Patent Grant
6889771
1. Field of the Invention
The present invention relates generally to check valve systems that are typically required by industry standards for coiled tubing well interventions. More specifically, the present invention concerns a check valve system having the capability of being controlled by selective mechanical cycling movement or flow responsive movement of tool components to permit controlled selection of a direct circulating flow mode or a reverse circulating flow mode, thus permitting the check valve tool to assist in the performance of servicing operations such as sand cleanout or well flow up a section of, or the entire, coiled tubing string.
2. Description of Related Art
It is a safety standard in coiled tubing operations to have a check valve with a minimum of two pressure barriers in the tool string. In many coiled tubing operations, such as fracturing and well cleanout operations, it is desirable to reverse circulate through the coiled tubing. Reverse circulating (flowing upwardly within the passage of the coiled tubing, instead of downwardly) is not possible when conventional dual check valves are employed.
It is a principal feature of the present invention to provide a novel check valve mechanism or tool for use in well applications, particularly when the tubing being utilized within the well is coiled tubing, to accommodate industry safety standards and to selectively control the check valve mechanism for both direct circulation flow and reverse circulation flow.
It is another feature of the present invention to provide a novel dual check valve mechanism or tool which, with pipe manipulation, i.e., up and down movement, can accomplish selective indexing of a J-slot indexing mechanism for converting the valve mechanism to a direct circulation mode and reverse circulation mode.
It is also within the scope of the present invention to provide a novel dual check valve mechanism or tool which may take the form of any of several different operational embodiments, including drag spring induced operation, motion induced operation, cycle induced operation, flow induced operation, and compression induced operation.
It is another feature of the present invention to provide a novel dual check valve mechanism or tool which can be simply and efficiently re-configured from direct circulation flow to reverse circulation flow as desired for specific well service activities that are ordinarily not possible with conventional dual check valve mechanisms, and can be quickly restored to a safe condition for direct circulating flow only by using a drop ball/pressure induced override procedure or tension to actuate the dual check valves for closing responsive to reverse circulating flow.
Briefly, the various objects and features of the present invention are realized by providing a controllable reversing valve mechanism which has a mode for direct circulating flow and is actuated for reverse flow by cyclic up and down motion of tubular well tool components to achieve relative positioning of the tool components. Selective actuation, indexing, or positioning of the tubular components of the dual check valve mechanism between a direct circulating flow mode and a reverse circulating flow mode is achieved by simple relative linear movement of tool components or by a J-slot positioning indexing mechanism to selectively accomplish normal downward check valve controlled fluid flow and to achieve a flow condition permitting upward or reverse flow of fluid from the annulus of the well through the tool bore. The preferred embodiment of the present invention is a drag spring reversing valve which provides the number and arrangement of check valves that are required by industry standards and, with pipe manipulation, actuates the valve mechanism for reverse circulation as well as direct circulation, then with further pipe or tubular component manipulation, reverts the check valve mechanism to its direct circulation mode, allowing only direct circulation.
When the reverse circulating flow path is open, direct and reverse flow are possible. When the direct circulating flow path (flow down the inside of the coiled tubing) is open, only direct circulation is possible. Due to the risk of bringing unknown production fluids up the coiled tubing to the surface, reverse flow is typically not allowed unless an exemption is granted. An application for the present invention is in wells where a reverse flow sand cleanout is performed down to sand within the well casing that is typically 100 feet (30.5 meters) above the casing perforations.
Reverse circulating flow well cleanout procedures with the reversible dual check valve tool of the present invention use the high velocity fluid inside the coiled tubing to transport sand, whereas with direct flow the velocity of the fluid between the coiled tubing and the casing is much lower and often an expensive foam cleanout is required to entrain the sand under lower velocity flow conditions and transport the sand to the surface. Thus, reverse circulation flow is preferable for sand removal from wells. During reverse circulating flow the annulus of the well is pressurized from the surface. With the ability to close the check valve and with the well kept overbalanced by tubing or casing pressure that exceeds formation pressure, reverse circulation can be performed closer to the perforations of the well casing than is presently allowed under industry safety standards.
The drag spring actuated dual check valve tool, which is the preferred embodiment of the present invention can be configured for two operating modes:
The J-slot pin itself does not act as a stop in any of the three positions of the tool; rather, it establishes a guiding relation for relative linear movement of the tubular housing and inner tubular member and it causes rotational indexing of the J-slot sleeve responsive to linear upwardly and downwardly cycling movement of the tool components. Compression load is taken by the facing shoulders 64 and 66 between the connector fitting 70 and the primary seal carrier fitting 46. Tension load is taken by J-pin mount shoulder 95, shown in
According to the preferred embodiment, an up and down cycle of the coiled tubing is necessary to move the J-slot sleeve between reverse circulating and direct circulating flow paths. In the cycle operated mode, while running the tool into a well, the reverse circulating flow path is typically closed. Often, while running the tool into the hole, a pull test is done to check mechanical friction between the coiled tubing and the wellbore, thus the tool must be cycled twice to return to the direct flow position. At the desired depth the tool string is picked up, then lowered again, which opens the reverse circulating flow path. Another up and down cycle of the coiled tubing closes the reverse circulating flow path. The alternating operation is accomplished via the J-slot position indexing geometry of the J-slot sleeve of the tool. The operator may choose to run the tool into the hole with either the direct or reverse circulating flow path initially open. When the reverse circulating flow path is open, direct and reverse flow is possible. When the reverse circulating flow path is closed, only direct circulation is possible.
According to the preferred embodiment of the present invention one or more drag springs are employed to provide the driving force for both the motion operated and cycle operated modes. The drag spring must have adequate force to operate the mechanism in the well casing, typically 4.1 to 6.4 inches (104 to 163 mm) inner diameter. The drag spring is designed to have a low spring rate in order to limit the drag force passing through the pipe nipple, typically 3.725 inches (95 mm) inner diameter. The drag spring is also designed to be in tension either running the tool into the hole or pulling the tool out of the hole. This is accomplished by stops on the drag spring support mandrel. The stops are chamfered and knurled in order to ensure the housing does not rotate while the J-slot sleeve is being rotatably indexed during linear cycling of the tubular housing and the inner tubular member.
To separate a portion of the inner tubular member and remove it from its valve open position within the valve housing of the tool, the disconnect type check valve mechanism can be coupled to a pressure responsive drop ball type force responsive disconnect or a tensile, i.e., pulling force responsive, type of disconnect. The dual check valve tool can also be coupled to a pressure operated disconnect, causing disconnection to occur responsive to pressure injection through the coiled tubing. This disconnect type check valve mechanism can also be used for coiled tubing fracturing operations currently operating under a safety exemption allowing operation without check valves. The disconnect type check valve mechanism can quickly and simply restore the valve mechanism to its direct circulating mode and thereby enhances the safety of the tool during acid fracturing operations. Also, the disconnect mechanism of the tool can function at any position of the tubular housing and inner tubular member.
So that the manner in which the above recited features, advantages, and objects of the present invention are attained can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof illustrated in the appended drawings, which drawings are incorporated as a part hereof.
It is to be noted however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the Drawings:
Referring now to the drawings and first to
For injection of fluid through the coiled tubing and dual check valve mechanism and into the well, a conduit 30 is connected to the centermost coil of the coiled tubing on the storage reel 12 and permits fluid from a supply tank 32 to be pumped through the coiled tubing by a pump 34. For reverse well cleanout operations fluid in the annulus between the well casing and tubing is pressurized from the surface. This pressurized fluid, by virtue of the small diameter of the well tubing, typically coiled tubing, substantially increases in velocity as it enters the coiled tubing. This increased velocity fluid flow easily entrains and transports sand through the tubing to the surface for disposal.
As mentioned above, it is desirable to provide a controllable dual check valve tool to meet technical requirements and to provide for reverse circulating flow through the check valve mechanism as needed for well cleanout service and for other well service procedures. Referring now to
The upper end of the primary seal carrier fitting 46 defines an annular upwardly facing stop shoulder 64 that is disposed for movement limiting engagement with a downwardly facing annular shoulder 66 which is defined by an internally threaded extension 68 of a connector fitting 70 which receives an upper threaded section 72 of the inner tubular member 58. The connector fitting 70 is sealed to the inner tubular member 58 by an O-ring seal 74 and provides a connection between the check valve tool 28 and the coiled tubing 14. To ensure against inadvertent rotation of the connector fitting 70 with respect to the inner tubular member 58, and thus ensure retention of the dual check valve tool mechanism by the coiled tubing, a set screw or plug 76 is threaded through a hole in the connector fitting 70, with the inner end of the set screw or plug being received within a depression (typically a groove) or receptacle 71 within the upper end of the inner tubular member 58.
An annular chamber 78 is defined between the threaded extension 48 and the inner tubular member 58 and typically receives grease or any other suitable protective medium. A grease plug 80 is threaded into an opening of the primary seal carrier fitting 46 and is removable to permit grease to be introduced into the annular chamber 78.
A J-slot sleeve 82 is positioned in a portion of the annular chamber 78 between the tubular housing 36 and the inner tubular member 58 and defines an internal J-slot geometry which is depicted diagrammatically in
The lower housing section 40 defines an internal valve chamber 106 within which is received a tubular dual check valve mandrel or housing 108 that is seated on and positioned by a downwardly facing internal annular shoulder 110. The tubular dual check valve housing 108 provides pivotal support for a pair of swing check valve members 112 and 114 that are typically movable to the closed positions thereof responsive to upward or reverse circulating flow of fluid in addition to being spring biased closed by torsion springs surrounding hinge pins 115, thus blocking the upward flow of well fluid through the valve mechanism. The check valves 112, 114 are moved to open positions thereof responsive to downward or direct circulating flow of fluid, thus permitting injection of fluid into the well through the coiled tubing and the check valve mechanism.
For disabling the dual check valves 112, 114 of the check valve mechanism, a tubular lower section 116 is fixed to the inner tubular member 58 by interfitting tubular connector sections 118 and 120 of the inner tubular member 58 and the tubular lower section 116, thus defining a disconnect sleeve assembly. To disable the check valves and permit reverse circulating flow through the check valve mechanism, the inner tubular member 58 is moved to a position locating the lower tubular section 116 within the valve housing 108 as is evident from
When the dual check valve tool 28 is being pulled from the well or moved upwardly within a tubing string, the pulling force is applied by the coiled tubing to the inner tubular member 58 via the connector fitting 70, thus pulling the inner tubular member 58 to its uppermost position relative to the tubular housing 36 and thus moving the tubular lower section 116 to a position clear of the internal dual check valves, and enabling the check valves 112, 114 for the direct circulating flow mode. Thus the valve mechanism is always in the direct circulating flow mode during pulling of the reversible dual check valve tool from the well. The shear pins 122 provide for release of the tubular valve actuating element 116 from the inner tubular member 58 in the event of override conditions, for the purpose of restoring the check valve mechanism from a disabled or reverse circulation condition to an enabled flow responsive condition if needed. To the lower end of the tubular lower section 116 is mounted a ball seat fitting 126 by a threaded connection 128, with the fitting 126 being sealed to the tubular valve actuating element 116 by O-ring sealing element 130. Within the ball seat fitting 126 is seated a tubular ball seat element 132 having a spherical or tapered internal seating surface segment 134 that is engagable by a ball element, shown in broken line at 136, under override conditions. The tubular ball seat element 132 is sealed with respect to the tubular ball seat fitting 126 by a circular O-ring type sealing element 138. Within the lower housing section 40 of the tubular housing 36 is mounted a tubular connector and spacer element 140 by a threaded connection 142. Concentric spacing of the ball seat fitting 126 and the lower connection end 144 of the lower housing section 40 is maintained by an annular spacer section 146 which is sealed to the lower housing section 40 by an outer O-ring seal 148 and to the ball seat fitting 126 by an inner O-ring seal 150.
In the event the mechanism should become stuck in the reverse circulating flow mode and it becomes necessary to quickly enable the check valve mechanism for direct circulation only, a ball 136 is dropped into the flow passage of the coiled tubing and descends or is pumped to the ball seat 132, thus engaging the seat surface segment 134 and shutting off flow through the flow opening 151 of the ball seat fitting 126. With the ball 136 thus positioned, pressure is applied through the coiled tubing, thus imparting a downward force on the tubular lower section 116 of the inner tubular member 58. When this downward force exceeds the restraining force of the shear pins 122, the shear pins will be sheared and will release the lower tubular section 116 and permit the pressure induced downward force to move the valve actuating element downwardly past the internal annular O-ring seal 150, thus releasing the opening restraint of the check valves 112, 114 and enabling the check valve mechanism to function normally in direct circulating mode only. It should be borne in mind that the reverse circulating valve mechanism of the present invention cannot be run with a conventional check valve assembly above the tool. If a conventional check valve is used above the tool, it will prevent reverse fluid circulation.
A tubular drag spring support mandrel 154 is secured to the tubular connector and spacer element 140 by a threaded connection 156 and with a tubular guide nipple 158 being connected to the lower end of the tubular mandrel 154 by a threaded connection 160. The tubular guide nipple 158 defines a curved or tapered guide nose 162, also known as a “bull nose” which guides the tubular drag spring support mandrel 154 as the dual check valve tool 28 is run into the well. The bull nose 162 defines a fluid flow opening 164 through which fluid interchange to and from the reversible dual check valve tool occurs. The fluid flow opening 164 may comprise multiple small openings to prevent large debris from flowing up the coiled tubing. The bull nose 162 and the tubular drag spring mandrel 154 also define a chamber 155 within which the lower tubular section 116 is received when it is disconnected and displaced clear of the check valve housing as described above. The tubular drag spring support mandrel 154 is provided with upper and lower external stop members 168 and 170 which are chamfered and knurled to increase friction with the drag spring assemblies and prevent rotation of the tubular housing 36 during indexing rotation of the J-slot sleeve 82.
One or more drag spring assemblies, shown generally at 172, are located externally of the tubular drag spring support mandrel 154 and function to apply a restraining force to the tubular housing 36 as downward or upward force is applied via the tubing string or coiled tubing to the inner tubular member 58, and thus cause actuation of the J-slot indexing mechanism with which the reversible dual, selectively actuatable check valve mechanism is provided. The drag spring assembly or assemblies have one or more elongate leaf type spring elements 174 in the general form of a bow, with a central section 176 thereof projecting outwardly for frictional contact with the well tubing 21 or the well casing 20, as the case may be. Respective upper and lower end sections 178, 180 of the spring elements 174 are each connected with upper and lower drag shoe elements 182 and 184 which are each secured to the drag spring by retainer screws 186. The elongate drag springs 174 are designed with low radial spring rate to have acceptable friction with the tubing 20 while running the check valve tool 28 through a tubing string. The drag spring assemblies are linearly movable on the tubular drag spring support mandrel 154 within limits defined by the spacing of the drag shoe elements 182 and 184 and the spacing of the upper and lower stop members 168 and 170 of the tubular drag spring support mandrel 154. Retarding or restraining movement of the housing 36 within the tubing permits linear movement of the inner tubular member 58 relative to the housing 36 and permits incremental rotational movement of the J-slot sleeve 82 responsive to the differential force and consequently permits relative linear positioning of the inner tubular member at valve “Open” and valve “Enabled” positions relative to the tubular housing 36 as controlled by the J-slot indexing mechanism.
The reversible dual check valve tool shown in
Though
An inner tubular member 212 is located for linear movement within the housing structure 192 and is supported at its upper end by a guide and spacer fitting 214 having a spacer extension 216 that is connected with the upper end of the inner tubular member 212 by a threaded connection 218. The guide fitting 214 is statically sealed to the inner tubular member 212 by an O-ring seal 220 and is dynamically sealed with the inner cylindrical wall surface 222 of the upper housing section 194 by an O-ring seal 224. The fitting 214 also defines a tapered or conical guide surface 226 that serves to permit smooth flow of injected fluid into the inner passage 228 of the inner tubular member 212. The spacer extension 216 defines an annular spring support shoulder 230 which is engaged by the upper end of a compression spring 232 that is located within the annular space 234 or spring chamber that is defined between the upper housing section 194 and the inner tubular member 212. The lower end of the compression spring is seated on an annular spring support shoulder 236 that is defined by the upper end of the intermediate housing connector 200. Though a mechanical compression spring acts to return the inner tubular member and tubular housing to the condition permitting only direct circulation through the check valve mechanism, it should be borne in mind that the spring force may be applied by a compressed gas spring or any other such force transmitting element without departing from the spirit and scope of the present invention.
The concentric spacing of the inner tubular member 212 from the upper and lower housing sections that is achieved by the guide and spacer fitting 214 also defines an annular indexing chamber 238 within which is disposed a J-slot sleeve element 240 having upper and lower end portions 242 and 244 that are mounted for rotation within the indexing chamber 238 by upper and lower bearings 246 and 248. The J-slot sleeve element 240 defines internal grooves or slots that establish a J-slot geometry as shown by the J-slot layout view of
The valve housing section 198 is connected to the lower end of the lower housing section 196 by a threaded connection 252 and is sealed to the lower housing section by an O-ring seal 254. An annular valve chamber 256 is defined by the valve housing section 198 and receives a dual check valve assembly 258 having upper and lower check valves 260 and 262 that are shown to be in the form of pivotally mounted flapper type check valves that are shown in
An actuator housing 286 is secured to the lower end of the lower end section 276 by a threaded connection 288 and is sealed to the lower end section 276 by an O-ring seal 290. Within the actuator housing 286 is seated an annular override closure seat 292 having an annular tapered seat surface 294 for engagement by an override closure ball 296 that is shown in broken line. In the event override restoration of the direct flow mode of the valve mechanism is needed, an override closure ball is dropped into the tubing or coiled tubing string and injection pressure is applied. When the ball 296 becomes seated on the annular override closure seat 292, additional injection pressure will be applied to develop a downward force on the lower end section 276 to shear the shear pins 284, thus releasing lower end section 276 from the inner tubular member 212. The injection pressure will force lower end section 276 downwardly past the dual check valves 260 and 262 and into the receptacle 274, thus allowing the check valves to be closed by upward flow of fluid.
It is desirable to provide flow responsive upwardly and downwardly cycling actuation of the inner tubular member 212 and its lower end section 276. To accomplish this feature, an orifice fitting 298 is connected to the lower end of the actuator housing 286 by a threaded connection 300. The orifice fitting 298 defines an inner tapered seat surface 302 that is disposed for engagement by an actuator ball 304 that is maintained within an actuator chamber 306 by one or more internal ball retention elements 308. The internal ball retention elements 308 retain the actuator ball 304 within the actuator chamber 306 when upward flow is occurring, but do not establish sealing with the ball, thus permitting upward flow of fluid past the actuator ball, as shown by the flow arrows, when the actuator ball 304 is forced upwardly by fluid flow and is in retained engagement with the ball retention elements 308. The orifice fitting 298 also defines one or more orifice controlled flow passages 310, with changeable orifice inserts 312 threaded or otherwise secured therein. The orifice inserts 312 each define a flow passage orifice of a desired dimension to permit downward flow of fluid past the seated actuator ball and into the receptacle 274. This downward flow fluid will then flow through injection ports 314 in the closed lower end 315 of the tubular flow nipple 270.
Operation of Embodiment of
Responsive to downward flow of fluid through the coiled tubing and through the orifice controlled flow passage or passages 310, pressure differential will develop across the orifice inserts 312, and this pressure differential, acting on the piston area that is defined by the piston O-ring seal 224, less the orifice area 312 will develop a downwardly acting force on the inner tubular member 212, acting against the preload force of the compression spring 232. When this preload force is exceeded, the compression spring 232 will deflect and will allow downward movement of the inner tubular member 212 relative to the tubular housing 192. This flow responsive downward movement of the inner tubular member 212 causes the lower tubular section 276 of the inner tubular member 212 to move within the check valve assembly 258 as shown in
Typically, the dual check valve mechanism or tool will be run into the well with the check valves in their “Enabled” position, so that the check valve mechanism is enabled for its direct circulating mode. As shown in the J-slot layout illustration of
Referring now to
Operation of Embodiment of
This dual check valve and reversing valve tool embodiment utilizes fluid flow down the coiled tubing to actuate the J-slot indexing mechanism to the selective modes of the tool. The flow down the coiled tubing acts across an orifice to generate a pressure differential that acts on the effective piston area at 224 to generate a downward force. Once this (pressure times area) force exceeds the downward force of the compression spring plus seal and J-slot friction, the piston will move down. This will happen at a given repeatable flow rate (thus the name of the tool). In order to make the piston move down against the spring, a small orifice 346 (changeable orifice insert 344) is required, typically 0.375 inch (9.5 mm) diameter. When reversing sand up the coiled tubing, the pressure drop due to this orifice is undesirable. Thus the orifice is bypassed during reverse flow by a check valve. The check valve may be a ball, poppet or flapper type. A ball type check valve (actuating ball and seat) is shown due to its positive sealing and streamlining under reverse flow. The ball and seat can easily be made of tungsten carbide thus preventing erosion problems. The downstream pressure is channeled up the annulus of the tool between the housing and the mandrel to immediately below the piston area 224. This is why the orifice pressure differential acts on the effective piston area. If the orifice is axial, the effective piston area is the piston outer diameter area minus the orifice area. If the orifice is transverse, the effective area is the entire piston area.
It is desirable to provide a means for ensuring that the tool is in the reversing position by simply pumping down the coiled tubing using the bottom check valve at the lower end of the mandrel and using a lateral port which also serves as the orifice in the sleeve above the bottom check valve. The lateral port has a small gap or clearance for flow only in the pre-reversing position. This necessitates a sleeve that can be positioned rotationally to align in the proper manner over the ball seat sleeve at the bottom of the piston mandrel. The gap or clearance can be adjusted to accommodate varying flow rate settings.
The flow rate required for the orifice pressure differential to overcome the spring force with flow down the coiled tubing can be easily adjusted by changing the orifice and/or the spring. Typically this flow rate would be 0.5 to 3 barrels per minute (80 to 477 liters per minute). The example below uses 2 barrels per minute (318 liters per minute) as a flow rate where the orifice pressure has caused the mandrel to fully stroke to the down position (pre-reversing or pre-conventional).
In the absence of flow responsive pressure differential across the orifice 346, the preload force of the compression spring 232 will position the inner tubular member 212 at its uppermost position within the housing 192, thus positioning the lower end section 276 and its actuator housing above the dual check valves and enabling the valve mechanism for direct circulation flow only. Upward, i.e., reverse flow of fluid through the valve mechanism will be prevented by closure of the dual check valves 260 and 262. To position the valve mechanism for both direct circulation and reverse circulation, injection pressure through the coiled tubing and valve mechanism is initiated, causing the flow control ball 356 to seat on the annular seat surface 354 of the ball seat fitting and preventing downward flow of fluid through the flow passage 355. Thus, downward flow of fluid from the coiled tubing will occur only through the orifice 346 of the orifice insert 344, thereby developing a pressure differential across the orifice and a resultant pressure differential induced downward force on the inner tubular member 212 that will act on the compression spring 232. When the preload force of the compression spring has been overcome, the pressure differential induced downward force will move the inner tubular member downwardly, causing the J-pin 251 to track downwardly within an elongate substantially straight guide track 253, shown in
In the event of override conditions requiring immediate restoration of the valve mechanism to direct circulation only, injection pressure may simply be increased sufficiently to develop differential pressure across the orifice so that a downward resultant force on the inner tubular member 212 is sufficiently great that the disconnect shear pins 284 will be sheared. When the lower end section 276 and the actuator housing 334 are disconnected from the inner tubular member 212, downward fluid flow will move these components downwardly past the dual check valves and into the receptacle 274. As injection flow is diminished, the well fluid, flowing upwardly, will move the check valves to their closed positions, isolating the tubing string from well pressure. Alternatively, a ball 296 may be dropped or pumped through the coiled tubing to obstruct the annular seat 294 causing pressure to shear the shear pins 284.
Referring now to
The dual check valve selective direct and reverse circulating valve tool 360 has a housing assembly, shown generally at 362 being defined by an upper housing section 364 that is secured by a threaded connection 366 to a valve housing section 368. The upper housing section 364 is sealed to the valve housing section 368 by an O-ring seal 370. A tubular flow nipple 372, also referred to as a bullnose, is secured to the lower end of the valve housing section 368 by a threaded connection 374 and is sealed therewith by an O-ring seal 376. The tubular flow nipple 372 defines an internal chamber 373 and is provided at its lower closed and rounded end 378 with flow passages 380 through which fluid is injected into the well and through which reverse flow from the well is permitted to occur when the dual check valve mechanism is selectively actuated to permit reverse fluid circulation. The internal chamber 373 is of sufficient length to receive the lower tubular end of the inner tubular member when an override procedure occurs as discussed below.
An inner tubular member 382 is linearly movable within the housing assembly, with its upper end 384 having threaded connection at 386 within a connection collar fitting 388. Tubing 390, such as coiled tubing, is also received within and establishes a threaded connection at 392 with the connection collar fitting 388. O-ring seals 394 and 396 accomplish sealing of the tubing and the inner tubular member with respect to the connection collar fitting. To prevent relative rotation of the connection collar fitting 388 and the inner tubular member 382 when the tool is within the tubing of the wellbore, an anti-rotation screw 398 is threaded through the connection collar fitting and engages a groove in the upper end 384 of the inner tubular member. The inner tubular member 382 is provided intermediate its extremity with an externally projecting boss 383 which may be integral with the inner tubular member or may be welded or otherwise fixed to the inner tubular member. From the externally projecting boss 383 projects a J-pin element 385.
The connection collar fitting 388 defines an annular force transmitting shoulder 400 that is engaged by the upper end of a compression spring 402 that is located externally of the inner tubular member 382. The lower end of the compression spring 402 is seated on an annular shoulder 404 of a housing closure fitting 406 that is connected into the upper internally threaded end of the upper housing section 364 at a threaded connection 408. An O-ring seal 410 establishes sealing of the housing closure fitting 406 with the upper housing section 364 and an O-ring seal 412 establishes dynamic sealing of the housing closure fitting 406 with the external cylindrical surface 414 of the inner tubular member 382. The threaded projection 416 of the housing closure fitting 406 also serves as a spacer to establish a spaced relation between the housing assembly 362 and the inner tubular member 382, thus defining an annular chamber 418 within which is located an elongate tubular J-slot sleeve 420. Upper and lower bearings 422 and 424 provide rotatable support for the elongate tubular J-slot sleeve 420 within the chamber 418 and thus provide for its rotation within the chamber 418 for indexing of the valve mechanism to its direct circulation mode and to its reverse circulation mode. The threaded projection 416 defines a downwardly facing shoulder 426 that engages and positions the upper bearing 422 while the lower bearing 424 is seated on a support shoulder 428 that is defined within the lower portion of the upper housing section 364.
The internal surface of the generally cylindrical J-slot sleeve defines an indexing slot geometry which is shown in detail by the J-slot layout illustration of
An externally threaded projection 365 on upper housing section 364 serves a spacing function to position the inner tubular member 382 in spaced relation with the upper housing section 364 and the valve housing section 368 and defines a valve chamber 430. A dual check valve assembly 432 is located within the valve chamber 430 and is provided with a pair of check valve elements 434 and 436 that are preferably of the swing or flapper type, but may be ball, poppet or any other type of suitable check valves within the spirit and scope of the present invention.
A tubular lower end section 438 of the inner tubular member 382 is connected to the inner tubular member by a disconnect connection that is defined by engaging connection sleeves 440 and 442 of the inner tubular member 382 and the tubular lower end section 438 which are secured in releasable assembly by one or more shear pins 444 and are maintained in sealed assembly by an O-ring seal 446. The tubular lower end section 438 functions as a valve actuator to open and maintain the check valves 434 and 436 open in order to permit reverse circulation flow and direct circulation flow to occur. The valve open, or reverse circulation condition of the tool is shown in
A tubular valve seat retainer fitting 448, which defines the lower end of the tubular lower end section 438 is threaded to the tubular lower end section at 450 and sealed by an O-ring seal 452. The tubular valve seat retainer fitting 448 defines an upwardly facing seat shoulder 454 on which a tubular ball seat 456 is seated. The tubular ball seat 456 defines a circular ball seat surface 458 against which an override ball, shown in broken line at 460, becomes seated in the event an override procedure should become necessary. The override ball is dropped through the well tubing and comes to rest on the seat surface 458 when an override procedure is needed. With the override ball 460 so seated, pressure is applied to the tubing from the surface, thereby developing a downward pressure responsive force on the override ball and seat and causing shearing of the shear pin or pins 444 and accomplishing a disconnect of connection sleeves 440 and 442 and allowing the pressure induced force on the override ball and the tubular lower end section 438 to move the tubular lower end section downward into the chamber 373 of the tubular flow nipple 372 and clear of the check valves, thus enabling the check valves for direct circulation only.
Operation of Embodiment of
Operation of the tool mechanism of
The tool is moved downwardly within the well until the lower rounded bullnose 378 at the lower end of the tubular flow nipple 372 comes into contact, i.e., tags the fill, typically sand, within the well casing, at which point downward movement of the housing assembly 362 will stop. As further downward mechanical force is applied via the tubing string to the connection collar fitting 388 and the inner tubular member 382, the preload force of the compression spring 402, i.e., about 500 pounds (227 kg), will be overcome and the inner tubular member 382 will begin to move downwardly relative to the housing assembly 362. Referring to
From the “Indexing” position of the J-pin, reduction of the downward force acting on the inner tubular member 382 will permit the compression spring 402 to move the inner tubular member 382 upwardly relative to the housing assembly 362, causing the J-pin 385 to move upwardly within the slot section 429. During such upward J-pin movement it will contact the inclined sidewall 431 of inclined slot section 433, with its upwardly directed force causing further rotation of the J-slot sleeve 420 until the slot section 435 is encountered. Upward movement of the J-pin 385 and thereby the inner tubular member 382 occurs responsive to the force of the compression spring 402, the upward movement of the J-pin will proceed to the “Open” position. At this “Open” position of the J-pin, the check valves will be retained open and both direct and reverse circulation through the valve mechanism will be permitted.
Sequencing of the indexing mechanism and thus the valve mechanism back to its “Enabled” position will occur by simply again applying downward force on the inner tubular member from the “Open” position to cause rotation of the J-slot sleeve another rotational increment to permit the J-pin to encounter another elongate, substantially vertically oriented slot section such as that shown at 421 in
In view of the foregoing it is evident that the present invention is one well adapted to attain all of the objects and features hereinabove set forth, together with other objects and features which are inherent in the apparatus disclosed herein.
As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its spirit or essential characteristics. The present embodiments are, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein.
This application claims priority from U.S. Provisional Application 60/399,255, filed Jul. 29, 2002, which is incorporated herein by reference.
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| Number | Date | Country | |
|---|---|---|---|
| 60399255 | Jul 2002 | US |
