arm, or other suitable configuration. The pivot arm <NUM> allows the carrier <NUM> and the slips <NUM> to move radially outward and upward along the inclined surface <NUM> of the housing <NUM> as the leveling ring <NUM> moves upward relative to the housing <NUM>. It is contemplated the slips <NUM> can be coupled to the pivot arm <NUM> such that use of the carrier <NUM> is optional.

A plurality of cylinders <NUM> are used to move the leveling ring <NUM> vertically relative to the housing <NUM>. As shown in <FIG>, three cylinders <NUM> are coupled to each section of the leveling ring <NUM>. Although any suitable number of cylinders <NUM> may be used, such as one, two, four, five, or more. The cylinder <NUM> is attached to the lower portion of the housing <NUM>, and the upper end of its piston rod <NUM> is attached to the leveling ring <NUM>. In some embodiments, an optional ring connector <NUM> is used to couple the leveling ring <NUM> to the piston rod <NUM>. In one example, the ring connector <NUM> includes side flanges <NUM> attached to the leveling ring <NUM> and a tubular body <NUM> disposed around the piston rod <NUM>. <FIG> shows the piston rod <NUM> retracted in the cylinder <NUM>, and the leveling ring <NUM> in a lower position. In this position, the slips <NUM> are in a gripping position, also referred to as a closed position. Extension of the piston rod <NUM> will move the leveling ring <NUM> to an upper position. In turn, the slips <NUM> are moved upward and radially outward along the inclined surface <NUM> of the housing <NUM> to a release position, also referred to as an open position. In some embodiments, one or more sensors are used to detect the position of the slips <NUM>. For example, a weight sensor <NUM> can be installed on the inclined surface <NUM> of the housing <NUM>. The weight sensor <NUM> is configured to detect a contact member <NUM> that is biased by a spring. The contact member <NUM> is depressed by a slip <NUM> as the slip <NUM> travels down the inclined surface <NUM> of the housing <NUM>. When depressed, the contact member <NUM> can be detected by the weight sensor <NUM>. In turn, the weight sensor <NUM> will send a signal indicating the slips <NUM> are in the closed position. An exemplary weight sensor is a proximity sensor configured to detect the contact member such as a Namur proximity sensor. Another example of a weight sensor is a hydraulic sensor such as a cam valve sensor.

The cover assembly <NUM> includes two separate sections, each attached above a respective housing section 25a,b. The sectioned cover assembly <NUM> allows the housing sections 25a,b of the spider <NUM> to open and close without removing the cover assembly <NUM>. The sections of the cover assembly <NUM> form a hole to accommodate the pipe string and the centralizers.

In some embodiments, the spider <NUM> includes a shield for protecting the slips <NUM>. <FIG> show an exemplary embodiment of the shield <NUM>. The shield <NUM> includes an inner tubular body <NUM> disposed in an outer body <NUM> and movably coupled to the outer tubular body <NUM>. <FIG> and <FIG> are different views of the inner body <NUM> in a retracted position relative to the outer body <NUM>. <FIG> is a top view of <FIG>. <FIG> and <FIG> are different views of the inner body <NUM> in an extended position relative to the outer body <NUM>. The shield <NUM> is disposed inside the spider <NUM> and the bore of the shield <NUM> is preferably concentric with the bore in the spider <NUM>. The outer body <NUM> includes a flange <NUM> for attachment to the spider <NUM>. As shown in <FIG>, the flange <NUM> is attached to the cover assembly <NUM> of the spider <NUM>. In some embodiments, each of the inner body <NUM> and the outer body <NUM> includes two sections that are coupled together to form the tubular shaped bodies <NUM>, <NUM>. Each section of the bodies <NUM>, <NUM> are attached to a respective section of the cover assembly <NUM> and can open and close with the spider <NUM>.

The shield <NUM> includes two cylinders <NUM> for moving the inner body <NUM> axially relative to the outer body <NUM>. As shown in <FIG> and <FIG>, the cylinders <NUM> are attached to the flange <NUM>. The piston rod <NUM> of the cylinders <NUM> is attached to a lower portion of the inner body <NUM> and below the outer body <NUM>. Each piston rod <NUM> is attached to one section of the inner body <NUM>. Although two cylinders <NUM> are shown, it is contemplated one or more cylinders <NUM> may be used, such as one, three, four, five, or six cylinders. The cylinders <NUM> may be actuated using hydraulics, pneumatics, or electric. The piston rod <NUM> and the inner body <NUM> are shown in the retracted position. In this position, the inner body <NUM> is retracted above the slips <NUM>, as shown in <FIG>. Extension of the piston rod <NUM> will lower the inner body <NUM> to the extended position, as shown in <FIG> and <FIG>. In the extended position, the inner body <NUM> will be at least partially positioned inside the plurality of slips <NUM>. <FIG> shows the inner body <NUM> in the extended position, and the slips <NUM> are disposed around the exterior of the inner body <NUM>. In this manner, the inner body <NUM> can protect the slips <NUM> from contact with the tubular string or other tools being run into or out of the wellbore. The extended inner body <NUM> of the shield <NUM> is configured to extend into overlapping position with at least a majority portion of the length of the slips <NUM>, such as seventy percent, eighty percent, or ninety percent or more of the length of the slips <NUM>. In one embodiment, the inner body <NUM> protects the entire length of the slips <NUM>. It is contemplated that other suitable actuators for moving the inner body <NUM> may be used, for example, a rack and pinion mechanism.

A plurality of guide bearings <NUM> are provided between the inner body <NUM> and the outer body <NUM> to facilitate movement of the inner body <NUM>. In some embodiments, the guide bearings <NUM> are longitudinal rectangular bars attached to the exterior of the inner body <NUM>. Each guide bearing <NUM> is movable in a channel <NUM> formed on the interior surface of the outer body <NUM>. As shown, two guide bearings <NUM> are attached to each section of the inner body <NUM>. It is noted that any suitable number of guide bearings <NUM> may be used, such as one, three, four, or five guide bearings. Also, it is contemplated that one or more of the guide bearings <NUM> may be attached to the interior of the outer body <NUM>, and the respective channels <NUM> may be formed on the exterior surface of the inner body <NUM>. Stop members <NUM> may be attached to the housing <NUM> to limit the downward movement of the inner body <NUM>. The stop members <NUM> may engage the lower end of the guide bearings <NUM> and act as a lower limit for the guide bearings <NUM>. Although each guide bearing <NUM> is shown with a respective stop member <NUM>, it is contemplated the number of stop members <NUM> may be less than the number of guide bearings <NUM>, such as one, two, or three stop members <NUM>.

The shield <NUM> may include one or more sensors <NUM>, <NUM> for indicating the position of the inner body <NUM> relative to the outer body <NUM>. A first sensor <NUM> is used to indicate the inner body <NUM> is in the retracted position, and a second sensor <NUM> is used to indicate the inner body <NUM> is in the extended position. For example, the first sensor <NUM> can be attached to the flange <NUM>, and the second sensor <NUM> can be attached to the lower portion of the outer body <NUM>. In some embodiments, the sensors <NUM>, <NUM> may be used to control movement of the inner body <NUM>, such as stopping the inner body <NUM>. Exemplary sensors <NUM>, <NUM> may be proximity sensors selected from capacitive, inductive, photoelectric, magnetic, or ultrasonic type proximity sensors. In one example, the sensors <NUM>, <NUM> are NAMUR proximity sensors. In some embodiments, suitable hydraulic sensors such as cam valve sensors can be used. The sensors <NUM>, <NUM> are configured to detect a target <NUM>, shown in <FIG>, disposed on the inner body <NUM>. The target <NUM> can move in a target slot <NUM>, shown in <FIG>, formed on the interior surface of the outer body <NUM>. The target <NUM> is positioned on the inner body <NUM> such that it can be read by the first sensor <NUM> when the inner body <NUM> has reached the retracted position and by the second sensor <NUM> when the inner body <NUM> has reached the extended position.

In operation, an exemplary spider <NUM> equipped with a shield <NUM> may be used in a tubular running operation involving making up or breaking out one or more tubulars. <FIG> shows the slips <NUM> of the spider <NUM> in the closed position. In this position, the spider <NUM> is gripping a tubular string <NUM> in the wellbore. The weight sensor <NUM> is activated to indicate the slips <NUM> are in the closed position. The inner body <NUM> of the shield <NUM> is in the retracted position, in which the inner body <NUM> is raised above the slips <NUM>.

A top drive casing make up tool may be used to make up a new joint of tubular to the tubular string <NUM>. The casing make up tool may grab a new tubular joint and connect the tubular joint to the tubular string <NUM>. After making up the tubulars and with the casing make up tool still retaining the new joint, a signal can be sent to open the slips <NUM>. The slip cylinder <NUM> is activated to extend the piston rod <NUM> and raise the leveling ring <NUM>. Upward movement of the leveling ring <NUM> causes the slips <NUM> to move upward and radially outward along the inclined surface <NUM> of the housing <NUM> toward the release position. After the slips <NUM> move up the inclined surface <NUM>, the spring biases the contact member <NUM> outward, which indicates the slips <NUM> are no longer in the closed position. It is noted the leveling ring <NUM>, optionally, has an inner diameter that is larger than the outer diameter of the outer body <NUM> so that the leveling ring <NUM> can be positioned around the outer body <NUM>.

A signal is sent to activate the shield <NUM>. The piston rods <NUM> attached to the inner body <NUM> are extended to lower the inner body <NUM>. The inner body <NUM> is lowered to a position inside of the surrounding slips <NUM>. As shown in <FIG>, the inner body <NUM> has been extended downward to fully protect the slips <NUM> from contact with the tubular string <NUM>. The slips <NUM> are positioned around the exterior of the inner body <NUM> and protected from contact with the tubular string <NUM> and the centralizers. When the inner body <NUM> reaches the extended position, the second sensor <NUM> will detect the target <NUM> on the inner body <NUM>. In turn, the second proximity sensors <NUM> will send a signal indicating the inner body <NUM> has reached the extended position. In this position, the lower end of the guide bearings <NUM> may engage the stop members <NUM>. See <FIG> and <FIG>.

The top drive casing make up tool is now allowed to lower the extended tubular string <NUM> through the spider <NUM>. The shield <NUM> will prevent the tubular string <NUM> and any centralizers on the tubular string <NUM> from contacting the slips <NUM>.

After lowering the tubular string <NUM>, the shield <NUM> is deactivated by retracting the inner body <NUM>. The inner body <NUM> is raise until the upper, first sensor <NUM> detects the target <NUM> on the inner body <NUM>. See <FIG> and <FIG>.

Thereafter, a signal is sent to activate the slips <NUM>. The slips <NUM> are moved downwardly and radially inward along the inclined surface <NUM> toward the tubular string <NUM>. In the closed position, the slips <NUM> will grip the tubular string <NUM> and retains its weight. The slips <NUM> will also depress the contact member <NUM>, thereby causing the weight sensor <NUM> to send a signal indicating the slips <NUM> are in the closed position. The casing make up tool can now release the tubular string <NUM> and used to bring the next tubular joint to be added to the tubular string <NUM>.

In some embodiments, the tubular inner body is in the retracted position, the plurality of gripping members are in the gripping position.

In some embodiments, when the tubular inner body is in the extended position, the plurality of gripping members are in the release position.

In some embodiments, the shield includes a first sensor for detecting the inner body in the retracted position and a second sensor for detecting the inner body in the extended position.

In some embodiments, the shield includes a guide bearing disposed between the tubular inner body and the outer body.

In some embodiments, the shield includes a stop member for limiting downward movement of the guide bearing.

In some embodiments, the outer body includes a flange for attaching to a cover assembly.

In some embodiments, the tubular gripping apparatus includes a weight sensor for detecting the plurality of gripping members in the gripping position.

In some embodiments, the tubular gripping apparatus includes a leveling ring for moving the plurality of gripping members.

In some embodiments, the leveling ring has an inner diameter that is larger than an outer diameter of the outer body.

In some embodiments, the tubular gripping apparatus includes a cylinder for moving the plurality of gripping members, wherein the cylinder is attached to a lower end of the housing, and a piston rod of the cylinder is extended to move the plurality of gripping members to the release position.

In some embodiments, the method includes using a first sensor of the shield to detect the inner body is in the retracted position.

In some embodiments, the method includes using a second sensor of the shield to detect the inner body is in the extended position.

In some embodiments, the method includes moving a guide bearing of the tubular inner body along the outer body.

In some embodiments, the method includes engaging a lower end of the guide bearing with a stop member.

In some embodiments, the method includes using a weight sensor to detect the plurality of gripping members in the gripping position.

In some embodiments, moving the plurality of gripping members includes moving a leveling ring axially relative to the inner body.

In some embodiments, the leveling ring has an inner diameter that is larger than outer diameter of the outer body.

In some embodiments, moving the leveling ring axially includes actuating a cylinder, wherein the cylinder is attached to a lower end of the housing, and a piston rod of the cylinder is extended to move the leveling ring upward relative to the inner body.

Claim 1:
A tubular gripping apparatus (<NUM>), comprising:
a housing (<NUM>) having a bore;
a plurality of gripping members (<NUM>) movable between a gripping position and a release position; and
a shield (<NUM>) having a tubular inner body (<NUM>) movable relative to an outer body (<NUM>), wherein the tubular inner body (<NUM>) is movable between a retracted position, in which the tubular inner body (<NUM>) is positioned above the plurality of gripping members (<NUM>), and an extended position, in which the inner body (<NUM>) is at least partially positioned interiorly of the plurality of gripping members (<NUM>).