Downhole multi-action jetting tool

Abstract

An apparatus for cleaning a wellbore casing includes an outer housing having an axial through passage between an inlet and a first outlet wherein the inlet and the first outlet are adapted for connection in a work string, the outer housing having a second outlet extending in a direction generally transversely of the through passage, an index mandrel slidably located within the outer housing and having an axial bore extending therethrough, the index mandrel being movable relative to the outer housing between a first position in which the second outlet is closed and a second position in which the second outlet is open, a ball seat located on an upper end of the index mandrel, a spring located within the outer housing and biasing the index mandrel toward the first position, a ball retainable on the ball seat to prevent flow from the inlet to the first outlet, and wherein application of a first pressure on the ball forces the index mandrel against the spring into the second position and reduction of said first pressure permits return of the index mandrel to the second position.

Description

BACKGROUND OF INVENTION

A wellbore may be drilled in the earth for various purposes, such as hydrocarbon extraction, geothermal energy, or water. After a wellbore is drilled, the wellore is typically lined with casing. The casing preserves the shape of the wellore as well as provides a sealed conduit for fluid to be transported to the surface.

In general, it is desirable to maintain a clean wellore to prevent possible complications that may occur from debris in the wellore. For example, accumulation of debris can prevent free movement of tools through the wellore during operations, as well as possibly interfere with production of hydrocarbons or damage tools. Potential debris includes cuttings produced from the drilling of the wellore, metallic debris from the various tools and components used in operations, and corrosion of the casing. Much of this debris may be removed by increasing the annular fluid velocity to bring larger particles to the surface of the wellbore.

However, over time, the casing or liner within the wellbore becomes covered with hard deposits. These deposits must be periodically removed or they can build up to levels of thickness and hardness where they can adversely affect efficient operation of the oil well.

Many tools operate continuously through a wellbore, for example scrapers and brushes. While it is useful to have such continuous use tools, it is often beneficial to have tools that are selectively operable when the tool has reached a preferred location in the wellbore.

Cleaning involves spraying or jetting the inner wall of the casing with cleaning fluid at very high pressure to break up and dislodge the deposited material. A cleaning device having side jetting nozzles is lowered into the wellbore casing on the end of a drill string. Once a section of the wellbore casing has been jet cleaned, the cleaning device is withdrawn from the wellbore casing and removed from the end of the string. The drill string is then returned to the wellbore casing and cleaning fluid is run through the casing to a point below the section of the wellbore casing that was jet cleaned. The cleaning fluid circulates upward through the annulus between the wellbore casing and the drill string, carrying material dislodged during the jetting operation to the top of the wellbore casing. This operation of jetting and flushing is repeated as necessary to clean the wellbore casing of deposited material. Many cleaning and jetting tools use multiple balls to actuate and de-actuate the tool. It would be an improvement to have a cleaning tool that can be actuated and de-actuated without the need to use multiple balls.

SUMMARY

In one aspect, the disclosed invention relates to an apparatus for cleaning a wellbore casing including an outer housing having an axial through passage between an inlet and a first outlet wherein the inlet and the first outlet are adapted for connection in a work string, the outer housing having a second outlet extending in a direction generally transversely of the through passage, an index mandrel slidably located within the outer housing and having an axial bore extending therethrough, the index mandrel being movable relative to the outer housing between a first position in which the second outlet is closed and a second position in which the second outlet is open, a ball seat located on an upper end of the index mandrel, a spring located within the outer housing and biasing the index mandrel toward the first position, a ball retainable on the ball seat to prevent flow from the inlet to the first outlet, and wherein application of a first pressure on the ball forces the index mandrel against the spring into the second position and reduction of said first pressure permits return of the index mandrel to the second position.

In another disclosed embodiment of the invention, a method of cleaning an inner surface of a casing in a wellbore includes lowering a jetting tool on a work string into the wellbore to a desired location, wherein the jetting tool has an outer housing with an axial through passage between an inlet and a first outlet, the outer housing also having a second outlet substantially transverse to the axial through passage, and an index housing slidingly retained within the outer housing in a first position such that the second outlet is closed, the index housing having a ball seat on an upper end and being biased toward the first position, dropping a ball into the axial through passage to rest on the ball seat, thereby preventing fluid flow between the inlet and the first outlet of the axial through passage, causing fluid pressure to force the index housing to a second position wherein the second outlet is open, circulating fluid from the axial through passage and the second outlet at a fluid pressure sufficient to clean the casing, decreasing the fluid pressure to return the index housing to the first position, increasing the fluid pressure to move the index housing to a third position wherein the second outlet is closed, and wherein the increased fluid pressure is sufficient to shear the ball from the ball seat, thereby reducing the fluid pressure on the index housing causing it to return to the first position.

In another embodiment of the disclosed invention, a method of opening and closing an outlet through a side of a cylindrical outer housing of a jetting tool in a wellbore includes biasing the index housing to an upward position within the outer housing in which the index housing is blocking the fluid outlet through the side of the outer housing, dropping a ball to seal against a ball seat located at the upper end of the index housing and block fluid flow through the jetting tool, forcing the index housing to a lower position inside the outer housing as a result of increased pressure behind the ball, wherein the fluid outlet through the side of the outer housing is open, reducing the fluid pressure on the ball to permit the biasing of the index housing towards the upward position, wherein the fluid outlet through the side of the outer housing is closed, and increasing the fluid pressure on the ball to a pressure sufficient to shear the ball through the ball seat, thereby permitting the index housing to return to the upward position.

Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an embodiment of a well cleaning tool.

FIG. 2 is a front view of an embodiment of a well cleaning tool.

FIG. 3 is a detail cross sectional view of an embodiment of a well cleaning tool.

FIG. 4 is a layout of an embodiment of an indexing groove.

FIG. 5 is a schematic of a well cleaning tool in a first, run-in-hole, position.

FIG. 6 is a schematic of a well cleaning tool in a second, jetting, position.

FIG. 7 is a schematic of a well cleaning tool in a third, intermediate, position.

FIG. 8 is a schematic of a well cleaning tool in a fourth, ball shear, position.

FIG. 9 is a partial cross sectional view of the downhole bypass valve in a first run in position.

FIG. 10 a is a partial cross sectional view of the indexing pin and surrounding components.

FIG. 10 b is a partial cross sectional view of a port and a bonded seal member.

FIG. 10 c is a partial cross sectional view of a collet assembly.

FIG. 11 is a partial cross sectional view of the downhole bypass valve in the first position with the ball actuator.

FIG. 12 is a partial cross sectional view of the downhole bypass valve in a second position.

FIG. 13 is a partial cross sectional view of the downhole bypass valve in a third position.

FIG. 14 is a partial cross sectional view of the downhole bypass valve in a fourth position.

FIG. 15 is a layout of the indexing groove.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a downhole jetting tool 100 that may be used to selectively divert fluid that is flowing down the drill string bore 102 to the annulus 104 between the drill string and the casing 106 of a wellbore 108. The jetting tool 100 includes an outer housing 110 and a spring-loaded index mandrel 168 defining a tubular assembly having an inlet 206 and a first outlet 208.

The outer housing 110 defines an axial through passage 124 within which the index housing 168 is located. The outer housing 110 has a top sub 126 provided at a top end 112, wherein the top sub 126 includes a threaded box 114 to couple to an upper drill string component (not shown). The top sub 126 has one or more radially extending ports 132 extending from the axial through passage 124 to the annulus 104, collectively defining a second outlet 128. The top sub 126 is coupled to a swivel housing 116 for the index housing 168 at a lower end 130. The coupling of the swivel housing 134 and the top sub 126 provides an upper shoulder 138 at the lower end 136 of the top sub 126. A lower shoulder 140, formed in the swivel housing 116, is spaced apart from the upper shoulder 136 to form an inner recess 142 within which a swivel ring 144 is retained. The swivel ring 144 includes at least one indexing pin 146 extending radially into the axial through passage 124 defined by the outer housing 110. While the swivel ring 144 is axially retained by the upper and lower shoulders 138, 140, the swivel ring 144 is not rotationally retained to the outer housing 110. Thus, the swivel ring 144 may rotate within the confines of the upper and lower shoulders 138, 140. Along a middle portion 150 of the swivel housing 116, a spring housing 152 is coupled thereto. A lower portion 154 of the swivel housing 116 protrudes axially within a through bore 156 defined by the spring housing 152. The lower portion 154 of the swivel housing 116 is spaced apart from the corresponding portion of the spring housing 152 such that a small gap 162 is created. Within this small gap 162, a spring sleeve 162 is coupled to the spring housing 152. As will be explained below, the spring sleeve 164 is included primarily to aid in the assembly and disassembly of the jetting tool 100. The spring housing 152 is provided with external threads 120 at lower end 118 to coupled to a ball catcher 122 or another lower drill string component (not shown).

As previously stated, the index housing 168 is located within the outer housing 110. The index housing 168 includes an indexing mandrel 170 coupled at a lower end 172 to a collet blank 174 to define a mandrel through passage 176. The through passage 176 has a mandrel bore radius 178. The indexing mandrel 170 has a ball seat 148 sealingly coupled at a top end 158. An o-ring 166 may be included to seal the interface between the ball seat 148 and the index mandrel 170. Other sealing means known in the art may be used. The ball seat 148 includes a lower shoulder 186, which rests against top end 158. A frustroconical section 188 at the top of the ball seat 148 provides a guide to direct a ball 250 (the ball 250 and related features are shown in FIGS. 5-8) through the center of the through passage. A landing section 190 projects generally inward at the bottom 194 of the ball seat 148. The landing section 190 projects inward a sufficient distance and angle to seat the ball 250 as will be described. The radius 240 of the landing section 190 is thus smaller than the ball radius 252. A seal member 180 is located above a shoulder formation 182 in the outer surface 184 of the indexing mandrel 170 and below the lower shoulder 186 of the ball seat 148. Below the shoulder formation 182, a recess 202 is formed in the outer surface 184 of the indexing mandrel 170. An o-ring 204 or other sealing member seals the interface between the outer surface 184 of the indexing mandrel 170 and the inner surface 192 of the top sub 126 below the recess 202.

An indexing groove 200 is formed into the outer surface 184 of the indexing mandrel 170 between the o-ring 204 and a lower end 172 of the indexing mandrel 170. The indexing pin 146, coupled to the outer housing 110, is positioned within the indexing groove 200. The function of the indexing groove 200 and the indexing pin 146 is described in greater detail below.

A spring assembly 210 includes the collet blank 174, a spring follower 214 and a spring 216. As was previously described, the collet blank 174 couples to the index mandrel 170. The spring 216 is located within the through passage 156 defined by the spring housing 152. A shoulder formation 218 in the inner surface 220 of the spring housing 152 near the lower end 118 provides support to a lower end 222 of the spring 216. The spring follower 214 has a lower shoulder 224 that is seated atop an upper end 226 of the spring 216. The collet blank 174 has a lower end 228 that is seated atop an inner shoulder 230 of the spring follower 214 such that the lower end 228 of the collet blank 174 is within the spring follower 214.

The ball 250 will be used to actuate the jetting tool 100. The ball 250 will be dropped from the top of the work string and allowed to float downward through the fluid in the axial through passage 124 until it reaches the ball seat 148. Thus, the ball 250 is formed from a material having a specific gravity greater than fluid though which it will be dropped. Further, the ball 250 must be made from a material that will not be degraded by the chemical composition of the fluid in axial though passage 102. Also, when the jetting tool 100 no longer needs to be cycled, the ball 250 can be sheared through the ball seat 148 by increasing the fluid pressure through the axial through passage 102. Thus, the ball 250 is also formed from a material that will deform under a predetermined minimum pressure. For example, in one embodiment, the ball is made from a thermoplastic polyester based on polyethylene terephthalate, such as ERTALYTE (™).

When the jetting tool 100 is assembled, the spring 216 is lowered into the spring housing 152 and the spring follower 214 is placed atop the spring 216. The swivel housing 116 couples to the spring housing 152. However, the length of the spring 216 when loaded only with the spring follower 214 would extend beyond the lower end 160 of the lower portion 154 of the swivel housing 134 when the swivel housing 116 is coupled to the spring housing 152. Instead of loading the spring 216 with the swivel housing 116 while coupling to the spring housing 152, the spring sleeve 164 is coupled to the spring housing 152 to preload the spring 216, through the spring follower 214, against a lower shoulder 166. The smaller size of the spring sleeve 164 makes it easier to couple to the spring housing 152 while simultaneously preloading the spring 216. The larger swivel housing 134 may then be simply coupled to the spring housing 152. When disassembling the jetting tool 100, the spring sleeve 164 retains the spring 162 and spring follower 214 within the spring housing 152 while the swivel housing 116 is removed.

In one embodiment a jetting housing 196 is provided around the bypass valve 100. The jetting housing 196 displaces annular space when the bypass valve 100 is to be used in a bore, such as that of a riser, having a sufficiently large inner diameter that annular fluid velocity would be lost if the jetting tool 100 were used without the jetting housing 196. By reducing the annular area, fluid velocity through the second outlet 132 into the annulus 104 may be maintained at a rate that is effective for removing debris or circulating fluid. Jetting housings 196 having different outer diameters may be available and the choice of size is typically based upon the diameter of the casing to be cleaned. Referring to FIGS. 2 and 3, the jetting housing 196 includes a plurality of jetting ports 198. When the second outlet 128 is open, the jetting ports 198 focus a stream of fluid toward the casing 106 of the wellbore 108 in a direction substantially perpendicular to the axial through passage 124. As the fluid exits the jetting ports 198, the direction of the stream of fluid will be affected by fluid circulation in the annulus 104 fluid pressure in the annulus 104, as well as the geometry of the jetting port exits. While the fluid is directed toward the casing 106, it will be appreciated by a person of skill in the art that the fluid direction will not be precisely pointed at a point on the casing, but rather a general area of the casing 106. In one embodiment, the jetting housing 196 includes a plurality of tangent jetting ports 212, as can be seen in FIG. 3. Tangent jetting ports 212 direct fluid flow in a direction substantially tangent to the flow of fluid out of the jetting ports 198. As with the jetting ports 198, fluid flow out of the tangent jetting ports 212 is affected by a variety of factors including fluid circulation in the annulus 104 fluid pressure in the annulus 104, as well as the geometry of the tangent jetting port exits. In one embodiment, the jetting housing 196 is rotationally retained on the outer housing 110. In one embodiment, tangent jetting ports 212 rotate the jetting housing 196 about the outer housing 110.

When lowered downhole on the drill string, the jetting tool 100 is in a first position, as depicted in FIGS. 1 and 5. In this position, the recess 202 of the indexing mandrel 170 is positioned inside the second outlet 128. As depicted in FIG. 1, the seal ring 180 is located above the second outlet 128 while the o-ring 204 is positioned below the second outlet 128 to prevent fluid communication between the through passage 176 and the annulus 104. Returning to FIGS. 1 and 5, fluid may continue to flow through the through passage 176 defined by the index housing 168 and the through passage 156 defined by the spring housing 152.

Referring to FIG. 6, when it is desired to actuate the jetting tool 100, a ball 250 is dropped through the drill string and circulated until it reaches the jetting tool 100. The ball 250 has a ball radius 252, which is less than the outer housing radius 232 and greater than the landing section radius 240, thus permitting the ball 250 to continue to circulate through the jetting tool 100 until it comes to rest atop the landing section 190. The ball 250 prevents further fluid flow through the bore 238, 156 of the index housing 168, spring 216, and spring housing 152. As the fluid pressure is increased, the ball seat 148 and index housing 168 are pushed downward against the upward force of the spring 216. The indexing groove 200 on the indexing mandrel 170 interfaces with the indexing pin 146 to direct the position of the indexing mandrel 170 within the outer housing 110.

The indexing groove path 262 is depicted in FIG. 4. When the jetting tool 100 is in the first position, the indexing pin 146 is located in a first groove location 260. Referring to FIG. 6, after the ball 250 is seated on the ball seat 148, fluid pressure is increased until the ball seat 148 and indexing mandrel 170 are driven downward against the force of the spring 216. As the indexing mandrel 170 moves downward within the outer housing 110, the indexing pin 146 follows the indexing groove path 262 until it has reached a first groove wall 264. Upon contacting the first groove wall 264, the indexing pin 146 continues a path parallel to the first groove wall 264 until it has shouldered against second groove location 266. The outer housing 110 is rotationally fixed by the drill string. The swivel ring 144 is rotated within the outer housing 110 as the indexing pin 146 follows the indexing groove path 262. When the indexing pin 146 is shouldered against the second groove location 266, the jetting tool 100 is in a corresponding second position, shown in FIG. 6.

In the second position, the ball 250 remains seated atop the landing section 190 of the ball seat 148. The indexing mandrel 170 and ball seat 148 have moved a sufficient distance downward to open the second outlet 128, providing fluid communication from the through passage 124 to the annulus 104. So long as the fluid flow remains sufficient to provide pressure to the ball 250 and the index housing 168 to overcome the upward force of the spring 216, the jetting tool 100 will remain in the second position.

Referring to FIGS. 6 and 7, when the flow drops to below a predetermined flow rate corresponding to a predetermined fluid pressure, the spring 216 will push the index housing 168 upward. The indexing pin 146 continues to follow the indexing groove path 262 and contacts a second groove wall 268. The indexing pin 146 follows the incline of the second groove wall 268 to position the indexing mandrel 170 within the outer housing 110. The indexing mandrel 170 continues to move upward until the indexing pin 146 shoulders against a third groove location 270. When the indexing pin 146 is in the third groove location 270, the jetting tool 100 is in a corresponding third position, shown in FIG. 7.

In the third position, the ball 250 remains seated atop the landing section 190 of the ball seat 148. The second outlet 128 is closed, resulting in no fluid communication from the through passage 124 to the annulus 104 and no flow through the through passage 124 to the first outlet 208.

The fluid pressure may be increased to cycle the indexing mandrel 170 to a fourth position, in which the indexing pin 146 is shouldered against a fourth groove location 272 longitudinally located along the indexing mandrel 170 between the second groove location 266 and the third groove location 270. So long as the fluid pressure does not exceed a predetermined pressure sufficient to deform the ball 250, decreasing the fluid pressure again will return the indexing mandrel 168 to the third position, wherein the indexing pin 146 is shouldered against another third groove location 270. Increasing pressure when the ball 250 is in the third position for the second time will return the indexing mandrel 170 to a second position in which the second outlet 128 is open. This cycle may be continued until the indexing pin 146 has traversed the indexing groove path 262 any number of times.

When the jetting operation is completed, the jetting tool 100 is cycled by increasing and decreasing fluid pressure on the ball 250 until the indexing pin 146 is again in the fourth groove location 272. The pressure may then be increased to a predetermined pressure sufficient to shear the ball 250 through the bottom 194 of the ball seat 148, as shown in FIG. 8. The ball 250 is then forced downward through the through passage 238 of the index housing 168 and the through passage 156 of the spring housing 152. The ball 250 is caught in a downstream ball catcher 122. When the ball 250 is released from the ball seat 148, the fluid pressure counteracting the spring force is relieved and the spring 216 pushes the index housing 168 and the ball seat 148 upward. The indexing groove 200 and pin 146 interact to reposition the indexing mandrel 170 in the first position in which the second outlet 128 is closed and from which the entire process may be performed again.

Referring to FIG. 1, the ball catcher 122 includes a ball catcher sub 234 within which a ball catcher tube 236 is retained. A trap finger 238 is provided near the top end 242 of the ball catcher tube 236. The top end 242 of the ball catcher tube 236 may be provided with slots 276. The trap finger 238 is pivotally retained to the ball catcher tube 236 near the top end 242 along a pivot edge 244. A torsion spring 246 biases the trap finger 238 toward a “closed” position. As shown in FIG. 1, a free edge 248 is rotatable within the ball catcher sub 234. The trap finger 238 has a length 254 such that the trap finger 238 free edge 248 can travel through slot 276 and is caught on an edge of the slot 276 before opening in an upward position. A stopper 178 may be included near the free edge 248 to aid in catching the slot edge before over-traveling. When the ball 250 is discharged from the ball seat 148, the ball 250 pushes the free edge 248 downward and enters the ball tube 236. Once the ball 250 has cleared the trap finger 238, the torsion spring 246 moves the trap finger 238 back to the closed position.

The ball catcher tube 236 has an outer diameter less than the inner diameter of the ball catcher sub 234, defining a ball catcher annulus 274. The ball catcher tube 236 is also provided with a number of holes 258 though the wall of the tube 236 providing fluid communication from the though passage of the ball catcher tube 236 to the ball catcher annulus 274. If reverse circulation is desired, the holes 258 and ball catcher annulus 274 allow fluid flow around any balls 250 retained in the ball catcher tube 236 and to the tools above the ball catcher 122. Any balls 150 in the ball catcher tube 236 that are forced upward by the reverse circulation are retained by the trap finger 238. Any force on the trap finger 238 by retained balls 250 will reinforce the force of the torsion spring 246 in pushing the free edge 248 against the slot edge of the ball catcher tube 236, thereby preventing the loss of balls 250 from the ball catcher 122. The ball catcher tube 236 may be sized to accommodate any number of balls 250. For example, in one embodiment, the ball catcher tube 126 holds six balls 250.

The jetting tool 100 can be used to clean the inner surface of a casing and/or a blowout preventor (BOP). To perform a cleaning operation, the jetting tool 100 is assembled on a work string and lowered into the wellbore 108 to a location to be cleaned. The index housing 168 is in a first position relative to the outer housing 110, as shown in FIG. 5, and the second outlet 128 through the outer housing 110 is closed off by the index housing 168. The ball 250 is dropped into the axial through passage 102 of the work string and is circulated through the work string until the it reaches the ball seat 148 of the jetting tool 100. When the ball 150 reaches the ball seat 128, it is directed to a landing section 190 where it prevents fluid from flowing through the index housing 168 and spring housing 152 as well as the lower work string tools (not shown). Fluid continues to be pumped at a predetermined rate into the through passage 102 of the work string, thereby applying pressure to the ball 250. This pressure works against the upward force of the spring 216. As the pressure on the ball 250 increases, the index housing 168 is lowered relative to the outer housing 110 until the index housing 168 reaches a second position, shown in FIG. 6. When the index housing 168 is in the second position, the second outlet 128 through the outer housing 110 is open. The fluid that is being pumped into the axial through passage is then directed through the second outlet 128 and the jetting ports 198 at a pressure sufficient to clean the casing and/or BOP. The jetting tool 100 may be rotated by rotating the work string to direct fluid flow from the jetting ports 198 at a circumferential area of the casing or BOP. The jetting tool 100 may be raised and/or lowered by raising and/or lowering the work string to direct flow from the jetting ports 198 at a longitudinal area of the casing or BOP. As previously discussed, the jetting housing 196 may be rotationally retained on the outer housing 110 and tangential jetting ports 212 utilized to rotate the jetting housing 196 to clean a circumferential area of the casing and/or BOP.

When a location of the casing and/or BOP has been cleaned, fluid pressure through the axial through passage 124 may be reduced. As the pressure is reduced to a pressure insufficient to overcome the spring force, the spring 216 pushes the index housing 168 upward relative to the outer housing 110 to a third position, shown in FIG. 7. The second outlet 128 through the outer housing 110 is closed when the index housing 168 is in the third position.

The pressure may be increased again to a predetermined pressure that is sufficient to overcome the spring force but that is insufficient to deform the ball 250. This drives the index housing 168 to a fourth position. From the fourth position, the fluid pressure may be decreased again so that the spring 216 forces the index housing 168 into another first position. Increasing the pressure from this third position will force the index housing 168 into another second position in which the second outlet 128 is again open and additional cleaning activities may be performed. If such additional cleaning activities are not desired, from the fourth position, the fluid pressure may be increased by an additional amount sufficient to shear the ball 250 from the ball seat 148. When the ball 250 has been sheared from the ball seat 148, the spring 216 will force the index housing 168 into another first position and the jetting tool may be re-actuated by dropping another ball 250. The sheared ball 250 is circulated through the remainder of the jetting tool 100 and is caught by the ball catcher 122. As previously discussed, if recirculation of the fluid is desired, the ball catcher 122 will retain any sheared balls 250 previously caught in the ball catcher 122.

Referring to FIG. 9, in another embodiment, a downhole bypass valve 300 is used to selectively divert fluid that is flowing down the drill string bore 302 to the annulus 304 between the drill string and the casing 306 of a wellbore 308. The bypass valve 300 includes an outer housing 310, a spring-loaded mandrel 368, and a cantilever-type ball seat collet assembly 410 defining a tubular assembly having an inlet 406 and a first outlet 408.

The outer housing 310 defines an outer housing through bore 324 within which the spring-loaded mandrel 368 and the collet assembly 410 are located. The outer housing 310 has a top sub 326 provided at a top end 312, wherein the top sub 326 includes a threaded box 314 to couple to an upper drill string component 316. The top sub 326 is coupled to a ported seal housing 328 at a lower end 330. The ported seal housing 328 has one or more radially extending ports 332 extending from the outer housing through bore 324 to the annulus 304, defining a second outlet. A swivel housing 334 is coupled to a lower end 336 of the ported seal housing 328. As shown more clearly in FIG. 10a, the coupling of the swivel housing 334 and the ported seal housing 328 provides an upper shoulder 338 at the lower end 336 of the ported seal housing 328. A lower shoulder 340, formed in the swivel housing 334, is spaced apart from the upper shoulder 336 to form an inner recess 342 within which a swivel ring 344 is retained. The swivel ring 344 includes at least one indexing pin 346 extending radially into the through bore 324 defined by the outer housing 310. While the swivel ring 344 is axially retained by the upper and lower shoulders 338, 340, the swivel ring 344 is not rotationally retained to the outer housing 310. Thus, the swivel ring 344 may rotate within the confines of the upper and lower shoulders 338, 340. Returning to FIG. 9, along a middle portion 350 of the swivel housing 334, a spring housing 352 is coupled thereto. As shown more clearly in FIG. 10c, a lower portion 354 of the swivel housing 334 protrudes axially within a through bore 356 defined by the spring housing 352 and has a recess formation 358 in an inner surface 359 at its lower end 360. The lower portion 354 of the swivel housing 334 is spaced apart from the corresponding portion of the spring housing 352 such that a small gap 362 is created. Within this small gap 362, a spring sleeve 362 is coupled to the spring housing 352. As will be explained below, the spring sleeve 364 is included primarily to aid in the assembly and disassembly of the bypass valve 300. Returning again to FIG. 9, the spring housing 352 is provided with external threads 320 at lower end 318 to couple to a lower drill string component 322.

As previously stated, the spring-loaded mandrel 368 is located within the outer housing 310. The spring-loaded mandrel 368 includes an indexing mandrel 370 coupled at a lower end 372 to a shoulder sub 374 to define a mandrel through bore 376. As shown in FIG. 10b, the through bore 376 has a mandrel bore radius 378. A bonded seal member 380 is located above a shoulder formation 382 in the outer surface 384 of the indexing mandrel 370. A retaining ring 386 may be secured to the indexing mandrel 370 such that it is spaced apart from the shoulder formation 382 to maintain the bonded seal member 380 in a position near the upper end 387 of the indexing mandrel 370. The bonded seal member 380 includes a pair of resilient outer seals 388, 390, which seal the interface between the inner surface 392 of the ported seal housing 328 and the outer surface 394 of the bonded seal member 380. An o-ring 396 seals the interface between an inner surface 398 of the bonded seal member 380 and the outer surface 384 of the indexing mandrel 370. Below the shoulder formation 382, a recess 402 is formed in the outer surface 384 of the indexing mandrel 370. An o-ring 404 seals the interface between the outer surface 384 of the indexing mandrel 370 and the inner surface 392 of the ported seal housing 328 below the recess 402. Returning to FIG. 9, an indexing groove 400 is formed into the outer surface 384 of the indexing mandrel 370 between the o-ring 404 and a lower end 372 of the indexing mandrel 370. The indexing pin 346, coupled to the outer housing 310, is positioned within the indexing groove 400. The function of the indexing groove 400 and the indexing pin 346 is described in greater detail below.

The ball seat collet assembly 410 includes a collet member 412, a spring follower 414 and a spring 416. As will be described, the collet assembly 410 has limited axial mobility within the through bore 324 of the outer housing 310. The spring 416 is located within the through bore 356 defined by the spring housing 352. A shoulder formation 418 in the inner surface 420 of the spring housing 352 near the lower end 318 provides support to a lower end 422 of the spring 416. As can be seen more clearly in FIG. 10c, the spring follower 414 has a lower shoulder 424 that is seated atop an upper end 426 of the spring 416. The collet member 412 has a lower end 428 that is seated atop an upper shoulder 430 of the spring follower 414. From the collet member lower end 428, several cantilevered collet arms 432 extend upward. A collet head 434 is located at an upper end 436 of each collet arm 432. In the position shown in FIG. 9, each collet head 434 is biased outward by the corresponding cantilevered collet arm 432 to contact the inner surface 359 of the lower portion 354 of the swivel housing 334. The collet heads 434 form a collet through bore 438 having a collet inner radius 440.

When the bypass valve 300 is assembled, the spring 416 is lowered into the spring housing 352 and the spring follower 414 is placed atop the spring 416. The swivel housing 334 couples to the spring housing 352. However, the length of the spring 416 when loaded only with the spring follower 414 would extend beyond the lower end 360 of the lower portion 354 of the swivel housing 334 when the swivel housing 334 is coupled to the spring housing 352. Instead of loading the spring 416 with the swivel housing 334 while coupling to the spring housing 352, the spring sleeve 364 is coupled to the spring housing 352 to preload the spring 416, through the spring follower 414, against a lower shoulder 366. The smaller size of the spring sleeve 364 makes it easier to couple to the spring housing 352 while simultaneously preloading the spring 416. The larger swivel housing 334 may then be simply coupled to the spring housing 352. When disassembling the bypass valve 300, the spring sleeve 364 retains the spring 362 and spring follower 414 within the spring housing 352 while the swivel housing 334 is removed.

In an alternative embodiment a jetting housing (not shown) may be provided around the bypass valve 300. The jetting housing displaces annular space when the bypass valve 300 is to be used in a bore, such as that of a riser, having a sufficiently large inner diameter that annular fluid velocity would be lost if the bypass valve 300 were used alone. By reducing the annular area, fluid velocity through the ports 332 into the annulus 304 may be maintained at a rate that is effective for removing debris or circulating fluid.

When lowered downhole on the drill string, the bypass valve 300 is in a first position, as depicted in FIG. 9. In this position, the recess 402 of the indexing mandrel 370 is positioned inside the ports 332. As depicted in FIG. 10c, the outer seals 388, 390 of the bonded seal ring 380 are located above the ports 332 while the o-ring 404 is positioned below the ports 332 to prevent fluid communication between the through bore 376 and the annulus 304. Returning to FIG. 9, fluid may continue to flow through the through bore 376 defined by the spring loaded mandrel 368 and the through bore 356 defined by the spring housing 352. In the first position, the collet inner radius 440 is slightly smaller than the mandrel radius 378 (shown in FIGS. 10c and 10b, respectfully).

Referring to FIG. 11, when it is desired to actuate the bypass valve 300, a ball 450 is dropped through the drill string and circulated until it reaches the bypass valve 300. The ball 450 has a ball radius 452, which is less than the mandrel bore radius 378 and greater than the collet inner radius 440, thus permitting the ball 450 to continue to circulate through the bypass valve 300 until it comes to rest atop the collet heads 434 of the collet assembly 410. The ball 450 prevents further fluid flow through the bore 438, 456 of the collet assembly 410, spring 416, and spring housing 352. As the fluid pressure is increased, the collet assembly 410 is pushed downward against the upward force of the spring 416. The increased fluid pressure within the axial through bore 376 and the lower pressure outside of the mandrel 368 causes the spring loaded mandrel 368 to move downward as well. The indexing groove 400 on the indexing mandrel 370 interfaces with the indexing pin 346 to direct the position of the spring loaded mandrel 368 within the outer housing 310.

The indexing groove path 462 is depicted in FIG. 15. When the bypass valve 300 is in the first position, the indexing pin 346 is located in a first groove location 460. Referring to FIGS. 12 and 15, after the ball 450 is seated on the collet heads 434, fluid pressure is increased until the collet assembly 410 is driven downward against the force of the spring 416. The spring loaded mandrel 368 is also pushed downward by the increased fluid pressure within the axial bore 376. As the spring loaded mandrel 368 moves downward within the outer housing 310, the indexing pin 346 follows the indexing groove path 462 until it has reached a first groove wall 464. Upon contacting the first groove wall 464, the indexing pin 346 continues a path parallel to the first groove wall 464 until it has shouldered against second groove location 466. The outer housing 310 is rotationally fixed by the drill string. The spring loaded mandrel 368 is rotated within the outer housing 310 as the indexing pin 346 follows the indexing groove path 462. When the indexing pin 346 is shouldered against the second groove location 466, the bypass valve 300 is in a corresponding second position, shown in FIG. 12.

In the second position, the ball 450 remains seated atop the collet heads 434. The spring loaded mandrel 368 has moved a sufficient distance downward to open the ports 332, providing fluid communication from the through bore 324 to the annulus 304. So long as the fluid flow remains sufficient to provide pressure to the ball 450 and the collet assembly 410 to overcome the upward force of the spring 416, the bypass valve 300 will remain in the second position.

Referring to FIGS. 13 and 15, when the flow drops to below a predetermined flow rate corresponding to a predetermined fluid pressure, the spring 416 will push the collet assembly 410 upward. The collet assembly 410 in turn pushes the spring loaded mandrel 368 upward. The indexing pin 346 continues to follow the indexing groove path 462 and contacts a second groove wall 468. The indexing pin 346 follows the incline of the second groove wall 468 to rotate the spring loaded mandrel 368 within the outer housing 310 as it continues to move upward until the indexing pin 346 shoulders against a third groove location 470. When the indexing pin 346 is in the third groove location 470, the bypass valve 300 is in a corresponding third position, shown in FIG. 13.

In the third position, the ball 450 remains seated atop the collet heads 434. The ports 332 remain open, providing fluid communication from the through bore 324 to the annulus 304. In this position, the fluid can be reverse circulated at any desired rate. Circulation can be maintained up to a predetermined rate at which the fluid pressure would overcome the spring force once again. In the third position, multiple batches of various fluids can be circulated, depending upon the viscosity and density of the fluids, so long as the predetermined rate is not exceeded.

The fluid pressure may be increased to cycle the spring loaded mandrel 368 to the second position, in which the indexing pin 346 is shouldered against another second groove location 466. Decreasing the fluid pressure again will return the spring loaded mandrel 368 to the third position, wherein the indexing pin 346 is shouldered against another third groove location 470. This cycle may be continued until the indexing pin 346 has traversed the indexing groove path 462 to shoulder against a final third groove location 470, corresponding to the third position.

Referring to FIGS. 14 and 15, to close the bypass valve 300, the fluid pressure may be increased when the indexing pin 346 is shouldered against the final third groove location 470. As previously described, as the fluid pressure is increased, the collet assembly 410 and mandrel 368 are driven downward against the force of the spring 416. This time, however, the indexing pin 346 is directed along the indexing groove path 462 until it shoulders against a final groove location 472. The final groove location 472 corresponds to a fourth position of the spring loaded mandrel 368 that is farther downhole, relative to the outer housing 310, than in the first, second, or third positions. In the fourth position, the collet assembly 410 is driven downward against the force of the spring 416 until the collet heads 434 are received into corresponding recess formations 358 in the lower portion 354 of the swivel housing 334. Once the collet heads 434 spring outward into the recess formations 358, the collet inner radius 440 is enlarged such that it is larger than the ball radius 452. The ball 450 is then forced downward through the bore 438 of the collet assembly 310 and the bore 356 of the spring housing 352. The ball 450 will be caught in a downstream ball catcher (not shown). When the ball 450 is released from the collet heads 434, the fluid pressure counteracting the spring force is relieved and the spring 416 pushes the collet assembly 410 upward. The collet assembly 410 in turn pushes the spring loaded mandrel 368 upward. The indexing groove 400 and pin 346 interact to reposition the spring-loaded mandrel 368 in the first position in which the ports 332 are closed and from which the entire process may be performed again.

While the claimed subject matter has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the claimed subject matter as disclosed herein. Accordingly, the scope of the claimed subject matter should be limited only by the attached claims.

Claims

1. An apparatus for cleaning a wellbore casing comprising: an outer housing having an axial through passage between an inlet and a first outlet wherein the inlet and the first outlet are adapted for connection in a work string, the outer housing having a second outlet extending in a direction generally transversely of the through passage; an index mandrel slidably located within the outer housing and having an axial bore extending therethrough, the index mandrel being movable relative to the outer housing between a first position in which the second outlet is closed and a second position in which the second outlet is open; a ball seat located on an upper end of the index mandrel; a spring located within the outer housing and biasing the index mandrel toward the first position; a ball retainable on the ball seat to prevent flow from the inlet to the first outlet; and wherein application of a first pressure on the ball forces the index mandrel against the spring into the second position and reduction of said first pressure permits return of the index mandrel to the second position.

2. The apparatus of claim 1, further comprising: an indexing pin retained on an inner surface of the outer housing; wherein the index mandrel has an indexing groove in an outer surface; and wherein the indexing pin cooperates with the indexing groove to position the index mandrel in the first position and the second position.

3. The apparatus of claim 2, wherein the index mandrel has a third position, between the first position and the second position, in which the second outlet is closed.

4. The apparatus of claim 1, further comprising: a jet housing around the outer housing, the jet housing including a plurality of nozzles in fluid communication with the second outlet and positioned to direct fluid received from the second outlet in a direction substantially perpendicular to the axial through passage.

5. The apparatus of claim 4, wherein the jet housing further comprises: a plurality of nozzles in fluid communication with the second outlet and positioned to direct fluid received from the second outlet in a direction substantially tangent to the jet housing.

6. The apparatus of claim 5, wherein the jet housing is rotatable about the outer housing.

7. The apparatus of claim 1, wherein the ball is deformable to be pushed through the ball seat and discharged through the first outlet.

8. The apparatus of claim 1, further comprising: a ball catcher sub positioned below the outer housing, the ball catcher sub comprising: a ball catcher housing having a ball catcher axial through passage between a ball catcher inlet and a ball catcher outlet wherein the ball catcher inlet and the ball catcher outlet are adapted for connection in a work string; a trap finger pivotally retained within the ball catcher housing, wherein the trap finger is pivotable to receive the ball when discharged from the first outlet; a ball catcher tube retained within the ball housing and having a length and an inner diameter sufficient to hold a plurality of balls; and wherein an annulus is formed between the ball catcher tube and the ball catcher housing sufficient for fluid to be communicated through the ball catcher sub.

9. The apparatus of claim 8, wherein the trap finger pivots downward to receive the ball within the ball catcher tube and cannot pivot upwards, thereby preventing the ball from escaping the ball catcher tube when fluid is reverse circulated through the axial through passage.

10. The apparatus of claim 8, wherein the ball catcher tube has a plurality of holes therein to communicate fluid from the ball catcher tube to the annulus.

11. A method of cleaning an inner surface of a casing in a wellbore comprising: lowering a jetting tool on a work string into the wellbore to a desired location, wherein the jetting tool has an outer housing with an axial through passage between an inlet and a first outlet, the outer housing also having a second outlet substantially transverse to the axial through passage, and an index housing slidingly retained within the outer housing in a first position such that the second outlet is closed, the index housing having a ball seat on an upper end and being biased toward the first position; dropping a ball into the axial through passage to rest on the ball seat, thereby preventing fluid flow between the inlet and the first outlet of the axial through passage, causing fluid pressure to force the index housing to a second position wherein the second outlet is open; circulating fluid from the axial through passage and the second outlet at a fluid pressure sufficient to clean the casing; decreasing the fluid pressure to return the index housing to the first position; increasing the fluid pressure to move the index housing to a third position wherein the second outlet is closed; and wherein the increased fluid pressure is sufficient to shear the ball from the ball seat, thereby reducing the fluid pressure on the index housing causing it to return to the first position.

12. The method of claim 11, further comprising: rotating the jetting tool while circulating the fluid to direct the circulating fluid circumferentially around the inner surface of the casing.

13. The method of claim 12, further comprising: raising and lowering the jetting tool in the wellbore while circulating the fluid to clean a longitudinal area of the inner surface of the casing.

14. The method of claim 13, further comprising: positioning the jetting tool within the blowout preventor; and circulating the fluid from the axial through passage and the second outlet at a fluid pressure sufficient to clean the blowout preventor.

15. The method of claim 11, further comprising: catching the ball in a ball catcher located below the index housing.

16. The method of claim 15, further comprising: reverse circulating the fluid through the axial through passage; and retaining the ball in the ball catcher with a trap finger during reverse circulation.

17. A method of opening and closing an outlet through a side of a cylindrical outer housing of a jetting tool in a wellbore, the method comprising: biasing the index housing to an upward position within the outer housing in which the index housing is blocking the fluid outlet through the side of the outer housing; dropping a ball to seal against a ball seat located at the upper end of the index housing and block fluid flow through the jetting tool; forcing the index housing to a lower position inside the outer housing as a result of increased pressure behind the ball, wherein the fluid outlet through the side of the outer housing is open; reducing the fluid pressure on the ball to permit the biasing of the index housing towards the upward position, wherein the fluid outlet through the side of the outer housing is closed; and increasing the fluid pressure on the ball to a pressure sufficient to shear the ball through the ball seat, thereby permitting the index housing to return to the upward position.

18. The method of claim 17, wherein the fluid pressure is increased and decreased a quantity of times to open and close the fluid outlet through the side of the outer housing before increasing the fluid pressure sufficient to shear the ball.

19. The method of claim 18, further comprising: dropping a second ball after shearing the first ball to seal against the ball seat and block fluid flow through the jetting tool; repeating the forcing, repeating, and increasing steps.