METHOD OF INTERVENTION IN A FAILED DEEP-SET SUBSURFACE SAFETY VALVE IN A DEEPWATER OR ULTRA-DEEPWATER SUBSEA WELL USING A LIGHT INTERVENTION VESSEL

Abstract

A method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well uses a deep-set wireline-retrievable subsurface safety valve that may be deployed via wireline into the failed deep-set tubing-retrievable subsurface safety valve. The deep-set wireline-retrievable subsurface safety valve has a closure actuation mechanism that is disposed below the closure device. In addition, the closure actuation mechanism includes a pressure-balanced piston that is exposed to wellbore fluids on both distal ends of the piston, thereby allowing the piston to actuate the closure device in deepwater and ultra-deepwater wells with significant hydrostatic head in the control line. Advantageously, the method does not require re-completion of the well and a light intervention vessel may be used as the platform for performing the intervention, rather than a conventional drilling rig or platform, substantially reducing non-productive down-time, lost profits, and costs associated with resuming production.

Claims

1. A method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well comprising: cutting or grinding a radial port in an interior facing portion of the failed deep-set tubing retrievable subsurface safety valve with an e-line wireline-deployable communication tool to communicate a hydraulic chamber housing of the failed deep-set tubing-retrievable subsurface safety valve; and running in a deep-set wireline-retrievable subsurface safety valve into a central lumen of the failed tubing-retrievable subsurface safety valve, wherein the deep-set wireline-retrievable subsurface safety valve comprises a closure actuation mechanism disposed below a closure device, and wherein the actuation mechanism comprises a pressure-balanced piston exposed to wellbore fluids on both distal ends of the piston.

2. The method of claim 1, further comprising: disposing a light intervention vessel on a well site.

3. The method of claim 1, further comprising: facilitating wireline access from a light intervention vessel to the subsea well comprising the failed tubing-retrievable subsurface safety valve.

4. The method of claim 3, wherein wireline access is provided by a riser-based system.

5. The method of claim 3, wherein wireline access is provided by a riser-less system.

6. The method of claim 3, wherein the wireline access is provided by a coiled-tubing system.

7. The method of claim 1, further comprising: locking out the failed deep-set tubing-retrievable subsurface safety valve with a wireline-deployable lockout tool.

8. The method of claim 1, further comprising: running in the wireline-deployable communication tool into an interior of the failed deep-set tubing-retrievable subsurface safety valve.

9. The method of claim 1, further comprising: landing the deep-set wireline retrievable subsurface safety valve within a no-go shoulder or other profile of the failed tubing-retrievable subsurface safety valve.

10. The method of claim 1, further comprising: locking the deep-set wireline retrievable subsurface safety valve into place at a location within the failed deep-set tubing-retrievable subsurface safety valve that facilitates communication.

11. The method of claim 1, further comprising: providing hydraulic actuation fluid from a surface-controlled pump system to the deep-set wireline-retrievable subsurface safety valve via the communicated hydraulic chamber housing of the failed tubing-retrievable subsurface safety valve.

12. The method of claim 11, wherein the surface-controlled pump system provides hydraulic actuation fluid to a wet tree that is fluidly connected to a control line that is fluidly connected to the hydraulic chamber housing of the failed tubing-retrievable subsurface safety valve.

13. The method of claim 1, wherein the closure device of the deep-set wireline retrievable subsurface safety valve comprises an equalization system configured to equalize pressure across the closure device to facilitate opening the deep-set wireline retrievable subsurface safety valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 shows the deployment of a conventional deep-set tubing-retrievable subsurface safety valve in a deepwater or ultra-deepwater subsea well.

[0009] FIG. 2 shows a conventional deep-set tubing-retrievable subsurface safety valve.

[0010] FIG. 3 shows a light intervention vessel disposed on a well site of a failed tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well in accordance with one or more embodiments of the present invention.

[0011] FIG. 4A shows communication of the failed deep-set tubing-retrievable subsurface safety valve in accordance with one or more embodiments of the present invention.

[0012] FIG. 4B shows a radial cutout formed in an interior facing surface of the failed deep-set tubing-retrievable subsurface safety valve providing access to the hydraulic chamber (not independently shown) in accordance with one or more embodiments of the present invention.

[0013] FIG. 5 shows a block diagram of a deep-set wireline retrievable subsurface safety valve for a failed deep-set tubing-retrievable subsurface safety valve in accordance with one or more embodiments of the present invention.

[0014] FIG. 6 shows a bottom facing perspective view of a portion of a deep-set wireline-retrievable subsurface safety valve in accordance with one or more embodiments of the present invention.

[0015] FIG. 7 shows an exploded view of a portion of a deep-set wireline-retrievable subsurface safety valve in accordance with one or more embodiments of the present invention.

[0016] FIG. 8A shows a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve in accordance with one or more embodiments of the present invention.

[0017] FIG. 8B shows a cross-sectional view of a portion of deep-set wireline-retrievable subsurface safety valve disposed within a failed deep-set tubing-retrievable safety valve with a ball valve in a closed state preventing flow in accordance with one or more embodiments of the present invention.

[0018] FIG. 8C shows a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve disposed within a failed deep-set tubing-retrievable subsurface safety valve with a ball valve in an opened state permitting production flow in accordance with one or more embodiments of the present invention.

[0019] FIG. 8D shows a detailed portion of a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve disposed within a failed deep-set tubing-retrievable subsurface safety valve with a ball valve in an opened state permitting flow in accordance with one or more embodiments of the present invention.

[0020] FIG. 9A shows a detailed portion of a perspective view of a ball valve of a deep-set wireline-retrievable subsurface safety valve on seat in accordance with one or more embodiments of the present invention.

[0021] FIG. 9B shows a detailed portion of a perspective view of a ball valve of a deep-set wireline-retrievable subsurface safety valve off seat under actuation pressure in accordance with one or more embodiments of the present invention.

[0022] FIG. 10A shows a cross-sectional view of a closure device, such as, for example, ball of a deep-set wireline-retrievable subsurface safety valve in a closed state in accordance with one or more embodiments of the present invention.

[0023] FIG. 10B shows a cross-sectional view of a closure device, such as, for example, ball of a deep-set wireline-retrievable subsurface safety valve in an open state in accordance with one or more embodiments of the present invention.

[0024] FIG. 11 shows a light intervention vessel performing a method of intervention in a failed deep-set tubing-retrievable subsurface safety valve in a deepwater or ultra-deepwater subsea well in accordance with one or more embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] One or more embodiments of the present invention are described in detail with reference to the accompanying figures. For consistency, like elements in the various figures are denoted by like reference numerals. In the following detailed description of the present invention, specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well-known features to one of ordinary skill in the art are not described to avoid obscuring the description of the present invention. For purposes of clarity, as used herein, top, upper, or above refer to a portion or side that is closer, whether directly or in reference to another component, to the surface above a wellbore and bottom, lower, or below refer to a portion or side that is closer, whether directly or in reference to another component, to the bottom of the wellbore.

[0026] FIG. 1 shows the deployment 100 of a conventional deep-set tubing-retrievable subsurface safety valve 105 in a deepwater or ultra-deepwater subsea well 110. In offshore operations, a bottom founded, semi-submersible, drillship, or other floating drilling rig 115 is floated onto the well site to drill a subsea well 110 to recover oil or gas reserves disposed below the seafloor 120. In deepwater applications, the water depth, W.sub.Depth, may be in a range between 3,500 and 5,000 feet. In ultra-deepwater applications, the water depth, W.sub.Depth, may be greater than 5,000 feet. The total vertical depth of the wellbore 110 may extend many thousands of feet below the seafloor 120.

[0027] During drilling and pre-production operations, a marine riser system 125 facilitates fluid communication between drilling rig 115 and subsea well 110. An SSBOP 135 is disposed above a subsea wellhead, or wet tree, 130 disposed above subsea well 110. The wellhead 130 is in fluid communication with production tubing 140 disposed within the interior of wellbore 110. In this way, a central lumen is formed that fluidly connects drilling rig 115 to the interior of wellbore 110 for the deployment of drilling equipment and other tools (not shown). During initial completion operations, deep-set tubing-retrievable subsurface safety valve 105 is deployed as an integrated part of production tubing 140, typically disposed within 200 feet of the hanger (not independently illustrated) of the wet tree 130. After completion, drilling rig 115 is moved off the well site and a Floating Production and Storage Offloading (FPSO) vessel (not shown) is typically brought in to fluidly connect to the wet tree 130 to facilitate production activities. The FPSO (not shown) typically includes a surface-based control system (not shown) that communicates hydraulic actuation fluid through the wet tree 130 to the deep-set tubing-retrievable subsurface safety valve 105 via the control line (not shown). When the operator wishes to start production, the surface-based control system (not shown) provides hydraulic pressure in the control line (not shown) that overcomes the resistance of the biasing means (not shown), causing the flapper (not shown) or valve (not shown) to open, permitting production flow towards the surface. The production fluids may be directed from the wet tree 130 to a storage tank (not shown) on the FPSO (not shown) for storage and delivery.

[0028] FIG. 2 shows a conventional deep-set tubing-retrievable subsurface safety valve 105 well-known in the art. A conventional deep-set tubing-retrievable subsurface safety valve 105 such as, for example, the valve shown and described in U.S. Pat. No. 5,310,004, may be deployed as part of the production tubing (e.g., 140 of FIG. 1) and disposed in a subsea well (e.g., 110 of FIG. 1). The valve 105 is typically set at a depth within the valve's fail-safe setting depth. The fail-safe setting depth is the maximum true vertical depth at which the valve may be set and expected to properly close under worst-case hydrostatic conditions.

[0029] As described in U.S. Pat. No. 5,310,004, valve 105 includes a central lumen 202 that extends from distal end to distal end and a flapper 204 connected to a lower portion of a housing 206 by a pivot pin 208. Valve 105 allows end-to-end communication through the central lumen 202 when flapper 204 is in the open position and prevents flow when flapper vale 204 is in the default closed position. Valve 105 includes a piston 210 and a cylinder 212 that are connected to a flow tube 214. To open valve 105, the application of hydraulic pressure, via the control line (not shown), to the top side of piston and cylinder assembly 216 causes flow tube 214 to move downward, forcing flapper 204 off of valve seat 218, opening valve 105 to production flow therethrough. In the absence of sufficient hydraulic pressure, biasing means, such as biasing spring 220 and a pressurized gas chamber 222, are biased to push flow tube 214 in an upward direction, thereby releasing flapper 204 to close valve 105. Spring 220 acts between a shoulder 224 on housing 206 and a shoulder 226 on flow tube 214. Pressurized gas chamber 222 includes a plurality of tubing coils 228 containing pressurized nitrogen.

[0030] As a failsafe, piston 210 includes a second piston 232 that is telescopically positioned in an end of first piston 210. The second piston 232 includes a first end 234 and a second end 236, where the second end 236 has a larger cross-sectional area than the first end 234. The first end 234 and second end 236 each sealably engage first piston 210 by seals 238 (not shown) and 240 (not shown). Seal 238 seals a smaller cross-sectional area than larger seal 240. The first piston 210 includes a hydraulic fluid passageway 242 that extends from a first side of the hydraulic piston and cylinder assembly 216 to the first end 234 of the second piston 232 and acts against seal 240. The second end 236 of second piston 232 is exposed to the gas pressure in chamber 222. Because the cross-sectional area of the second end 236 of second piston 232 has a larger seal area 240 than seal area 238 of first end 234, second piston 232 will remain in engagement in the end of first piston 210 with a lower gas pressure acting on second end 236 compared with hydraulic actuation fluid acting on first end 234. However, if gas pressure is lost, and unable to overcome the hydrostatic head of the hydraulic actuation fluid in the control line (not shown), the force of the gas pressure acting on second end 236 of the second piston 232 decreases allowing the hydrostatic pressure of the hydraulic fluid acting on the first end 234 to push the second piston 232 out of piston 210, thereby balancing the hydrostatic actuation fluid forces on piston 210, such that biasing spring 220 may close valve 105 safely. One of ordinary skill in the art will appreciate that the conventional deep-set tubing-retrievable subsurface safety valve described herein is merely exemplary and there are other designs, however, each of which relies on additional biasing means to assist in closing the valve against the increased hydrostatic head encountered in deep-set applications.

[0031] In the aftermath of the Deepwater Horizon incident, the use of deep-set tubing retrievable subsurface safety valves increased dramatically. While various original equipment manufacturers claim that deep-set tubing-retrievable subsurface safety valves are capable of reliable operation at substantial depth, until recently, their actual performance in deepwater and ultra-deepwater wells was not well characterized. Unfortunately, data from the field suggests that deep-set tubing retrievable subsurface safety valves have a substantially higher failure rate than that of conventional tubing-retrievable subsurface safety valves, resulting in non-commanded closures and other critical failure modes. Specifically, high-profile failures have shed light on the substantial risk these deep-set valves pose in deepwater and ultra-deepwater applications. In a litigation matter filed in the United States District Court for the Southern District of Texas, styled Hess Corporation v. Schlumberger Technology Corporation (case 4:16-CV-03415), Hess filed suit against Schlumberger for damages resulting from the alleged failure of Schlumberger's deep-set tubing retrievable subsurface safety valves deployed offshore. Hess purchased five (5) deep-set tubing-retrievable subsurface safety valves from Schlumberger for use in subsea wells in the Outer Continental Shelf of the Gulf of Mexico. As of the date of the complaint, three (3) of the five (5) deep-set tubing-retrievable subsurface safety valves deployed in deepwater subsea wells failed. According to Hess, this has resulted in significant production losses, costs associated with pulling and replacing the failed valves, costs associated with restoring production capabilities, property loss and damage, and deferred production costs associated with schedule delays on subsequent producer and injector wells. The subsea wells at issue were drilled in approximately 4,300 feet of water, with the wells themselves having an approximate total vertical depth of approximately 25,000 feet. These wells produced between 2,000 and 16,500 barrels of oil per day, before being shut-in by non-commanded valve closure and potentially other failure modes. In quantifying the substantial costs incurred due to these failures, Hess complained that, with respect to a single subsea well, it took 64 days and cost approximately $60 million dollars to restore production operations, exclusive of lost profits.

[0032] The issues complained of in the above-noted litigation highlight a longstanding problem in the industry that threatens the financial viability and overall feasibility of deepwater and ultra-deepwater plays. While tubing-retrievable subsurface safety valves are required in deepwater and ultra-deepwater applications, unfortunately, when they fail, the well must be re-completed in a time-consuming and expensive process that requires floating a drilling rig back onto the well site, pulling the production tubing, replacing the failed tubing-retrievable subsurface safety valve, and re-deploying the production tubing with the replaced tubing-retrievable subsurface safety valve. In addition to the substantial costs associated with the above-noted re-completion activities, profits lost for the duration of these operations are substantial. As noted in the real-world example, the frequency of failure of deep-set tubing-retrievable subsurface safety valves and the substantial time and cost required to re-complete a well jeopardize the safety of operations and many operators are shying away from such deepwater and ultra-deepwater plays, where a significant amount of oil and gas reserves are known to exist.

[0033] In a failed conventional, not deep-set, tubing-retrievable subsurface safety valve set at a shallower depth, typically less than 3,500 feet, one avenue for proceeding is to deploy a conventional wireline-retrievable subsurface safety valve within the failed tubing-retrievable subsurface safety valve. The wireline-retrievable subsurface safety valve may be run into the well on a lock that locates the wireline-retrievable subsurface safety valve within a desired location of the failed tubing-retrievable subsurface safety valve. The wireline-retrievable subsurface safety valve typically includes packing elements that isolate the hydraulic chamber that was previously used to control the now failed tubing-retrievable subsurface safety valve. The process of opening up the original hydraulic actuation pathway of the failed tubing-retrievable subsurface safety valve for use with the wireline-retrievable subsurface safety valve is referred to as communication. Once communication has been achieved, a surface-controlled pump system may pump hydraulic actuation fluid through the hydraulic chamber of the failed tubing-retrievable subsurface safety valve to the hydraulic chamber of the wireline-retrievable subsurface safety valve to hydraulically actuate the wireline-retrievable subsurface safety valve in a similar manner to that of the failed tubing-retrievable subsurface safety valve.

[0034] While the wireline-retrievable subsurface safety valve potentially reduces the flow rate of production fluids, it allows such wells to continue to produce after failure of the tubing-retrievable subsurface safety valve without the attendant costs of recompleting the well. Similar to the tubing-retrievable subsurface safety valve, the conventional wireline-retrievable subsurface safety valve is a failsafe device that fails in the closed state such that production flow is halted whenever hydraulic actuation pressure is sufficiently reduced or removed. As such, the conventional wireline-retrievable subsurface safety valve requires the positive application of hydraulic actuation pressure to open a flapper or valve to permit production flow through the subsurface safety valve. In the event of a failure or catastrophic event, once the hydraulic actuation is lost, the energy stored in a power spring disposed above the flapper of the wireline-retrievable subsurface safety valve causes the subsurface safety valve to close, thereby safely halting production flow.

[0035] Notwithstanding, conventional wireline-retrievable subsurface safety valves cannot be used in deepwater and ultra-deepwater subsea wells. The depth at which conventional wireline-retrievable subsurface safety valves may be deployed is constrained by the ability to provide sufficient hydraulic activation pressure at the setting depth. Conventional wireline-retrievable subsurface safety valves require the application of hydraulic actuation pressure to compress a bias spring disposed above the flapper or valve to controllably open the valve when production flow towards the surface is desired. If the conventional wireline-retrievable subsurface safety valve is deployed at a depth that exceeds the ability of the hydraulic actuation to overcome the hydrostatic head in the control line, the conventional wireline-retrievable subsurface safety valve cannot be opened, thereby preventing production flow.

[0036] Further, conventional wireline-retrievable subsurface safety valves require a bias spring disposed above the flapper or valve that is capable of storing sufficient energy to offset the increased hydrostatic head in the control line, at the setting depth, such that it can reliably fail in the closed state. However, this is not feasible because the size of the bias spring disposed above the flapper or valve is physically constrained by the inner diameter of the wireline-retrievable subsurface safety valve itself. Since the conventional wireline-retrievable subsurface safety valves require an inner diameter capable of fluidly communicating production flow, the amount of space above the flapper or valve is physically constrained, thereby limiting the amount of energy capable of being stored in the bias spring and, as a consequence, substantially limiting the depth at which the conventional wireline-retrievable subsurface safety valve may be set, typically much shallower than 3,500 feet.

[0037] As such, the current state of the art in the industry is to deploy a SSBOP and deep-set tubing-retrievable subsurface safety valve as a permanently installed two barrier system for deepwater and ultra-deepwater subsea wells. When the tubing-retrievable subsurface safety valve fails, for whatever reason, the operator must undertake a complex, time-consuming, and expensive process to re-complete the well in an attempt to resume production operations. As noted above, a drilling rig must be brought onto the well site, the production tubing must be pulled, the failed deep-set tubing-retrievable subsurface safety valve must be replaced, the production tubing must be run back into the well, and the well must be completed with a wellhead or wet tree.

[0038] Accordingly, in one or more embodiments of the present invention, a method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well does not require re-completion of the well and substantially reduces non-productive down-time, lost profits, and costs associated with resuming production. Advantageously, the production tubing, including the failed deep-set tubing-retrievable subsurface safety valve do not have to be pulled, dramatically simplifying operations and reducing costs. A light intervention vessel may be used as the platform for performing the intervention, rather than a conventional drilling rig or platform, substantially expediting operations and reducing costs typically associated with floating a large drilling rig back onto the well site. A deep-set wireline-retrievable subsurface safety valve may be deployed via wireline into the failed deep-set tubing-retrievable subsurface safety valve, where the deep-set wireline-retrievable subsurface safety valve has a closure actuation mechanism that is disposed below the closure device. In addition, the closure actuation mechanism includes a pressure-balanced piston that is exposed to wellbore fluids on both distal ends of the piston, thereby allowing the piston to actuate the closure device in deepwater and ultra-deepwater wells with significant hydrostatic head in the control line.

[0039] FIG. 3 shows a light intervention vessel 305 disposed on a well site 310 of a failed tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) disposed in a deepwater or ultra-deepwater subsea well (e.g., 110 of FIG. 1) in accordance with one or more embodiments of the present invention. While the use of light intervention vessels for different reasons is well-known in the art, such vessels 305 may be used with one or more methods of the claimed invention to facilitate deepwater or ultra-deepwater intervention in failed tubing-retrievable subsurface safety valves. Light intervention vessels 305 are small, dynamically positioned, and monohulled vessels that are capable of being disposed on the wellsite 310 much faster than large semi-submersible, drillship, or other large drilling rigs or platforms (e.g., 115 of FIG. 1). Once disposed on the wellsite 310, light intervention vessel 305 facilitates wireline access to the subsea well (e.g., 110 of FIG. 1) where the failed tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) is disposed. In certain embodiments, wireline access may be provided by a riser-based system (not shown). In other embodiments, wireline access may be provided by a coiled-tubing-based 315 system. In still other embodiments, wireline access may be provided by a slickline-based 315 system. In still other embodiments, wireline access may be provided by wireline-based 315 system. One of ordinary skill in the art will recognize that any system that provides wireline access such that communication tools may be deployable, and a deep-set wireline retrievable subsurface safety valve (not shown) may be landed, within the failed deep-set tubing retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) may be used in accordance with one or more embodiments of the present invention.

[0040] In certain embodiments, a robotically operated vehicle (ROV) 320 may be tethered to an ROV umbilical 325 to observe and assist in the intervention operations taking place at or near the seafloor 120. After wellbore access is achieved, a wireline-deployable lockout tool (not shown) is run into the wellbore (e.g., 110 of FIG. 1) to lock out the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2). In certain embodiments, a deformation type of lockout tool (not shown) may be used. Deformation-type lockout tools locate a positive shoulder of a known-location, such as, for example, a no-go shoulder or profile, often located in the top sub of the tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2). Downward jarring on the tool engages the flowtube (e.g., 214 of FIG. 2) of the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2), causing the flowtube (e.g., 214 of FIG. 2) to shift downward causing the flapper (e.g., 204 of FIG. 2) or valve (not shown) to open. Simultaneously, prongs or specially adapted hammers (not shown) protrude from the deformation-type lockout tool (not shown) and deform the flowtube (e.g., 214 of FIG. 2) permanently opening the flapper (e.g., 204 of FIG. 2). In some applications, the flowtube (e.g., 214 of FIG. 2) may be stuck such that it cannot be moved. In such circumstances, a cylindrical metal coil (not shown) may be deployed with the lockout tool and deposited in or near the flapper (e.g., 204 of FIG. 2) housing to permanently open the flapper (e.g., 204 of FIG. 2). Once locked out, the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) is locked into the open state, such that fluids are freely communicated through the tubing-retrievable subsurface safety valve.

[0041] FIG. 4A shows communication of the failed deep-set tubing-retrievable subsurface safety valve 105 in accordance with one or more embodiments of the present invention. It is well-known in the art that you must communicate a failed subsurface safety valve in order to operate the insertable valve. However, a deep-set wireline-retrievable subsurface safety valve deployed in deepwater and ultra-deepwater subsea wells present special challenges because communication of failed deep-set tubing-retrievable subsurface safety valves (e.g., 105) has never been attempted or accomplished to date. The objective here is the same as that used in non-deepwater subsea wells, namely, to locate within the failed deep-set tubing retrievable subsurface safety valve 105 a location (e.g., 410) where a communication pathway may be opened with the hydraulic chamber (not shown) of the failed tubing-retrievable subsurface safety valve 105 such that hydraulic actuation fluids (not shown) may flow from the hydraulic chamber (not shown) of the failed tubing-retrievable subsurface safety valve 105 into to the hydraulic pathway of the deep-set wireline retrievable subsurface safety valve (not shown). A wireline-deployable communication tool 405 may be run into an interior diameter of the failed deep-set tubing-retrievable subsurface safety valve 105 and powered by an electric or e-line (not shown). As shown in the figure, the communication tool 405 may be lowered into the failed deep-set tubing-retrievable subsurface safety 105 and precisely located by locating off of a lock profile or no-go shoulder or a distance from a closed flapper (not shown).

[0042] Once properly located, the communication tool 405 may be turned on to remove material and form a radial cutout 410 that intersects at least one piston hole in the hydraulic chamber (not shown) of the failed deep-set tubing-retrievable subsurface safety valve 105, thereby establishing communication to enable operation of an insert valve, such as a deep-set wireline-retrievable subsurface safety valve (not shown). Continuing, FIG. 4B shows a radial cutout 410 formed in an interior facing surface of the failed deep-set tubing-retrievable subsurface safety valve 105 providing access to the hydraulic chamber (not independently shown) in accordance with one or more embodiments of the present invention. In certain embodiments, the method of intervention further includes cutting or grinding a radial port in an interior facing portion of the failed deep-set tubing-retrievable subsurface safety valve with a wireline-deployable communication tool to communicate a hydraulic chamber (not independently illustrated) of the failed deep-set tubing-retrievable subsurface safety valve. Prior to running in the deep-set wireline-retrievable subsurface safety valve, other tools may be used to clear obstructions, polish the surfaces, or take other actions to facilitate landing the deep-set wireline-retrievable subsurface safety valve in a manner that minimizes damage and increases the likelihood of success.

[0043] FIG. 5 shows a block diagram of a deep-set wireline retrievable subsurface safety valve 500 for a failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) in accordance with one or more embodiments of the present invention. A deep-set wireline retrievable subsurface safety valve 500 must be capable of being deployed in failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2) in a deepwater or ultra-deepwater subsea well and provide failsafe protection like any other subsurface safety valve. Specifically, the deep-set wireline retrievable subsurface safety valve must be capable of opening the flapper, valve, or closure device 510 upon application of hydraulic actuation pressure from the surface and fully closing when the hydraulic actuation pressure is sufficiently reduced or removed or other contingency arises. In order to achieve this functionality in deepwater and ultra-deepwater subsea wells, where existing wireline-retrievable subsurface safety valves are not capable of operating, the closure actuation mechanism 520 is disposed below the closure device 510 and the closure device 510 includes a pressure equalization feature.

[0044] Once communication is complete, a deep-set wireline-retrievable subsurface safety valve 500 is run into a central lumen of the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105 of FIG. 1 and FIG. 2). The closure actuation mechanism 520 of the deep-set wireline retrievable subsurface safety valve 500 may be disposed below the closure device 510. In certain embodiments, the closure actuation mechanism 520 comprises a pressure-balanced piston (not shown) that is exposed to wellbore fluids on both sides, or exposed distal ends, of the piston. Because closure actuation mechanism 520 is pressure-balanced and the energy to close the valve 500 is stored below the closure device 510, the closing ability of valve 500 is tubing pressure insensitive, and capable of reliable operation at depth. In addition, closure device 510 comprises an equalization feature that equalizes pressure across the closure device to facilitate opening the valve 500 regardless of the hydrostatic head at the setting depth in deepwater or ultra-deepwater.

[0045] For purposes of illustration, an embodiment of a deep-set wireline-retrievable subsurface safety valve 500 is described herein. However, one of ordinary skill in the art, having the benefit of this disclosure, will appreciate that other designs that meet the above-noted requirements may be used in accordance with one or more embodiments of the present invention and their usage is contemplated by one or more methods of the claimed invention. FIG. 6 shows a bottom facing perspective view of a portion of a deep-set wireline-retrievable subsurface safety valve 500 in accordance with one or more embodiments of the present invention. In one or more embodiments of the present invention, a deep-set wireline-retrievable subsurface safety valve 500 may include a locking mechanism (not shown) to secure deep-set wireline-retrievable subsurface safety valve 500 within an inner diameter of a failed deep-set tubing retrievable subsurface safety valve (e.g., 105), an upper packing housing (not shown), an upper packing element (not shown) that may create an upper hydraulic seal on an annulus between the deep-set wireline-retrievable subsurface safety valve 500 above a hydraulic fluid intake port 608, and a spacer 604. One of ordinary skill in the art will recognize that the upper packing housing (not shown) and the upper packing element (not shown) may be substantially similar to that of lower packing housing 624 and lower packing element 620 described in more detail herein. Spacer 604 may include the hydraulic fluid intake port 608 that connects an exterior of spacer 604 to a central lumen, or passageway, disposed therein and have a length to dispose the hydraulic fluid intake port 608 below a flapper or valve (not shown) of the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105) in which the deep-set wireline-retrievable subsurface safety valve 500 is disposed. The hydraulic fluid intake port 608 receives surface-injected hydraulic actuation fluid (not shown) from the annulus surrounding the safety valve 500 when deployed within the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105). Deep-set wireline-retrievable subsurface safety valve 500 may also include lower packing element 620 to create a lower hydraulic seal on the annulus between deep-set wireline-retrievable subsurface safety valve 500 and the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105) below hydraulic fluid intake port 608 and the flapper or valve (not shown) of the failed deep-set tubing-retrievable subsurface safety valve (e.g., 105), a lower packing housing 624, a seat housing 644, a plurality of flow ports 648 disposed about the seat housing 644, a hydraulic chamber housing 630, a spring housing 690, and a nose cap 698.

[0046] FIG. 7 shows an exploded view of a portion of a deep-set wireline-retrievable subsurface safety valve 500 in accordance with one or more embodiments of the present invention. In one or more embodiments of the present invention, deep-set wireline-retrievable subsurface safety valve 500 may include a spacer 604 having a hydraulic fluid intake port 608 and a plurality of O-rings 612 and 616 that seal the connection between a lower packing housing 624 and spacer 604. A lower packing element 620 covers a portion of lower packing housing 624 and a plurality of double O-rings 628 and 632 seal the connection interface between the lower packing housing 624 and seat housing 644. A hard seat 636 and a soft seat 640 partially receive a ball 652, which is one type of closure device (e.g., 510 of FIG. 5) contemplated herein. Seat housing 644 may include a plurality of flow ports 648. One or more setting screws 654 may be disposed within ball 652. Deep-set wireline-retrievable subsurface safety valve 500 may also include an upper retention screw 656, an upper power seal 660, a plurality of double O-rings 664 and 668 that seal the connection interface between hydraulic chamber housing 672 and seat housing 644, a double O-ring 676 that seals the connection interface between hydraulic chamber housing 672 and spring housing 690, a power piston 680, an intermediate power seal 684, an intermediate retention screw 686, a spring ring 687, a power spring 689, a lower retention screw 692, a lower power seal 694, a double O-ring 696 that seals the connection interface between spring housing 690 and nose cap housing 698, and a nose cap plug 699, discussed in more detail herein.

[0047] FIG. 8A shows a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve 500 in accordance with one or more embodiments of the present invention. Spacer 604 may include a central lumen through which wellbore fluids (not shown) may flow when ball 652 valve is moved off soft seat 640. A lower packing housing 625 may connect to spacer 604 and may include a first hydraulic fluid passage 610 to align with hydraulic fluid intake port 608 of spacer 604. When hydraulic actuation fluid (not shown) is injected from the surface (not shown), hydraulic actuation fluid (not shown) may flow into the hydraulic fluid intake port 608, through first hydraulic fluid passage 610 that traverses the hydraulic seal formed by the upper packing element (not shown) and lower packing element 620 into a second hydraulic fluid passage 611 and a third hydraulic fluid passage 613. If sufficient hydraulic actuation pressure is provided, the hydraulic fluid exerts a downward force on a piston shoulder chamber 681 that causes power piston 680 to move down and compress power spring 689, thereby moving ball 652 off soft seat 640 (not shown).

[0048] Continuing, FIG. 8B shows a cross-sectional view of a portion of deep-set wireline-retrievable subsurface safety valve 500 disposed within a failed deep-set tubing-retrievable safety valve 105 with a ball 652 valve in a closed state preventing flow in accordance with one or more embodiments of the present invention. In one or more embodiments of the present invention, deep-set wireline-retrievable subsurface safety valve 500 may be landed within a no-go shoulder profile of failed deep-set tubing-retrievable safety valve 105 (which is locked open and communicated prior to landing). A locking mechanism (not shown) may be used to secure deep-set wireline-retrievable subsurface safety valve 500 to failed deep-set tubing-retrievable subsurface safety valve 105. An upper packing (not shown) and lower packing 620 may create a hydraulic seal in an annulus surrounding a portion of the deep-set wireline-retrievable subsurface safety valve 500. A hydraulic fluid intake port 608 may receive hydraulic fluid in the annulus surrounding the deep-set wireline-retrievable subsurface safety valve 500 within the hydraulic seal from an FPSO disposed on a surface (not shown) of a body of water (not shown). The hydraulic actuation fluid (not shown) may be communicated via first hydraulic fluid passage 610, second hydraulic fluid passage 611, and third hydraulic fluid passage 613 disposed below the hydraulic seal to a piston shoulder chamber 681 and, if sufficient hydraulic actuation pressure is provided, may exert a downward force on piston shoulder chamber 681 that causes power piston 680 to move down and compress a power spring 689 disposed within an a gas chamber. A ball 652 valve may be disposed above the hydraulic chamber and may be connected to power piston 680. Absent sufficient hydraulic actuation pressure, power spring 689 uncompresses and ball 652 is moved fully on soft seat 640 and hard seat 636, thereby preventing formation fluids (not shown) from flowing toward the surface (not shown) through deep-set wireline-retrievable subsurface safety valve 500.

[0049] Power spring 689 may be disposed within a gas chamber formed by spring housing 690, intermediate power seal 684, hydraulic chamber housing 672, lower power seal 684, and nose cap housing 698. The gas chamber may be voided, filled with air, or charged with one or more gases, including potentially, nitrogen, although nitrogen charging is not required to uncompress power spring 689 at deepwater or ultra-deepwater depths. While upper power seal 660 and lower power seal 694 are in communication with production tubing pressure, both seals have the same diameter and are disposed on opposing ends of power piston 680. As such, their pressure areas are the same and the forces acting on the power piston 680 effectively cancel each other out, thus power piston 680 is said to be pressure balanced. As such, power spring 689 may not be sensitive to production tubing pressure. Thus, the hydraulic actuation pressure required to compress power spring 689 may be substantially less than the production tubing pressure and when that actuation pressure is sufficiently reduced or removed, power spring 689 does not require nitrogen charging to uncompress and fully close deep-set wireline-retrievable subsurface safety valve 500 at a deepwater or ultra-deepwater depths.

[0050] Continuing, FIG. 8C shows a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve 500 disposed within a failed deep-set tubing-retrievable subsurface safety valve 105 with a ball 652 valve in an opened state permitting production flow in accordance with one or more embodiments of the present invention. As previously discussed, failed deep-set tubing-retrievable subsurface safety valve 105 has been communicated (not shown) and flapper 204 is locked open. Deep-set wireline-retrievable subsurface safety valve 500 has been landed within a no-go shoulder or internal landing profile (not shown) of failed deep-set tubing-retrievable subsurface safety valve 105 and locked (not shown) or otherwise secured to failed deep-set tubing-retrievable subsurface safety valve 105. An upper packing (not shown) element forms an upper hydraulic seal in the annulus between deep-set wireline-retrievable subsurface safety valve 500 and failed deep-set tubing-retrievable subsurface safety valve 105. Lower packing element 620 forms a lower hydraulic seal in the annulus between deep-set wireline-retrievable subsurface safety valve 500 and failed deep-set tubing-retrievable subsurface safety valve 105. The upper and lower hydraulic seals form a hydraulic seal. Hydraulic fluid (not shown) may be injected from the surface (not shown) via the puncture (not shown) into the annulus surrounding the deep-set wireline-retrievable subsurface safety valve 500 disposed between the upper and lower hydraulic seals. The injected hydraulic fluid (not shown) in the annulus enters the hydraulic fluid intake port 608 and flows through first hydraulic fluid passage 610, second hydraulic fluid passage 611, and third hydraulic fluid passage 613 to a piston shoulder chamber 681.

[0051] Continuing, FIG. 8D shows a detailed portion of a cross-sectional view of a portion of a deep-set wireline-retrievable subsurface safety valve 500 disposed within a failed deep-set tubing-retrievable subsurface safety valve 105 with a ball 652 valve in an opened state permitting flow in accordance with one or more embodiments of the present invention. As shown in the detailed view, power piston 680 may be connected on a first distal end to ball 652 by one or more set screws 653 and on a second distal end to a nose cap housing (e.g., 698 of FIG. 8C). Power piston 680 may extend through hydraulic chamber housing 672. Spring ring 687 may be disposed on a top distal end of power spring 689. Upper power seal 660 may seal an annulus surrounding power piston 680 and an upper portion of hydraulic chamber housing 672. Upper power seal retainer 656 may retain upper power seal 660 in place. Intermediate power seal 684 may seal an annulus surrounding power piston 680 and a lower portion of hydraulic chamber housing 672. Intermediate power seal retainer 686 may retain intermediate power seal 684 in place. As such, any pressure trapped between upper power seal 660 and intermediate power seal 684 forces power piston 680 down. If the hydraulic actuation fluid (not shown) is provided at the actuation pressure or higher, hydraulic fluid enters third hydraulic fluid passage 613 and piston shoulder chamber 681, forcing power piston 680 down, compressing power spring 689, and moving ball 652 off soft seat 640 and hard seat 636. When ball 652 is off soft seat 640, formation fluids in the annulus between spring housing 690 and production tubing 691 enter deep-set wireline-retrievable subsurface safety valve 500. A plurality of flow ports 648 may allow fluid communication from the annulus surrounding the deep-set wireline-retrievable subsurface safety valve 500 below the hydraulic seal into a central lumen of the deep-set wireline-retrievable subsurface safety valve 500 that is exposed when ball 652 is moved off soft seat 640.

[0052] FIG. 9A shows a detailed portion of a perspective view of a ball 652 valve of a deep-set wireline-retrievable subsurface safety valve 500 on seat 640 in accordance with one or more embodiments of the present invention. Absent sufficient hydraulic actuation pressure, first hydraulic fluid passage (not shown), second hydraulic fluid passage 611, third hydraulic fluid passage 613, and piston shoulder chamber 681 may be voided. Continuing, FIG. 9B shows a detailed portion of a perspective view of a ball 652 valve of a deep-set wireline-retrievable subsurface safety valve 500 off seat 640 under actuation pressure in accordance with one or more embodiments of the present invention. When sufficient actuation pressure is applied, hydraulic fluid may be injected from the surface (not shown) into a hydraulic fluid intake port (not shown) and communicated via a first hydraulic fluid passage (not shown) disposed within the lower packing housing (not shown) to second hydraulic fluid passage 611 disposed within seat housing 644. Second hydraulic fluid passage 611 may communicate hydraulic fluid to third hydraulic fluid passage 613 of hydraulic chamber housing 672. Third hydraulic fluid passage 613 may communicate hydraulic fluid to piston shoulder chamber 681.

[0053] FIG. 10A shows a cross-sectional view of a closure device, such as, for example, ball 652 of a deep-set wireline-retrievable subsurface safety valve 500 in a closed state in accordance with one or more embodiments of the present invention. When deep-set wireline-retrievable subsurface safety valve 500 is in the closed state, ball 652 is on seat 636, thereby preventing production flow through flow ports 648. When the operator wishes to open valve 500, hydraulic actuation pressure is communicated via the control line (not shown). As it begins to pressure up, production fluids 1005 may flow through flow ports 648 and into equalization ports 1010 to dart ports 1020 and then to the other side of closure device 652 via insert 1040 and insert equalization ports 1030. Over time, this has the effect of equalizing the pressure from below the closure device 652 with the pressure above closure device 652, thereby equalizing the pressure across it. Continuing, FIG. 10B shows a cross-sectional view of a closure device, such as, for example, ball 652 of a deep-set wireline-retrievable subsurface safety valve 500 in an open state in accordance with one or more embodiments of the present invention. As the hydraulic actuation pressure increases, and the pressure across the closure device 652 is equalized, closure device 652 moves off seat hard 636 and soft seat 640, thereby enabling production flow through flow ports 648.

[0054] FIG. 11 shows a light intervention vessel 305 performing a method of intervention in a failed deep-set tubing-retrievable subsurface safety valve 105 in a deepwater or ultra-deepwater subsea well 110 in accordance with one or more embodiments of the present invention. When a deep-set tubing-retrievable subsurface safety valve 105 disposed in a deepwater or ultra-deepwater well fails, for whatever reason, a light intervention vessel 305 may be brought onto the well site. The light intervention vessel 305 may establish access to the interior of the production tubing 140 disposed within subsea well 110 via a coiled-tubing, slickline, or wireline system. A wireline-deployable lockout tool or tools may be run in to an interior of the failed tubing-retrievable subsurface safety valve 105 to facilitate locking out the failed valve 105 in the open position. A wireline-deployable communication tool (not shown) may be run into the interior of the failed deep-set tubing-retrievable subsurface safety valve 105. The communication tool may be precisely located to facilitate communicating the failed valve 105. In certain embodiments, the communication tool may cut or grind a radial port into an interior facing portion of the failed deep-set tubing retrievable subsurface safety valve 105 to communicate a hydraulic chamber housing of the failed deep-set tubing-retrievable subsurface safety valve and potentially prepare the failed valve 105 to receive the deep-set wireline retrievable subsurface safety valve 500 (not shown).

[0055] Once locked out and communicated, a deep-set wireline retrievable subsurface safety valve 500 (not shown) may be run into a central lumen of the failed tubing-retrievable subsurface safety valve 105. The deep-set wireline-retrievable subsurface safety valve 500 (not shown) may be landed within a no-go shoulder or other profile of the failed tubing-retrievable subsurface safety valve 105. Once landed, the deep-set wireline-retrievable subsurface safety valve 500 (not shown) may be locked into place at a location within the failed tubing-retrievable subsurface safety valve 105 that facilitates communication with the hydraulic chamber of the failed tubing-retrievable subsurface safety valve 105. Once installed, an FPSO 1100 may provide hydraulic actuation fluid from a surface-controlled pump system to the deep-set wireline-retrievable subsurface safety valve via a conduit that fluidly connects the wet tree 130 to the control line (not shown) of the failed deep-set tubing-retrievable subsurface safety valve 105. Because deep-set wireline-retrievable subsurface safety valve 500 (not shown) includes a closure actuation mechanism that is disposed below the closure device, where the actuation mechanism includes a pressure-balanced piston that is exposed to wellbore fluids on both distal ends of the piston, and the closure device includes an equalization system that equalizes pressure across the closure device to facilitate opening, the deep-set wireline-retrievable subsurface safety valve is capable of operation at deepwater and ultra-deepwater depths.

[0056] Advantages of one or more embodiments of the present invention may include one or more of the following:

[0057] In one or more embodiments of the present invention, method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well does not require re-completion of the well and substantially reduces non-productive downtime, lost profits, and costs associated with resuming production. Advantageously, the production tubing, including the failed deep-set tubing-retrievable subsurface safety valve, does not have to be pulled, dramatically simplifying operations and reducing costs.

[0058] In one or more embodiments of the present invention, method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well may use a light intervention vessel rather than a conventional drilling rig, substantially expediting operations and reducing costs.

[0059] In one or more embodiments of the present invention, method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well uses a deep-set wireline-retrievable subsurface safety valve having a closure actuation mechanism disposed below a closure device.

[0060] In one or more embodiments of the present invention, method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well uses a deep-set wireline-retrievable subsurface safety valve having an actuation mechanism including a pressure-balanced piston that is exposed to wellbore fluids on both distal ends of the piston, thereby allowing the piston to actuate the closure device in deepwater and ultra-deepwater subsea wells with significant hydrostatic head.

[0061] In one or more embodiments of the present invention, method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well uses a deep-set wireline-retrievable subsurface safety valve having a closure device that includes equalization means configured to equalize pressure across the closure device to facilitate opening the closure device.

[0062] In one or more embodiments of the present invention method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well establishes surface-control by communicating the hydraulic chamber housing of the failed deep-set tubing retrievable subsurface safety valve with the hydraulic chamber of the wireline-retrievable subsurface safety valve.

[0063] While the present invention has been described with respect to the above-noted embodiments, those skilled in the art, having the benefit of this disclosure, will recognize that other embodiments may be devised that are within the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the appended claims.