CA1177058A - Jar tool - Google Patents
Jar toolInfo
- Publication number
- CA1177058A CA1177058A CA000393583A CA393583A CA1177058A CA 1177058 A CA1177058 A CA 1177058A CA 000393583 A CA000393583 A CA 000393583A CA 393583 A CA393583 A CA 393583A CA 1177058 A CA1177058 A CA 1177058A
- Authority
- CA
- Canada
- Prior art keywords
- section
- mandrell
- housing
- piston assembly
- tool
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012530 fluid Substances 0.000 claims abstract description 42
- 238000012856 packing Methods 0.000 claims description 14
- 230000008878 coupling Effects 0.000 claims description 8
- 238000010168 coupling process Methods 0.000 claims description 8
- 238000005859 coupling reaction Methods 0.000 claims description 8
- 238000007789 sealing Methods 0.000 claims description 8
- 238000005553 drilling Methods 0.000 claims description 6
- 230000035939 shock Effects 0.000 claims description 5
- 230000006835 compression Effects 0.000 abstract 1
- 238000007906 compression Methods 0.000 abstract 1
- 210000004907 gland Anatomy 0.000 description 14
- 230000000295 complement effect Effects 0.000 description 6
- 239000010720 hydraulic oil Substances 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B31/00—Fishing for or freeing objects in boreholes or wells
- E21B31/107—Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars
- E21B31/113—Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically-operated
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Marine Sciences & Fisheries (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
Abstract
ABSTRACT A jar tool for use in a drill string for use in dislodging a drill bit or well-tools trapped in well bores. The tool comprises an outer housing adapted to move longitudinally with respect to an inner spline mandrell. A piston assembly is acted on by a piston actuator and hydraulic fluid restricts the movement of the piston assembly and, therefore, the movement of the mandrell relative to the housing, while the piston assembly is within a narrower portion of a hydraulic cylinder. When the piston assembly reaches a larger diameter portion of the cylinder, the hydraulic fluid rushes past the piston assembly which allows a knocker connected to the spline mandrell to collide with the outer housing. A compression spring returns the piston assembly to its rest position abutting a shoulder on the outer housing. Provision is made for a valve to be inserted in the piston assembly so that the system can be temperature compensated and more desirable hydraulic fluids can be used.
Description
~1'7~7~51~
FIELD OF THE INVENTION
This invention relates to improvements made in jar tools used ~or well drilling.
BACKGROUND OF_ THE INVENTION
Jar tools are extensively used in the oil drilling industry to dislodge drill bits, drill string sections, or other well tools trapped in well bores. An example of such a jar tool is disclosed in U,S. Patent 3,716,109 (Griffiths) entitled ROTARY
JAR and owned by the applicantO U.S. Patent 3,716,109 discloses a jar tool which has been in satisfactory use for a number of years.
Problems have remained with the paten~ed appara~us, however, which have resulted in improvements being made which are the subject o this application.
U.S. Patent 3,716,109 discloses a jar tool having a spline mandrell and an outer housing, t.he mandrell and the housing being able to move longitudinally relative to each other. A
knocker is connected to ~he mandrell and it collides with an anvil which is connected to the housing. The collision or ~k (35~
impact between them causes the jar on the drill string and it sh~uld be appreciated that the impact is violent and the operating conditions under which the tool iS used are extreme~
This impact is created by the sudden release of entrapped hydraulic fluid which is allowed to rush by a piston assembly travelling from a relatively narrow diameter of a hydraulic cylinder into a relatively larger diameter where the fluid flow past the piston is largely unimpeded.
To actuate the piston assembly, a piston actuator is used.
This piston actuator includes resilient fingers extending from the actuator and towards the piston. The fingers engage a resilient part on the piston assembly when contact is made and provide a "pulling" action on the piston assembly to return it to its home position following the jar. The technique of using these fingers and the necessary costs entailed in using them and complementary parts on the piston assembly is expensive and complicated.
Further, it was considered desirable to improve the metering system~ The use of the metering system, required fluids that, although having viscosity characteristics more constant under different operating temperatures, did not have desirable lubricating qualities. The metering system could be improved by selecting tempera~ure compensable valves within the '70~8 metering system and pressure relief valves. The metering and pressure relief ~alves may be used in various combinations to achieve desirable operating characteristics.
The use of a metering system which allows for the changes in fluid viscosity and density as the temperatures within the drill hole vary, allows for the use of more desirable fluids from a lubriction view point.
SUMMARY OF THE INVENTION
Accordingly, the invention disclosed and claimed is a jar tool for use in a drill string, said jar tool comprising:
A jar tool for use in a drill string, said jar tool comprising:
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section ~ 3'7~8 being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions~
respective pairs of abutment faces between said housing and said mandrell to deEine said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting ko seal said third section from said first section, said third section being located adjacen~ said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston s~
assembly, said piston assembly further defining a metering passageway for hydraulic ~luid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position, BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying t7~7~
drawings in which:
Figure 1 is a cross-sectional view of the jar tool in its entirety;
Figure 2 iæ a cros -sectional view of the pis~on of the jar tool in position just prior to the jar being initiated;
Figure 3 is a cross-section view of the piston of the jar tool in a fully open position;
Figure 4 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and metering valves in a parallel configuration;
Figure 5 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and pressure valves in a combination parallel and series con~iguration;
Figure 6 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and pressure valves in a series configuration; and Figure 7 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing only a pressure relief valve configuration.
~:~'7'~()~ !3 -- 7 ~
DESCRIP'rION OF A SPECIFIC EMBODIMENT
_ __ _ Referring now to Figure 1, a jar tool is shown generally at 10. The jar tool 10 comprises a spline mandrell 11 and an outer housing 12.
Spline mandrell 11 is made up of a threaded socket 13 adapted to receive an adjacent piece of drill pipe (not shown) within the head portion 14 of the mandrell 11.
Hexagonal splines 15 extend longitudinally along mandrell 11 to threaded portion 16. A knocker 17 is connected through complementary threads at 16. Impact ring 18 is mounted between knscker 17 and shoulder 79 on spline mandrell 11. Knocker 17 has an opposed threaded end 19 and a piston mandrell 20 is threadedly connected to knocker 17 by way of thr~aded connection 19. Xnocker 17 also includes two O-rings 27, which act as a seal between knocker 17, spline mandrell 11 and piston mandrell 20.
Mounted on an opposed threaded connection 21 of piston mandrell 20 is a washpipe 22 which extends longitudinally alon~
the axis of jar tool 10 and terminates at end 23.
A piston actuator 24 (see also Figure 2) is threadedly connected to complementary threads 25 on washpipe 22. An ,, ~ . .. . . .
L77~
O-ring 26 acts as a seal between piston mandrell 20 and washpipe 22.
~ he outer housing 12 comprises several sections. A sealing housing 29 extends from head portion 14 of spline mandrell 11 to a threaded onnection 30. The sealing housing 29 has polypak 80 ac~ing as a seal between sealing housing 29 and head portion 14 of spline mandrell 11. Sealing housing 29 also includes bearing bushing 81 and cylinder fill plug 82 for adding hydraulic fluid to the jar tool 10. A spline housing 31 has complementary threads at 30 and, additionally, further threads 32 which are located at its opposed end. A knocker housing 33 is mounted on threads 32 and extends longitudinally from spline housing 31 to female threaded connection 34.
0-rings 83 act between spline housing 31, sealing housing 29 and knocker housing 33, respectively, A cylinder fill plug 35 acts as a port for adding hydraulic fluid to the jar tool 10 in the upper chamber 55.
A packing sub 36 with complementary threaded connection 34 is connected to knocker housing 33 and it has an opposed threaded connection 37 which allows complementary threads of hydraulic cylinder 38 to be mounted thereon. Two O-rings 39 act as seals between the packing sub 36~ knocker housing 33 and hydraulic cylinder 38, respectively.
3t7~
_ g _ Packing sub 36 has an internally formed shoulder 41 and an inner diameter which changes from a ~aximum area at 42 to a minimum area 43. Packing sub 36 also includes a further threaded connection 44.
Hydraulic cylinder 38 extends from the packing sub 36 to a threaded connection 45 and includes two cylinder fill plugs 35 in its periphery. The inside of hydraulic cylinder 38 is formed into three main diameters 46, 47 and 48 with a transition portion 49 existing between diameters 46 and 47~ A
shoulder 50 is formed between diameters 47 and 48.
Washpipe housing 51 is connected to hydraulic cylinder 38 at threaded ~onnection 45 and extends longitudinally to threaded connection 52. An O-ring ~3 acts as a seal between hydraulic cylinder 38 and washpipe housing 51.
The various apparatus which are located between the several sections of the outer housing 12 and spline mandrell 11, respectively, will now be described.
A knocker gland 54 is mounted between the knocker 17 and packing sub 36 in upper chamber 55. Knocker gland 54 contains four polypak rings 56 which act as seals between the knocker gland 54, knocker housing 33 and piston mandrell 20, respectively.
s~
-- 10 ~
Seated against shoulder 57 o~ packing sub 36 is O-ring gland 58. O~ring gland 58 includes four O~rings and back up rings 59 which act between the packing sub 36 and piston mandrell 20. A female junk ring 60 abuts O-ring gland 58 and V-rings 61 are inserted between female junk ring 60 and male junk ring 62. A packing spring 63 is inser~ed between male junk ring 62 and upper gland nut 64. Upper gland nut 64 is threadedly connected ~o packing sub 36 at threaded connection 44 and includes a wiper ring 65 acting between piston mandrell 20 and upper gland nut 64.
On shoulder 41 of packing sub 36 in the area 43 between the packing sub 36 and piston mandrell 20, a second female junk ring 85 is positioned together with V-rings 66 and male junk ring 67. One end of piston return spring 68 abuts male junk ring 67 and the other is in contact with piston assembly 69.
Piston assembly 69 abuts shoulder 50 in hydraulic cylinder 38 in its rest position and is shown more clearly in Figures 2 and 3. There is a close tolerance between the piston assembly 69 and the diameter of the piston mandrell 20 and hydraulic cylinder 380 The piston assembly 69 includes a piston cup 70.
The metering valve 86 is removable from the piston assembly 69 and may be replaced with other suitable valves depending on the operating conditions. Metering valves manufactured by the Lee ~ 7'~0$~3 Company, Arlington, Texas, are particularly appropriate for this type of application.
A filter cage 71 (Figure 2) is also installed within the piston assembly 69 to remove contaminants within the hydraulic oil prior to passing through the metering and/or valve system Piston return spring 68 retains piston assembly 69 against shoulder 50 and also acts to retain the V-rings 66, male junk ring 67 and female junk ring 85 (Figure 1) in the positions depicted.
An O-ring gland 72 is inserted between washpipe housing 51 and washpipe 22. The O-ring gland 72 contains four O-rings and back up rings 73 which act as seals between the O-ring gland 72, washpipe housing 51 and washpipe 22, respectively. A gland nut 74 is connected to washpipe housing 51 at threaded connection 75 and a retaining ring 76 retains the gland nut 74 in position.
Referring now to Figure 4, an enlarged view o~ the piston assembly 69 i5 shown in which an alternative embodiment of the invention is described. In this embodiment, the piston assembly 69 is provided with a metering valve 86 as well as a pressure relief valve 85 which is inserted in the piston assembly 69 in a configuration parallel to that of the metering valve 86.
5~3 Referring now to Figure 5, an ~nlarged view o the piston assembly 69 is shown in which a further embodiment of the inven~ion is described. In this embodiment, the piston assembly Ç9 is provided with a metering valve 86 and a pressure relief valve 95 in serles on one side of the piston assembly 69 and with a pressure relief valve 95 only on the opposite side.
Referring now to Figure 6, an enlarged view of the piston assembly 69 is shown in which a further embodiment of the invention is described. In this embodiment, the piston assembly 69 is provided with a pressure relief valve 95 and a metering valve 86.
Referring now to Figure 7, an enlarged view of the piston assembly 69 is shown in which yet a further embodiment of the invention is described~ In this embodiment, the piston assembly 69 is provided with a pressure relief valve 95 only.
OPERATION
In operation, when the driller wishes to operate the jar tool, it will be assumed the tool is originally in the position shown in Figure 1. The driller com~ences to apply a tension which tends to lift the drill string in the direction indicated 11 7; 1) S t3 by ~he arrow and, in so doing, force will be applied between the spline mandrell 11 and the outer housing 12. The head portion 14 of the spline mandrell 11 therefore, will begin to move away from sealing housing 29 at their abutting faces 87 such that cylindrical surface B5 is expose~. As spline mandrell 11 moves relative to outer housing 12~ piston actuator 24 will also move leftwardly with piston mandrell 20. When piston actuator 24 contacts piston assembly 69, piston assembly 69 will move away from shoulder 50 under the influence of the piston actuator 24 as seen in Figure 2 since the counter-acting force against piston assembly 69 by piston return spring 68 is relatively much smaller than the force from the piston actuator 24. Hydraulic cylinder 38, however, contains hydraulic fluid 77 and the oil cannot pass from area 47 of hydraulic cylinder 38 to area 48 without passing through metering valve 86.
Accordingly, the relatively slow passage of hydraulic fluid 77 through metering valve 86 restricts the speed at which the spline mandrell 11 and outer housing 12 can move relative to each other until the piston assembly 69 reaches the position shown in Figure 2. This builds up pressure within the area 46 which causes a large tensile force buildup between the two ends of the tool lO.
When the piston assembly 69, including piston cup 70 however, passes into area 46 under the continued influence of '7()5~
piston actuator 24, hydraulic oil 77 is free to pass around the piston assembly 69 and into areas 47 and 48 wi~h the result that the spline mandrell ll and outer housing 12 increase their movement relative to each other enormously. ThuS, impact ring 18 on knocker 17 collides violently with impact surface 78 of spline housing 31 and this collision causes a jar or shock to the drill string. The tool assumes the condi~ion depicted in Figure 3.
The driller will ordinarily jar the ~ool several times to free the stuck drill bit or well tool and, therefore, he will now ordinarily lower the drill pipe. Piston assembly 69, under the influence of piston return spring 68, will closely follow piston actuator 24 until it returns to its rest position against shoulder 50 of hydraulic cylinder 38. Thereafter, the piston actuator may return to its rest position as depicted in Figure l before a further jar is initiated by the driller.
There are many further modifications which can be made to the specific embodiment of the invention just described which changes, however, may still fall within the scope and spirit of the invention.
FIELD OF THE INVENTION
This invention relates to improvements made in jar tools used ~or well drilling.
BACKGROUND OF_ THE INVENTION
Jar tools are extensively used in the oil drilling industry to dislodge drill bits, drill string sections, or other well tools trapped in well bores. An example of such a jar tool is disclosed in U,S. Patent 3,716,109 (Griffiths) entitled ROTARY
JAR and owned by the applicantO U.S. Patent 3,716,109 discloses a jar tool which has been in satisfactory use for a number of years.
Problems have remained with the paten~ed appara~us, however, which have resulted in improvements being made which are the subject o this application.
U.S. Patent 3,716,109 discloses a jar tool having a spline mandrell and an outer housing, t.he mandrell and the housing being able to move longitudinally relative to each other. A
knocker is connected to ~he mandrell and it collides with an anvil which is connected to the housing. The collision or ~k (35~
impact between them causes the jar on the drill string and it sh~uld be appreciated that the impact is violent and the operating conditions under which the tool iS used are extreme~
This impact is created by the sudden release of entrapped hydraulic fluid which is allowed to rush by a piston assembly travelling from a relatively narrow diameter of a hydraulic cylinder into a relatively larger diameter where the fluid flow past the piston is largely unimpeded.
To actuate the piston assembly, a piston actuator is used.
This piston actuator includes resilient fingers extending from the actuator and towards the piston. The fingers engage a resilient part on the piston assembly when contact is made and provide a "pulling" action on the piston assembly to return it to its home position following the jar. The technique of using these fingers and the necessary costs entailed in using them and complementary parts on the piston assembly is expensive and complicated.
Further, it was considered desirable to improve the metering system~ The use of the metering system, required fluids that, although having viscosity characteristics more constant under different operating temperatures, did not have desirable lubricating qualities. The metering system could be improved by selecting tempera~ure compensable valves within the '70~8 metering system and pressure relief valves. The metering and pressure relief ~alves may be used in various combinations to achieve desirable operating characteristics.
The use of a metering system which allows for the changes in fluid viscosity and density as the temperatures within the drill hole vary, allows for the use of more desirable fluids from a lubriction view point.
SUMMARY OF THE INVENTION
Accordingly, the invention disclosed and claimed is a jar tool for use in a drill string, said jar tool comprising:
A jar tool for use in a drill string, said jar tool comprising:
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section ~ 3'7~8 being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions~
respective pairs of abutment faces between said housing and said mandrell to deEine said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting ko seal said third section from said first section, said third section being located adjacen~ said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston s~
assembly, said piston assembly further defining a metering passageway for hydraulic ~luid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position, BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying t7~7~
drawings in which:
Figure 1 is a cross-sectional view of the jar tool in its entirety;
Figure 2 iæ a cros -sectional view of the pis~on of the jar tool in position just prior to the jar being initiated;
Figure 3 is a cross-section view of the piston of the jar tool in a fully open position;
Figure 4 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and metering valves in a parallel configuration;
Figure 5 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and pressure valves in a combination parallel and series con~iguration;
Figure 6 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing the relief and pressure valves in a series configuration; and Figure 7 is an enlarged cross-sectional view of the area IV-IV of Figure 1 showing only a pressure relief valve configuration.
~:~'7'~()~ !3 -- 7 ~
DESCRIP'rION OF A SPECIFIC EMBODIMENT
_ __ _ Referring now to Figure 1, a jar tool is shown generally at 10. The jar tool 10 comprises a spline mandrell 11 and an outer housing 12.
Spline mandrell 11 is made up of a threaded socket 13 adapted to receive an adjacent piece of drill pipe (not shown) within the head portion 14 of the mandrell 11.
Hexagonal splines 15 extend longitudinally along mandrell 11 to threaded portion 16. A knocker 17 is connected through complementary threads at 16. Impact ring 18 is mounted between knscker 17 and shoulder 79 on spline mandrell 11. Knocker 17 has an opposed threaded end 19 and a piston mandrell 20 is threadedly connected to knocker 17 by way of thr~aded connection 19. Xnocker 17 also includes two O-rings 27, which act as a seal between knocker 17, spline mandrell 11 and piston mandrell 20.
Mounted on an opposed threaded connection 21 of piston mandrell 20 is a washpipe 22 which extends longitudinally alon~
the axis of jar tool 10 and terminates at end 23.
A piston actuator 24 (see also Figure 2) is threadedly connected to complementary threads 25 on washpipe 22. An ,, ~ . .. . . .
L77~
O-ring 26 acts as a seal between piston mandrell 20 and washpipe 22.
~ he outer housing 12 comprises several sections. A sealing housing 29 extends from head portion 14 of spline mandrell 11 to a threaded onnection 30. The sealing housing 29 has polypak 80 ac~ing as a seal between sealing housing 29 and head portion 14 of spline mandrell 11. Sealing housing 29 also includes bearing bushing 81 and cylinder fill plug 82 for adding hydraulic fluid to the jar tool 10. A spline housing 31 has complementary threads at 30 and, additionally, further threads 32 which are located at its opposed end. A knocker housing 33 is mounted on threads 32 and extends longitudinally from spline housing 31 to female threaded connection 34.
0-rings 83 act between spline housing 31, sealing housing 29 and knocker housing 33, respectively, A cylinder fill plug 35 acts as a port for adding hydraulic fluid to the jar tool 10 in the upper chamber 55.
A packing sub 36 with complementary threaded connection 34 is connected to knocker housing 33 and it has an opposed threaded connection 37 which allows complementary threads of hydraulic cylinder 38 to be mounted thereon. Two O-rings 39 act as seals between the packing sub 36~ knocker housing 33 and hydraulic cylinder 38, respectively.
3t7~
_ g _ Packing sub 36 has an internally formed shoulder 41 and an inner diameter which changes from a ~aximum area at 42 to a minimum area 43. Packing sub 36 also includes a further threaded connection 44.
Hydraulic cylinder 38 extends from the packing sub 36 to a threaded connection 45 and includes two cylinder fill plugs 35 in its periphery. The inside of hydraulic cylinder 38 is formed into three main diameters 46, 47 and 48 with a transition portion 49 existing between diameters 46 and 47~ A
shoulder 50 is formed between diameters 47 and 48.
Washpipe housing 51 is connected to hydraulic cylinder 38 at threaded ~onnection 45 and extends longitudinally to threaded connection 52. An O-ring ~3 acts as a seal between hydraulic cylinder 38 and washpipe housing 51.
The various apparatus which are located between the several sections of the outer housing 12 and spline mandrell 11, respectively, will now be described.
A knocker gland 54 is mounted between the knocker 17 and packing sub 36 in upper chamber 55. Knocker gland 54 contains four polypak rings 56 which act as seals between the knocker gland 54, knocker housing 33 and piston mandrell 20, respectively.
s~
-- 10 ~
Seated against shoulder 57 o~ packing sub 36 is O-ring gland 58. O~ring gland 58 includes four O~rings and back up rings 59 which act between the packing sub 36 and piston mandrell 20. A female junk ring 60 abuts O-ring gland 58 and V-rings 61 are inserted between female junk ring 60 and male junk ring 62. A packing spring 63 is inser~ed between male junk ring 62 and upper gland nut 64. Upper gland nut 64 is threadedly connected ~o packing sub 36 at threaded connection 44 and includes a wiper ring 65 acting between piston mandrell 20 and upper gland nut 64.
On shoulder 41 of packing sub 36 in the area 43 between the packing sub 36 and piston mandrell 20, a second female junk ring 85 is positioned together with V-rings 66 and male junk ring 67. One end of piston return spring 68 abuts male junk ring 67 and the other is in contact with piston assembly 69.
Piston assembly 69 abuts shoulder 50 in hydraulic cylinder 38 in its rest position and is shown more clearly in Figures 2 and 3. There is a close tolerance between the piston assembly 69 and the diameter of the piston mandrell 20 and hydraulic cylinder 380 The piston assembly 69 includes a piston cup 70.
The metering valve 86 is removable from the piston assembly 69 and may be replaced with other suitable valves depending on the operating conditions. Metering valves manufactured by the Lee ~ 7'~0$~3 Company, Arlington, Texas, are particularly appropriate for this type of application.
A filter cage 71 (Figure 2) is also installed within the piston assembly 69 to remove contaminants within the hydraulic oil prior to passing through the metering and/or valve system Piston return spring 68 retains piston assembly 69 against shoulder 50 and also acts to retain the V-rings 66, male junk ring 67 and female junk ring 85 (Figure 1) in the positions depicted.
An O-ring gland 72 is inserted between washpipe housing 51 and washpipe 22. The O-ring gland 72 contains four O-rings and back up rings 73 which act as seals between the O-ring gland 72, washpipe housing 51 and washpipe 22, respectively. A gland nut 74 is connected to washpipe housing 51 at threaded connection 75 and a retaining ring 76 retains the gland nut 74 in position.
Referring now to Figure 4, an enlarged view o~ the piston assembly 69 i5 shown in which an alternative embodiment of the invention is described. In this embodiment, the piston assembly 69 is provided with a metering valve 86 as well as a pressure relief valve 85 which is inserted in the piston assembly 69 in a configuration parallel to that of the metering valve 86.
5~3 Referring now to Figure 5, an ~nlarged view o the piston assembly 69 is shown in which a further embodiment of the inven~ion is described. In this embodiment, the piston assembly Ç9 is provided with a metering valve 86 and a pressure relief valve 95 in serles on one side of the piston assembly 69 and with a pressure relief valve 95 only on the opposite side.
Referring now to Figure 6, an enlarged view of the piston assembly 69 is shown in which a further embodiment of the invention is described. In this embodiment, the piston assembly 69 is provided with a pressure relief valve 95 and a metering valve 86.
Referring now to Figure 7, an enlarged view of the piston assembly 69 is shown in which yet a further embodiment of the invention is described~ In this embodiment, the piston assembly 69 is provided with a pressure relief valve 95 only.
OPERATION
In operation, when the driller wishes to operate the jar tool, it will be assumed the tool is originally in the position shown in Figure 1. The driller com~ences to apply a tension which tends to lift the drill string in the direction indicated 11 7; 1) S t3 by ~he arrow and, in so doing, force will be applied between the spline mandrell 11 and the outer housing 12. The head portion 14 of the spline mandrell 11 therefore, will begin to move away from sealing housing 29 at their abutting faces 87 such that cylindrical surface B5 is expose~. As spline mandrell 11 moves relative to outer housing 12~ piston actuator 24 will also move leftwardly with piston mandrell 20. When piston actuator 24 contacts piston assembly 69, piston assembly 69 will move away from shoulder 50 under the influence of the piston actuator 24 as seen in Figure 2 since the counter-acting force against piston assembly 69 by piston return spring 68 is relatively much smaller than the force from the piston actuator 24. Hydraulic cylinder 38, however, contains hydraulic fluid 77 and the oil cannot pass from area 47 of hydraulic cylinder 38 to area 48 without passing through metering valve 86.
Accordingly, the relatively slow passage of hydraulic fluid 77 through metering valve 86 restricts the speed at which the spline mandrell 11 and outer housing 12 can move relative to each other until the piston assembly 69 reaches the position shown in Figure 2. This builds up pressure within the area 46 which causes a large tensile force buildup between the two ends of the tool lO.
When the piston assembly 69, including piston cup 70 however, passes into area 46 under the continued influence of '7()5~
piston actuator 24, hydraulic oil 77 is free to pass around the piston assembly 69 and into areas 47 and 48 wi~h the result that the spline mandrell ll and outer housing 12 increase their movement relative to each other enormously. ThuS, impact ring 18 on knocker 17 collides violently with impact surface 78 of spline housing 31 and this collision causes a jar or shock to the drill string. The tool assumes the condi~ion depicted in Figure 3.
The driller will ordinarily jar the ~ool several times to free the stuck drill bit or well tool and, therefore, he will now ordinarily lower the drill pipe. Piston assembly 69, under the influence of piston return spring 68, will closely follow piston actuator 24 until it returns to its rest position against shoulder 50 of hydraulic cylinder 38. Thereafter, the piston actuator may return to its rest position as depicted in Figure l before a further jar is initiated by the driller.
There are many further modifications which can be made to the specific embodiment of the invention just described which changes, however, may still fall within the scope and spirit of the invention.
Claims (18)
PRIVILEGE OR PROPERTY IS CLAIMED IS DEFINED AS FOLLOWS:
1. A jar tool for use in a drill string, said jar tool comprising:
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position.
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position.
2. A jar tool as in claim 1 wherein said metering passageway includes a metering valve which allows only a small portion of hydraulic fluid to flow through said piston assembly when there exists contact between said piston assembly and said piston actuator.
3. A jar tool as in claim 2 wherein said metering valve is temperature compensable whereby fluid flowing through said metering valve flows at a relatively constant rate independent of the viscosity of said hydraulic fluid.
4. A jar tool as in claim 2 wherein said metering passageway further includes a pressure relief valve which allows no fluid to pass therethrough until a predetermined pressure in said hydraulic fluid is reached.
5. A jar tool as in claim 2 wherein a further passageway is provided through said piston assembly, said further passageway including a pressure relief valve, said pressure relief valve allowing passage of said hydraulic fluid through said piston assembly where a predetermined pressure on said hydraulic fluid is reached.
6. A jar tool as in claim 4 wherein a further passageway is provided through said piston assembly, said further passageway including a second pressure relief valve whereby said second pressure relief valve does not open until a predetermined pressure is reached.
7. A jar tool as in claim 1 wherein said metering passageway includes a pressure relief valve, said relief valve allowing no fluid to pass through said passageway until a predetermined pressure is reached.
8. A jar tool as in claim 1 wherein said housing comprises a plurality of sections, each of said sections being connected to and detachable from adjacent sections.
9. A jar tool as in claim 8 wherein said mandrell comprises a plurality of connected sections, each of said sections being connected to and detachable from adjacent sections, said mandrell extending from one end of said housing to the other.
10. A jar tool as in claim 9 wherein said plurality of sections comprising said mandrell includes a spline mandrell having a female threaded connection for connection to an adjacent piece of drill pipe, splines connected to said spline mandrell, a male threaded connection extending from the end of said spline mandrell opposed to the end containing said female threaded connection, a knocker connected to said male threaded connection, a piston mandrell connected to said knocker at one end and a washpipe connected to said knocker at said opposite end.
11. A jar tool as in claim 10 wherein said plurality of sections comprising said housing includes a sealing housing, a spline housing connected to said sealing housing at one end, a knocker housing connected to said spline housing at the opposite end, a packing sub connected to said knocker housing at one end, a hydraulic cylinder connected to said packing sub at the opposite end and a washpipe housing connected to the opposite end of said hydraulic cylinder from said knocker.
12. A jar tool as in claim 11 wherein said washpipe housing includes a male threaded connection for attachment to an adjacent piece of drill pipe.
13. A jar tool as in claim 12 and further comprising an impact ring mounted on said knocker and acting to contact said abutment face on said housing, said abutment face being located on said spline housing.
14. A jar tool for use in a drill string, said jar tool comprising:
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit tongue between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section wherein said fluid flows through said metering passageway to said second section wherein said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position.
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit tongue between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section wherein said fluid flows through said metering passageway to said second section wherein said fluid freely flows past said piston allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string; and wherein said spring means acts to return said piston assembly to said shoulder position when said tool moves from said open to said closed position.
15. A jar tool for use in a drill string, said jar tool comprising:
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
a metering valve and a pressure relief valve in said metering passageway whereby said hydraulic fluid will flow through said metering passageway until a predetermined pressure is reached;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston assembly allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string.
a mandrell adapted to be connected at one end to an adjacent piece of drill pipe;
a housing surrounding the major portion of said mandrell and defining therein a passageway for drilling fluid and an annular chamber for hydraulic fluid, said annular chamber having first, second and third sections, said first section being of relatively smaller diameter and located adjacent to said second section and said third section being located adjacent said first section;
coupling means between said mandrell and said housing, said coupling means acting to transmit torque between said mandrell and said housing and to allow longitudinal relative movement between said housing and said mandrell between closed and open positions;
respective pairs of abutment faces between said housing and said mandrell to define said closed and open positions of said tool;
a piston assembly mounted within said annular chamber and around said mandrell, said assembly being adapted to move longitudinally relative to said housing and mandrell between said first section and said second section and acting to seal said third section from said first section, said third section being located adjacent said first section on the end of said piston assembly opposed from said second section, said first section being adapted to closely receive said piston assembly;
shoulder means in said annular chamber between said first and third sections defining a rest position for said piston assembly, said piston assembly further defining a metering passageway for hydraulic fluid;
a metering valve and a pressure relief valve in said metering passageway whereby said hydraulic fluid will flow through said metering passageway until a predetermined pressure is reached;
piston actuation means mounted on said mandrell in said third section and acting to actuate and move said piston assembly from said first section to said second section as said tool moves from said closed to open positions;
whereby, as said tool moves from said closed to said open position, said piston actuation means moves said piston assembly from said first section to said second section as said fluid flows through said metering passageway wherein in said second section, said fluid freely flows past said piston assembly allowing said abutment faces on said mandrell and housing to collide and impart shock to said drill string.
16. A jar tool as in claim 15 wherein a further passageway is provided through said piston assembly, said further passsageway including a pressure relief valve, said pressure relief valve allowing passage of said hydraulic fluid through said piston assembly where a predetermined pressure on said hydraulic fluid is reached.
17. A jar tool as in claim 15 wherein a further passageway is provided through said piston assembly, said further passageway including a second pressure relief valve whereby said second pressure relief valve does not open until a predetermined pressure is reached.
18. A jar tool as in claim 15 and further including spring means within said housing acting on said piston assembly to retain said assembly on said shoulder means.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393583A CA1177058A (en) | 1982-01-06 | 1982-01-06 | Jar tool |
| EP83300016A EP0083961A3 (en) | 1982-01-06 | 1983-01-05 | Improved jar tool for drill strings |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393583A CA1177058A (en) | 1982-01-06 | 1982-01-06 | Jar tool |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1177058A true CA1177058A (en) | 1984-10-30 |
Family
ID=4121751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000393583A Expired CA1177058A (en) | 1982-01-06 | 1982-01-06 | Jar tool |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0083961A3 (en) |
| CA (1) | CA1177058A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5228507A (en) * | 1991-08-23 | 1993-07-20 | Marcel Obrejanu | Wireline hydraulic retrieving tool |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9814802D0 (en) * | 1998-07-09 | 1998-09-09 | Buyers Mark | Self-resetting impact mechanism |
| GB2362904B (en) * | 2000-05-12 | 2004-08-11 | Bd Kendle Engineering Ltd | Improved jar mechanism |
| WO2003048511A1 (en) | 2001-11-27 | 2003-06-12 | Weatherford/Lamb, Inc. | Hydraulic-mechanical jar tool |
| CN109441387A (en) * | 2018-12-20 | 2019-03-08 | 宁夏万殷机械制造科技有限公司 | A kind of well head flash hits device |
| CN113338832B (en) * | 2021-05-18 | 2023-10-20 | 四川伟创石油装备制造有限公司 | Hydraulic bidirectional jar |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2981336A (en) * | 1956-10-10 | 1961-04-25 | Johnston Testers Inc | Jar |
| US3209843A (en) * | 1962-09-11 | 1965-10-05 | Houston Engineers Inc | Hydraulic jarring tool with relief valve |
| US3405773A (en) * | 1966-08-05 | 1968-10-15 | Wayne N. Sutliff | Sleeve valve and oil well tool embodying the same |
| US3399741A (en) * | 1967-02-24 | 1968-09-03 | Schlumberger Technology Corp | Well jar |
| US3716109A (en) * | 1971-02-22 | 1973-02-13 | Jarco Services Ltd | Rotary jar |
| CA931136A (en) * | 1971-07-08 | 1973-07-31 | Mason Leonard | Jarring and bumping tool for use in oilfield drilling strings |
| US4076086A (en) * | 1977-01-06 | 1978-02-28 | Baker International Corporation | Fishing jar for accommodation of excess tensile load |
| CA1095499A (en) * | 1979-02-20 | 1981-02-10 | Luther G. Reaugh | Hydraulic drill string jar |
| US4261427A (en) * | 1979-10-15 | 1981-04-14 | Sutliff Wayne N | Long stroke jar bumper sub with safety sleeve |
-
1982
- 1982-01-06 CA CA000393583A patent/CA1177058A/en not_active Expired
-
1983
- 1983-01-05 EP EP83300016A patent/EP0083961A3/en not_active Ceased
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5228507A (en) * | 1991-08-23 | 1993-07-20 | Marcel Obrejanu | Wireline hydraulic retrieving tool |
| US5398753A (en) * | 1991-08-23 | 1995-03-21 | Obrejanu; Marcel | Wireline hydraulic retrieving tool and downhole power generating assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0083961A3 (en) | 1984-07-25 |
| EP0083961A2 (en) | 1983-07-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20020106 |