FIELD OF THE INVENTION

The invention relates to mechanically-operated isolation valves in a wellbore.

BACKGROUND OF THE INVENTION

Safety is paramount in wellbore operations for the workers on a drill rig and for the environment. A drill rig may be placed on a ground surface or on a platform in the ocean, and a drill establishes the wellbore in the earth. Then, casings are cemented in place to separate the wellbore and the surrounding formation. Tubulars extend through the casing to extract resources from the earth. However, in some instances an unstable formation, an erratic downwell pressure, a drifting drill rig in the ocean, or another emergency can cause a catastrophic destruction of the wellbore. This can result in the uncontrolled release of natural resources which can destroy a drill rig, injure workers, and harm the environment.

A blowout preventer is a device typically positioned at a wellhead that can isolate a wellbore during an emergency and prevent the uncontrolled release of natural resources. Blowout preventers come in several varieties. In one example, a ram blowout preventer uses two pistons, one positioned on each side of the wellbore, to drive respective rams into each other in the wellbore to sever and slicklines, cables, and tubulars to isolate the wellbore. In another example, a doughnut-like structure is positioned around the wellbore, and pistons drive the doughnut into the wellbore to isolate the wellbore. Additional systems such as a subsea test tree are an intermediate solution that temporarily isolates the wellbore without using the blowout preventer.

However, these various systems rely on hydraulic power or other systems of power that can be interrupted in extreme environments like a marine environment. Thus, the failure of a power system can lead to the failure of a blowout preventer and/or a subsea test tree and to the harm of workers and the environment.

SUMMARY OF THE INVENTION

It is therefore an aspect of embodiments of the present invention to provide a device, a system, and/or a method to isolate a wellbore using mechanical power and without the engagement of a blowout preventer. Mechanical power is less prone to failure, and mechanical force can easily be transmitted from the drill rig to a downhole location. A shear sub may be positioned over a body of an isolation system, and a force supplied to the shear sub causes the shear sub to detach from the body and rotate a valve from an open position to a closed position to isolate the wellbore without the need for the blowout preventer.

It is one aspect of embodiments of the present invention to provide an isolation system where a shear sub is selectively interconnected to a body via shear screws, and a catch of the shear sub drives an actuator to operate the valve. The actuator can be positioned on an outer surface of the body and selectively interconnected to a valve in the interior volume of the isolation system. Rotation of the actuator causes the valve to rotate between the open position and the closed position. The actuator is positioned in a slot of the shear sub, and the catch defines a portion of the slot. When the shear sub is removed, the catch contacts a protrusion of the actuator to rotate the actuator, and thus, rotate the valve from an open position to a closed position to isolate the wellbore.

It is another aspect of embodiments of the present invention to provide an isolation system that comprises a reentry sub that reattaches to the body after separation of the shear sub to reopen the valve and reopen access to the wellbore. The reentry sub also has a slot that engages the actuator, and the reentry sub has guide features that are positioned in a guide channel of the body to orient the reentry sub and the body to reopen the valve. The guide channel has four orientation zones. First, the reentry sub contacts the body, and then the reentry sub rotates until a guide feature progresses through the first orientation zone, at the end of which the reentry sub and the body are in a first angular orientation. Next, the reentry sub extends longitudinally along the body in the second orientation zone to cover more of the body. In a third orientation zone, the reentry sub rotates relative to the body, and a reentry catch on the reentry sub contacts the protrusion of the actuator to rotate the actuator and rotate the valve to the open position. In the fourth orientation zone, the reentry sub further progresses along the body, and a shear ring on an inner surface of the reentry sub sets into a channel on the outer surface of the body to selectively interconnect the reentry sub to the body.

It is another aspect of embodiments of the present invention to provide an isolation system that may be used in a drill string or work string. Therefore, the isolation system can isolate gases and fluids at a certain point rather than the entire wellbore. In this isolation system, a valve isolates a first enclosed volume and a second enclosed volume. Bleeding valves are operatively interconnected to both enclosed volumes. The primary valve and the bleeding valves can be manually or electronically operated from the outer surface of the isolation system to control the pressures of gases and fluids in the drill string or work string.

One particular embodiment of the present invention is a system for disconnection in a drilling operation, comprising a body having an interior volume and an outer surface, the body having a seal positioned in the interior volume and a valve positioned in the seal, the valve is rotatable between an open position and a closed position, the body having an actuator disposed on the outer surface of the body, and the actuator is interconnected the valve; a shear sub at least partially covering the outer surface of the body, the shear sub having a slot and the actuator of the body is positionable in the slot; and a shearing mechanism selectively interconnects the shear sub to the body and selectively disconnects the shear sub from the body when the shear sub is subjected to a predetermined shear force, wherein when the shear sub selectively disconnects from the body, the shear sub rotates the actuator as the actuator is removed from the slot of the shear sub to rotate the valve from the open position to the closed position.

In various embodiments, a protrusion of the actuator extends from an axis of rotation of the actuator; and a catch of the shear sub extends into the slot of the shear sub, wherein the catch drives the protrusion around the axis of rotation to rotate the actuator, which rotates the valve from the open position to the closed position when the shear sub is selectively disconnected from the body. In some embodiments, the shearing mechanism is a plurality of shear screws arrayed about a longitudinal axis of the body and the shear sub. In various embodiments, a tab is disposed on the outer surface of the body and positioned proximate to the actuator, wherein the tab is deflected when the shear sub is selectively interconnected to the body, and the tab is extended when the shear sub is selectively disconnected from the body to prevent rotation of the actuator and rotation of the valve from the closed position.

In certain embodiments, the shear sub rotates the actuator approximately 90 degrees about an axis of rotation to rotate the valve from the open position to the closed position when the shear sub is selectively disconnected from the body. In various embodiments, a second actuator is disposed on the outer surface of the body, and the second actuator is interconnected to the valve; and a second slot of the shear sub, and the second actuator of the body is positionable in the second slot, wherein when the shear sub is selectively disconnected from the body, the shear sub rotates the second actuator as the second actuator is removed from the second slot to rotate the valve from the open position to the closed position.

In various embodiments, a guide slot is on an outer surface of the body; a reentry sub having a guide feature that is positionable in the guide slot, and the reentry sub comprises a reentry slot; and after the shear sub disconnects from the body, the reentry sub is configured to selectively interconnect to the body, and the actuator is positionable in the reentry slot, and wherein the guide feature in the guide slot orients the reentry sub and the reentry slot to rotate the actuator and rotate the valve from the closed position to the open position. In various embodiments, the guide slot comprises four orientation zones (i) a first orientation zone allows the rotation of the reentry sub relative to the body to align the reentry sub and the body in a first angular orientation; (ii) a second orientation zone allows the reentry sub to progressively cover the body along a longitudinal length of the body; (iii) a third orientation zone allows further rotation of the reentry sub relative to the body to align the reentry sub and the body in a second angular orientation; and (iv) a fourth orientation zone allows the reentry sub to further progressively cover the body along the longitudinal length of the body. In some embodiments, a shear ring is positioned in a channel on an inner surface of the reentry sub; and a channel is disposed on the outer surface of the body, wherein the reentry sub is positioned over the body and the shear ring is positioned in the channel of the body to selectively interconnect the reentry sub and the body.

Another particular embodiment of the present invention is a method for operating an emergency disconnect isolation valve, comprising (i) providing a body having an interior volume, a valve positioned in the interior volume, and an actuator on an outer surface of the body, wherein the actuator is operably interconnected to the valve; (ii) positioning a shear sub over at least part of the outer surface of the body, and positioning the actuator in a slot of the shear sub; (iii) selectively interconnecting the shear sub to the body with a shear mechanism that is configured to shear apart when the shear sub is subjected to a predetermined shear force; (iv) applying the predetermined shear force to the shear sub so that the shear mechanism shears apart and the shear sub disconnects from the body along a longitudinal axis of the body; and (v) rotating, by a catch of the shear sub, the actuator as the shear sub disconnects from the body to rotate the valve of the body from an open position to a closed position.

In some embodiments, the method further comprises (vi) providing a tab on the outer surface of the body and positioning the tab proximate to the actuator; (vii) deflecting the tab by a portion of the shear sub when the shear sub is selectively interconnected to the body; and (viii) extending the tab when the shear sub is selectively disconnected from the body to prevent rotation of the actuator and rotation of the valve from the closed position.

In various embodiments, the method further comprises (ix) providing a protrusion of the actuator that extends from an axis of rotation of the actuator; and (x) contacting the protrusion of the actuator with the catch of the shear sub to rotate the actuator and rotate the valve. In certain embodiments, the method further comprises (xi) providing a guide slot on the outer surface of the body, and providing a guide feature on an inner surface of a reentry sub; (xii) positioning the guide feature in a first orientation zone of the guide slot and rotating the reentry sub to a first angular orientation with respect to the body; (xiii) extending the guide feature in a second orientation zone of the guide slot to cover a portion of the body with the reentry sub along a longitudinal length of the body; and (xiv) positioning the guide feature in a third orientation zone of the guide slot and rotating the reentry sub to a second angular orientation with respect to the body so that the catch of the reentry sub rotates the actuator and rotates the valve from the closed position to the open position.

In various embodiments, the method further comprises (xv) providing a channel on the inner surface of the reentry sub and a shear ring in the channel; (xvi) extending the guide feature in a fourth orientation zone of the guide slot to cover a further portion of the body with the reentry sub along the longitudinal length of the body to set the shear ring in a channel on the outer surface of the body to selectively interconnect the reentry sub and the body. In some embodiments, the method further comprises (xvii) re-deflecting the tab by a portion of a reentry sub when the reentry sub covers a portion of the body along a longitudinal length of the body. In certain embodiments, the method further comprises (xviii) providing a reentry sub, and positioning the reentry sub over the body; (xix) contacting a leading edge of the reentry sub with a receiving edge of the body; (xx) supplying a fluid through an interior volume of the reentry sub to register a pressure increase and confirm a seal between the reentry sub and the body.

One particular embodiment of the present invention is an isolation system for a borehole operation, comprising an isolation valve having an element positioned between a first end and a second end of the isolation valve, wherein the element is rotatable between an open position and a closed position; a first enclosed volume proximate to the first end of the isolation valve; a second enclosed volume proximate to the second end of the isolation valve, wherein the element segregates the first enclosed volume and the second enclosed volume when the element is in the closed position, and a shaft of the element extends to a side surface of the isolation valve; an actuator having an element recess configured to operatively interconnect to the shaft of the element, wherein the actuator is configured to rotate the element between the open position and the closed position; and a first alignment feature and a second alignment feature positioned on the side surface of the isolation valve, wherein the first alignment feature and the second feature combine to align the actuator and the isolation valve and to align the shaft and the element recess.

In some embodiments, a drive recess of the actuator is configured to receive the distal end of a rotatable tool, and a gearbox disposed between the drive recess and the element recess of the actuator. In various embodiments, the gearbox is configured to rotate the element recess with a greater torque than the drive recess. In certain embodiments, a first bleeding valve is positioned on the isolation valve and operatively interconnected to the first enclosed volume to control the pressure within the first enclosed volume; and a second bleeding valve is positioned on the isolation valve and operatively interconnected to the second enclosed volume to control the pressure within the second enclosed volume.

These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments, objectives, and configurations are neither complete nor exhaustive. The Background and Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the invention. Moreover, references made herein to “the invention” or aspects thereof should be understood to mean certain embodiments of the invention and should not necessarily be construed as limiting all embodiments to a particular description. The invention is set forth in various levels of detail in the Background and Summary of the Invention as well as in the attached drawings and Detailed Description and no limitation as to the scope of the invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Background and Summary of the Invention. Additional aspects of the invention will become more readily apparent from the Detailed Description particularly when taken together with the drawings.

