JPH0459436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new and useful improved fixing gear, and more particularly to a single-acting hydraulic fixing gear.

Fishing in oilfield terminology
means to remove from a well hole objects that do not belong to the well hole. The material to be removed is called "fish" and is part of the drill string stacked up when drilling an oil or gas well, or removed from an existing wellbore at the end of oil extraction or during a remediation process. This is the manufacturing equipment that should be used. The method already employed for removing the fish is to grasp the fish by some means and apply an axial strain to the means by pushing or pulling until the fish is obtained. A jar is a tool employed when drilling or manufacturing equipment is stacked so long that it cannot be removed by pushing or pulling it in a straight line from the ground surface.

A jar is typically placed within the drill string in the area of the stacked object so that a drilling rig operator at the surface can apply an impact force to the drill string by manipulating the drill string. be. The jar has a spline connection that allows relative axial movement between the inner mandrel and the outer housing without relative rotation.

The mandrel includes an impact surface or hammer;
The hammer contacts a similar impact surface or anvil on the housing when the jar reaches the limit of its axial travel. When these impact surfaces strike each other at high speeds, they create a very large impact on the fish due to the mass of the drill pipe above the jar.

Conventional jars are classified into three different types of jars: hydraulic jars, mechanical jars, and bumper jars. Bumper-type gears are primarily used to provide downward impact force. Bumper-type jars generally have spline connections that allow for sufficient axial movement so that as the drill pipe is moved up and down, the impact surfaces inside the jar impinge upon each other and apply a downward impact force to the fish. I'm starting to get it.

Mechanical and hydraulic jars differ from bumper-type jars in that they include a trip mechanism that retards the relative movement of the impact surfaces relative to each other until an axial strain is applied to the drill pipe. To drive the jar upward, the drill pipe is stretched by applying an axial tension force at the surface. This tensile force is carried by the jar's trip mechanism, which has a length sufficient to allow the drill pipe to extend and store potential energy.
When the jars are actuated, the stored energy as described above is converted to mechanical energy which causes the impact surfaces of the jars to impinge upon each other at high velocity. Hydraulic and mechanical jars are more efficient than bumper jars because they can provide a greater impact on the fish for a given drill pipe strain.

Mechanical jars generally have a narrower range of application and are less reliable than hydraulic jars. In some mechanical trip mechanisms, a trip load must be selected and preset at the surface in order to operate the jar at a particular load.
If it is necessary to increase or decrease the trip load, the drill pipe must be pulled out of the wellbore, a costly and time consuming procedure. In another known mechanical trip mechanism, torque is applied to the trip mechanism from the ground through the drill pipe, and the torque must be maintained during operation of the jar. Not only is this a danger to workers in the workplace, but it also makes it difficult to control trip loads in the case of a wellbore that deviates from a predetermined course. Another disadvantage of mechanical trip mechanisms is that they must be operated under a triggered condition. Thus, the trip mechanism is subjected to stress during normal drilling when it is operated as part of a bottom hole assembly. Furthermore, mechanical trip mechanisms have the disadvantage that the metal parts must move relative to each other under very high compressive loads. This causes premature wear and frequent failure of the moving parts.

Hydraulic trip mechanisms are even more desirable because they allow the impact load to be arbitrarily controlled solely by the amount of axial strain imparted at the ground surface. Additionally, hydraulic trip mechanisms are less susceptible to mechanical deformation and wear than mechanical trip mechanisms.
Therefore, it can be used for a longer period of time under the same conditions than a mechanical trip mechanism.

Patent documents disclosing hydraulic fitting gears have been primarily published within the past 30 years.

U.S. Pat. No. 3,349,858 discloses a single-acting (upward) hydraulic drilling gear in which the flow of crude oil past a piston is controlled by a flow control valve that provides constant flow control.

U.S. Pat. No. 3,735,827 discloses a hydraulic fixing gear that requires compressible pressure fluid. The mandrel is moved until the pressure fluid is compressed to a predetermined degree, at which point the control valve engages the adjustable trip line member, thereby causing the control valve to become compressed. is opened and pressurized fluid is discharged through the bypass passage, thereby allowing rapid movement of the hammer relative to the anvil surface.

U.S. Patent No. 3797591 includes U.S. Patent No. 3735827
A hydraulic fixing gear is disclosed that includes an adjustable trigger mechanism similar to, but distinct from, the trigger mechanism incorporated therein.

U.S. Pat. No. 3,851,717 has a constant flow bypass passage for the trip piston and is configured to drive the trip piston downward until the main bypass valve is opened and the jar is actuated. A hydraulic fitting gear is disclosed.

U.S. Patent No. 4,059,167 includes U.S. Patent No. 3,851,717
A fixing gear is disclosed which is similar to the gear disclosed in the above patent and incorporates a tandem piston arrangement for reducing the internal working pressure.

U.S. Patent No. 3,285,353 has two mandrels arranged in a tubular manner within an outer housing, one mandrel being connected to a drill string and the other mandrel being configured to be connected to a drill fixture. The fittings are disclosed. A piston valve is incorporated which is configured to reduce the pressure after a predetermined movement and drive the housing to impinge the surface of the hammer against the anvil surface.

U.S. Pat. No. 3,087,559 discloses a hydraulic fixing gear having a mechanical trip finger with a hydraulic delay means.

One object of the present invention is to provide a new and improved fixing gear useful in earth drilling operations for removing accumulated objects, i.e., fixings, from a drilled hole. .

Another object of the present invention is to provide a new and improved hydraulically controlled and driven fixing gear having an improved trip mechanism.

Another object of the present invention is to provide a new and improved single-acting hydraulic fixing gear configured to be easily reactivated and reactivated in the same direction. It is to provide.

A single-acting hydraulic fixing gear is disclosed that is configured for use in a tubular drill string to generate an upwardly directed gearing force to remove a fixing from a well. The jar is configured to be inserted into the wellbore on a drill string and connected to a fishing tool within the wellbore.

The fixing gear of the present invention includes an outer housing member and an inner housing member (mandrel) which are arranged in a cylindrical manner so as to be able to move relative to each other in the longitudinal direction, and one housing member is provided with a hammer. A member is provided, and the other housing member is provided with an anvil member. The housing member defines a chamber configured to contain a fluid that controls the jarring force. One end of the chamber is closed by a slidable seal that slidably supports an inner housing member, or mandrel, within the outer housing member. A piston is spaced apart from the sliding seal for movement within the pressure fluid chamber relative to the sliding seal. The pistons are arranged such that movement of the housing member in one direction relative to the other housing member drives the piston toward the sliding seal.

The chamber between the piston and the sliding seal has an outlet controlled by a valve element slidably supported on the mandrel. The predetermined relative movement of the housing member engages the valve element and drives it to the open position, thereby permitting fluid to flow out of the fluid chamber and substantially resisting further movement of the housing member. to exclude,
The hammer member carried by the mandrel is thus permitted to move into impactive engagement with the anvil member carried on the outer housing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

A single-acting fixing gear so long as to have to be shown in sections in the accompanying Figures 1A-1D is shown as a continuous longitudinal quarter section. Especially Figures 1A to 1
Figure D shows a half section in the longitudinal direction from the center line of the jar to its outer periphery. The fitting gear 1 includes a tubular inner mandrel 2 supported in a tubular manner within a tubular outer housing 3.
The mandrel 2 and the housing 3 consist of a plurality of segments, which will be explained in detail later.

The mandrel 2 includes a tubular upper member 4 having a longitudinal passage 5 therein (see Figures 1A and 1B). The upper end of the upper member 4 is enlarged in diameter as indicated by 6 and has an internal thread 7 for connection to a drill string or the like.
The lower end of the upper member 4 is also provided with a counterbore which extends to the internal shoulder 8 and is internally threaded 9 .

The middle part of the mandrel 2 consists of a tubular sleeve member 10 (see Figures 1B and 1C), which is inserted into the upper part 4 of the mandrel with its upper end abutting the shoulder 8. screw 9
It has an external thread 11 at its upper end so as to be screwed together and connected to it. The lower end of the sleeve member 10 is provided with external threads 12 (see FIG. 1C) and is provided with an internal bore or passageway 13 which communicates with a passageway 5 provided in the upper member 4 of the mandrel. The lower end of the mandrel 2 is a tubular member 1
4 (see Figures 1C and 1D),
The tubular member is provided with a counterbore extending to a shoulder 15 and having an internal thread 16. The tubular member 14 is assembled by screwing into the lower end of the sleeve member 10 with the lower end of the sleeve member 10 in contact with the shoulder 15.

The lower end of the tubular member 14 has a reduced diameter as indicated by the reference numeral 17, and the annular stopper shoulder 1
8 has been determined. Tubular member 14 has passages 5 and 1
3 and has an internal passageway 19 extending longitudinally. When the upper member 4, the sleeve member 10, and the tubular member 14 are screwed together as shown, the housing 3 is assembled as described later.
It constitutes a single tubular mandrel 2 which is longitudinally movable within the mandrel.

The housing 3, like the mandrel 2, is made up of several sections for easy assembly. The upper end of the housing 3 is made up of a tubular member 20 (see FIG. 1A), and the tubular member 20 has a smooth inner bore 21 at its upper end.
The outer surface 22 of the upper member 4 of the mandrel 2 is arranged longitudinally slidably within the inner bore. The lower end of the tubular member 20 has a reduced diameter section defining an annular shoulder 23 and having an externally threaded section 24 .

The housing 3 includes a tubular intermediate member 25 (see FIGS. 1A and 1B), which is provided with an internal thread 26 at its upper end for connection to the threaded portion 24 of the tubular member 20. There is. Intermediate member 2
The upper end of 5 comes into contact with shoulder 23 when tubular member 20 and intermediate member 25 are tightly fastened. The lower end of the intermediate member 25 has a reduced diameter portion defining a shoulder 27 and having an external thread 28 (see FIG. 1B).

The lower part of the housing 3 consists of a tubular member 29 (see Figures 1B, 1C, and 1D),
The tubular member has an internal thread 30 at its upper end for threaded connection with the external thread 28 of the intermediate member 25.
is provided. The upper end of the tubular member 29 comes into contact with the shoulder portion 27 when the intermediate member 25 and the tubular member 29 are tightly fastened. An internal thread 31 is provided at the lower end of the tubular member 29 (see FIG. 1D).

At the lower end of the housing 3 there is provided an elongated tubular connecting member 32 which is provided with an external thread 33 at its upper end and has a shoulder 34 . When the inner thread 31 and the outer thread 33 are tightly screwed together, the lower end of the tubular member 29 comes into contact with the shoulder portion 34. The connecting member 32 has a longitudinally extending internal passageway 35 that communicates with a passageway extending within the mandrel 2 and which connects the tubular member 14, the tubular member 29, and the connecting member 32.
It communicates with the annular space between the inner surface of the The lower end of the connecting member 32 has a reduced diameter as indicated by the reference numeral 36, and has an external thread 37 that is connected to a fish or the like so that it can function as a fitting jar.

As previously mentioned, the mandrel 2 and the housing 3 consist of several sections that are connected to each other by threading for easy assembly. The mandrel 2 is configured to be slidable within the housing 3. This fitting gear is filled with a suitable working fluid, e.g. a pressurized fluid, as will be explained later, and is therefore provided at several mounting points and at sliding engagement points between the mandrel 2 and the housing 3. A seal must be provided to prevent fluid from leaking.

As previously mentioned, the outer surface of the upper member 4 of the mandrel 2 is slidably fitted within the bore 21 of the tubular member 20 of the housing 3. The tubular member 20 is provided with an annular groove 38 on its inner circumferential surface, in which an O-ring 39 is arranged to seal the sliding connection to prevent leakage of pressure fluid. The threaded connection between the tubular member 20 and the intermediate member 25 is O
The O-ring 40 is sealed against fluid leakage by a ring 40 (see FIG. 1A), and is disposed within an annular groove 41 provided on the outer peripheral surface of the lower end of the tubular member 20. Similarly, the threaded connection between the intermediate member 25 and the tubular member 29 includes an O-ring 4
2 to prevent fluid from leaking (see FIG. 1B), and the O-ring 42 is disposed within a circular groove 43 provided on the outer peripheral surface of the lower end of the intermediate member 25. Further, the threaded connection between the tubular member 29 and the connecting member 32 is sealed with an O-ring 44 to prevent fluid from leaking (see Fig. 1D).
The O-ring 44 is disposed within an annular groove 45 provided at the upper end of the connecting member 32.

Seals similar to those described above are provided to prevent fluid from leaking through the threaded connections connecting the several sections of mandrel 2. Upper member 4 of mandrel 2 and sleeve member 1
0 is sealed by an O-ring 46 to prevent fluid from leaking (see FIG. 1B), and the O-ring 46 is connected to an annular groove 47 provided on the inner peripheral surface of the lower end of the upper member 4. located within.
Similarly, the threaded connection between the sleeve member 10 and the tubular member 14 is sealed against fluid leakage by an O-ring 48 (FIG. 1C), and the O-ring 48 is provided on the inner peripheral surface of the tubular member 14. It is arranged in an annular groove 49.

The spaces between the inner bores of the various parts of the housing 3 and the outer surface of the mandrel 2 allow pressurized fluid (or other suitable working fluid) in the fitting jar.
Closed chambers and passageways are provided for the flow of Various additional elements are provided as will be explained later. At the upper end of the tubular member 20, the inner bore 50 of the tubular member 20 and the outer surface 2 of the upper member 4
2, an annular chamber 52 is provided. A screw hole 53 is provided at the upper end of the annular chamber 52, and a plug member 54 having a threaded portion is fixed to the screw hole. Threaded bore 53 provides a means for introducing pressure fluid (or other suitable working fluid), as will be explained later.

The outer surface of the upper member 4 is slightly reduced in diameter at its lower end 55 and is provided with a plurality of longitudinally extending grooves 56 between which splines 57 are defined. (See Figures 1A and 2). The lower end of the tubular member 20 is provided with a reduced diameter inner bore 58 defining an angled upper shoulder 59 and extending longitudinally and circumferentially spaced apart from each other. It has a plurality of grooves 60, and the groove 60 has a plurality of splines 61 that fit into the groove 56 provided in the upper member 4.
(See Figures 1A and 2).

Groove 56 provided in upper member 4 and tubular member 2
The grooves 60 provided in the grooves 0 have a depth greater than the height of the splines 57 and 61 located within those grooves. Therefore, in FIGS. 1A and 2, the reference numeral 62
As shown at and 63, longitudinally extending passageways are defined within the respective grooves in the upper member 4 and the tubular member 20. The provision of longitudinally extending splines and grooves in the upper member 4 and the tubular member 20 provide a guide for longitudinal movement of the mandrel 2 within the housing 3 without rotational movement thereof. Passages 62 and 63 formed in the gaps between splines 57 and 61 and grooves 56 and 60 provide a means for pressurized fluid to flow between chamber 52 and the lower portion of the fitting jar, as will be explained below. is given.

In FIG. 1B, the gap between the intermediate member 25 and the upper member 4 is substantially larger than the fluid pressure chamber 52 and the fluid pressure chamber 6 is in communication with the fluid pressure chamber 52.
4 is defined as the gap. Tubular member 20
The lower end has an anvil surface 65 which is used when the illustrated lifting jar moves upwardly to lift an object out of the well. Intermediate member 25
The inner surface 66 of the fluid pressure chamber 64 defines a counterbore that extends a circumferentially extending shoulder 67 that is a stop to limit downward movement of the mandrel within the housing at the lower end of the fluid pressure chamber 64. It is determined that

The lower end 68 of the upper member 4 has an outer surface 55 with a threaded portion 69. A hollow cylindrical hammer 70 having an internal thread 71 is fixed to the threaded portion 69 of the upper member 4 by screwing, and is secured by a fixing screw (not shown) to prevent loosening even during operation of the device. It can be fixed. The upper end 72 of the hammer 70 is engageable with the anvil surface 65 of the tubular member 20 during actuation of the fixing gear.
The lower end surface 73 of the hammer 70 touches the shoulder 67 when the fixing gear is at the limit of its downward movement.
engage with. The intermediate member 25 has upper counterbores 7 extending to positions spaced a short distance apart from each other.
4 and a lower counterbore 75 defining an intermediate member 76 constituting a guide for guiding the movement of the mandrel.

The sleeve member 10 is provided with a plurality of longitudinally extending grooves 77 (FIGS. 1B and 1C).
(see Figure, Figure 3). Groove 77 defines a passage for pressurized fluid to flow as will be explained later. A tubular sleeve member 78 is tightly fitted into the sleeve member 10 and overlaps the upper end of the groove 77. The lower end of the sleeve member 78 has an enlarged diameter portion 79 whose sloping surface extends over the valve seat 80.
(See Figures 1B and 3).

The sleeve member 78 is provided at its upper end with a hole 81 that communicates and connects the counterbore 74 and the groove 77. The sleeve member 78 is also provided at its lower end with a hole 82 that communicates with the lower portion of the groove 77 and a fluid pressure chamber 83 and is controlled by a trip valve 84, which will be described later. The upper end of the sleeve member 78 is in contact with the lower end of the upper member 4. Valve seat 8
The lower end of the sleeve member 78 located below 0 is in contact with the upper end of the tubular sleeve member 85,
Sleeve member 85 is a tight fit over sleeve member 10 and covers the lower end of groove 77. Sleeve members 78 and 85 thus seal groove 77 and define a series of longitudinally extending passageways. The lower end of the sleeve member 85 is enlarged in diameter as indicated by reference numeral 86, and has a plurality of holes 87 communicating with the lower end of the groove 77.

Inner surface 88 of tubular member 29 and sleeve member 7
The outer surfaces of 8 and 85 are spaced apart from each other and define a fluid pressure chamber 83. The outer surface of sleeve member 85 is a smooth cylindrical surface to allow free movement of pressure piston 89, with trip valve 84 supported therebetween. The lower end of the sleeve member 85 has an enlarged diameter as shown at 90, and a groove 91 is provided on its outer surface. The upper end of the fluid pressure chamber 83 is sealed by an O-ring 92 disposed within an annular groove 93 in the guide portion 76 of the intermediate member 25.

At approximately the center of the fluid pressure chamber 83, the fluid pressure chamber 8
A trip valve 84 is arranged to control the flow rate of the pressure fluid flowing out from the valve 3 (FIGS. 1B and 5C).
(see figure). Trip valve 84 is a tubular valve element having a smooth cylindrical bore 94 that slidably fits along the outer surface of sleeve member 85.
Trip valve 84 is sealed on its inner surface by an O-ring 95 located within an annular groove 96. The trip valve 84 has a tubular extension 9 with an enlarged diameter.
7, and the extension has a counterbore 98. The counterbore 98 is connected to the fluid pressure chamber 83 by a hole 99 . Trip valve 8
4 has an inclined valve seat surface 100 connecting a smooth cylindrical bore 94 and a counterbore 98;
The valve seat surface 100 is adapted to abut the valve seat 80 when the trip valve 84 is in the closed position.

An annular pressure piston 8 is provided at the lower end of the fluid pressure chamber 83.
9 are arranged (see Figure 1C). The piston 89 is connected to the sleeve member 85 and the inner surface 8 of the tubular member 29.
O-ring 10 is slidably disposed between the O-ring 10 and the annular groove 102 on the outer surface thereof.
It is sealed by 1. The piston 89 has an orifice 104 and a longitudinally extending passageway 10.
It has 3. A groove 91 is formed in the enlarged diameter portion of the sleeve member 85, and the piston 89
is adapted to slide over the groove 91 to allow pressure fluid to flow therethrough. Piston 89 and trip valve 84
A compression coil spring 106 is disposed between the trip valve 84 and the piston 89 to urge the trip valve 84 to the closed position and the piston 89 to its initial position in contact with the shoulder 107.

Below the shoulder 107 against which the pressure piston 89 abuts, the outer surface 109 of the tubular member 14 and the tubular member 29
A fluid chamber 108 is defined by the inner surface 110 of (see FIG. 1C). The lower end of the fluid chamber 108 has an annular piston 1 slidably disposed within the fluid chamber.
11. The pistons 111 are arranged in annular grooves 114 and 115, respectively.
Rings 112 and 113 provide a seal against fluid leakage. The piston 111 abuts a spring 116 supported on the upper end 117 of the connecting member 32 and is biased upwardly by the spring. A threaded hole 118 closed by a plug 119 provides means for filling the fluid chamber 108 with fluid.

OPERATION The device described above is a single-acting, hydraulic fishing gear that may be used to apply an upward impact or jarring force to an object, or fish, stacked within a well. In operation, when the fixing gear generates an upward impact force, an axial tensile force is applied to the drill pipe at the earth's surface, thereby elongating the drill pipe. Resistance to such tensile forces is provided by a trip mechanism on the jar that is long enough to allow the drill pipe to stretch and store potential energy. When the jar reaches the trip position, the energy stored in the extended drill pipe is converted into mechanical energy that drives the impact surfaces of the jar, i.e., the hammer and anvil, toward each other and impinges at a high velocity. , which gives a very high impact force. When the upward extension of the drill pipe is released, the jar is returned to its initial or starting position. The device described above is a novel upwardly acting fixing gear and is actuated by fluid pressure. In order to make the invention easier to understand, the operating principles and order of movement of the various members will be explained.

Initial Position When the fitting jar 1 is assembled as described above, the jar will fit into the hole 53 provided in the tubular member 20.
The tubular member 29 is then filled with pressurized fluid through the hole 118 provided in the tubular member 29 . The pressure fluid used is preferably an incompressible fluid since the jar operates by exploiting the leakage of fluid past the pressure piston. The fitting gear may be operated using wellbore fluid so that the spacing between the members during operation can be adjusted to some extent. The working fluid is preferably an incompressible fluid, but compressible pressure fluids or high pressure gases may also be used. However, in this case, the travel distance required to pressurize the compressible fluid is greater, so a longer tool is required.

When the pressure fluid is introduced into the fixing jar 1 through the holes 53 and 118, it flows to the lowest part of the fluid chamber 108, which is closed by the pressure piston 111. The pressure fluid fills the space within the fluid pressure chamber 108 and the space within the fluid pressure chamber 83 provided between the pressure piston 89 and the O-ring 92.
Pressure fluid also fills various passageways, including passageway 77 and counterbore 74 leading to fluid pressure chamber 64 . Further, the fluid pressure chamber 64 and the fluid pressure chamber 52 are connected to the hole 53.
Filled with pressure fluid to a height of .

The fitting jar may be tilted to some extent in order to remove any air bubbles present in the pressure fluid, so that the fitting jar is completely filled up to the bore 53 with pressure fluid. At this point, plug 5
4 and 119 are inserted and the fitting jar is ready for use. The pressure piston 111 allows thermal expansion of the fluid, and the static pressure of the fluid in the wellbore and surrounding the jar is sufficient to cause the pressure fluid to flow completely from one section of the jar to another. Makes it possible to maintain pressure fluid in the jar below.

In the embodiment shown in FIGS. 1A-1D, the jar is in its initial or starting position, and the jar is in its initial position to create an upward impact force that facilitates loosening the fitting. driven upwards from the position. In this initial position, the hammer 70 is in contact with the shoulder 73. The pressure piston 89 is pushed against the shoulder 10 by the spring force of the spring 106.
7 is maintained in contact. In this initial position, spring 106 maintains trip valve 84 in a closed position against valve seat 80 (see FIG. 1B). Next, the operation of generating an upward impact force to loosen the fixing gear of the present invention will be explained.

Upward Jarring When the fixing gear 1 is actuated upwardly from the initial position shown in FIGS. 1A to 1D, the drill pipe to which the upper end 6 of the mandrel 2 is attached is extended upwardly to produce the desired position. brought into a state of tension. When the drill pipe is extended upwards, the mandrel 2 is also brought into tension and moves upwards to the limit allowed by the trip mechanism. When the mandrel 2 is moved upwardly from the initial position shown in FIGS. 1A-1D, the shoulder of the enlarged portion 86 of the sleeve member 85 first comes into engagement with the lower end of the pressure piston 89. In this position,
The shoulder portion of the enlarged diameter portion 86 and the piston 89 function as a valve that closes one end of the fluid pressure chamber 83, thereby preventing pressure fluid from flowing from the fluid pressure chamber 83 through a portion other than the passage 104. Thus, upward movement of the mandrel 2 does not initiate actuation of the trip valve 84 or impart pressure to the pressure fluid within the jar.

As the mandrel 2 moves further upwards, the shoulder of the enlarged portion 86 drives the pressure piston 89 upwards, applying pressure to the fluid in the fluid pressure chamber 83 . Pressure piston 89 due to the movement of mandrel 2
is driven further upwards, as the pressure fluid filling the fluid pressure chamber 83 is substantially incompressible;
Resistance to the movement of the mandrel is created. When the pressure piston 89 moves upward, the fluid pressure chamber 83
Pressure is applied to the fluid within the fluid pressure chamber, and the pressure of the fluid within the fluid pressure chamber suddenly becomes very high. Pressure fluid cannot flow past O-ring 92, nor can it flow past trip valve 84, which is closed at this stage of operation. The fluid in the fluid pressure chamber 83 can only leak very slowly through the passage 103 and orifice 104 provided in the pressure piston 89. This allows the pressure piston 89 to move upwardly at a speed determined by the amount of fluid leaking from the fluid pressure chamber 83 via the passageway 103. During this upward movement, the pressurized fluid within the fluid pressure chamber 83 is maintained under a very high pressure representing the pressure generated by the tension applied to the mandrel 2 by the drill pipe.

Further upward movement of mandrel 2 drives pressure piston 89 relative to tubular member 29 and O-ring 92. Such movement causes the fluid in the fluid pressure chamber 83 to flow through the orifice 104 and into the chamber 108.
This is accomplished by slowly leaking the fluid into the chamber 64 through the O-ring 92 and into the chamber 64 through the passageway 77. After the mandrel 2 has moved upward a predetermined amount, the fixing gear reaches a position where the upper end of the enlarged diameter portion 97 of the trip valve 84 engages the lower end 120 of the intermediate member 25. Although this position is not shown in the figure, it is an intermediate position just before the trip valve 84 is actuated.

At this point, the pressure fluid in the fluid pressure chamber 83 is under very high pressure and resists the movement of the pressure piston 89, thereby impeding the movement of the mandrel 2, which causes the mandrel and the drill pipe to A substantial amount of tension is generated. When the mandrel 2 moves further upward, the trip valve 84
is restricted from moving together with the mandrel, and the valve seat surface 100 of the trip valve 84 moves in a direction away from the valve seat 80, opening the trip valve 84.
In this position, the upper end of the enlarged diameter portion 97 of the trip valve 84 abuts the lower end 120 of the intermediate member 25. Trip valve 84 is opened and pressure fluid flows freely through holes 99 and 82, and the various passageways communicate with other fluid chambers 108, 64, 52.
When the trip valve 84 is opened, the fluid in the fluid pressure chamber 83 is transferred to other fluid chambers, mainly fluid chambers 108 and 6.
4, and the pressure within the fluid pressure chamber 83 is significantly reduced to the level of the static pressure within the wellbore.
This pressure drop removes the resistance to upward movement of the pressure piston 89 and
9 and mandrel 2 move quickly through the remainder of the gearing stroke.

Such rapid movement of the pressure piston 89 and mandrel 2 is the movement between the position where the trip valve 84 begins to open and the position shown in Figures 5A-5D. This movement is shown in Figures 5B and 5.
This is the movement when the trip valve 84 is wide open and the mandrel 2 is moved upwardly to the point where the upper surface 72 of the hammer 70 engages the anvil surface 65, as shown in FIG. The above-described rapid movement of mandrel 2 and pressure piston 89 releases tensile energy in mandrel 2 and the drill pipe in the form of mechanical energy that drives hammer 70 at high speed to collide with anvil surface 65. . At the time hammer 70 engages anvil surface 65, the fixing gear reaches its limit of upward movement. Thus, upward movement of mandrel 2 is limited by hammer 70 engaging anvil surface 65, and downward movement of mandrel 2 is limited by hammer 70 engaging shoulder 67, as described above. limited.

Return to Initial Position After Upward Jaring When the fitting jar reaches the limit of upward movement shown in Figures 5A-5D, the fitting jar releases the tension on the drill pipe. The mandrel 2 is then returned to its operational condition by allowing the mandrel 2 to return to the initial position shown in FIGS. 1A-1D. When the mandrel 2 moves downward, the hammer 70 moves away from the anvil surface 65. In this case pressure piston 8
9 moves downward together with mandrel 2. The fluid pressure chamber 83 is filled with pressure fluid that is forced through the hole 87, the passage 77, the hole 82, and the open trip valve 84 as the pressure piston 89 moves downward. As the mandrel 2 moves downward, the trip valve 84 closes the end 1 of the intermediate member 25.
This causes the trip valve 84 to close. As the downward movement of the mandrel 2 continues, the pressure piston 89 pushes the shoulder 10
7 and the valve formed by the pressure piston 89 and the enlarged diameter portion 86 of the sleeve member 85 is opened. The static pressure acting on the piston 111 forces the pressure fluid through the opened valve into the fluid pressure chamber 83, thereby ensuring that the fluid pressure chamber 83 is filled with pressure fluid. Further downward movement of the mandrel 2 causes the hammer 70 to engage the shoulder 67, thereby preventing further downward movement of the mandrel 2, as shown in FIGS. 1A-1D. Fluid chamber 108 and fluid chamber 5 until the fixing jar is returned to the initial position.
Pressure fluid is distributed between 2 and 64.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and it is understood that various embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art.

[Brief explanation of drawings]

FIGS. 1A to 1D are half-sectional views showing an embodiment of the single-acting hydraulic fixing gear according to the present invention divided into four parts in the longitudinal direction, respectively, in an initial position. Figure 2 is line 2- of Figure 5B.
FIG. 2 is a cross-sectional view showing a half section of the fixing gear along line 2; FIG. 3 is a cross-sectional view of a half section of the fixing gear taken along line 3--3 of FIG. 5B.
FIG. 4 is a cross-sectional view of the fixing gear half section taken along line 4--4 of FIG. 5C. Figures 5A-5D show the position of the fixing gear after the trip valve has been opened, the mandrel has completed its upward movement, and the hammer has impacted the anvil portion. 1D is a half-sectional view corresponding to the 1D view; FIG. 1...Fishing gear, 2...Mandrel, 3
...housing, 4...upper member, 5...passage, 7...internal thread, 8...shoulder, 9...internal thread, 10...sleeve member, 11...threaded part, 12...external thread, 13...passage,
14... Tubular member, 15... Shoulder, 16... Internal thread, 1
8...shoulder part, 19...passage, 20...tubular member, 21...
Inner bore, 22...Outer surface, 23...Shoulder, 24...Threaded part, 25...Intermediate member, 26...Inner thread, 27...Shoulder, 28...Outer thread, 29...Tubular member, 30, 31
...Inner thread, 32...Connection member, 33...Outer thread, 34
... Shoulder, 35... Passage, 37... External thread, 38... Annular groove, 39, 40... O-ring, 41... Annular groove, 42
...O-ring, 43...annular groove, 44...O-ring, 4
5... Annular groove, 46... O ring, 47... Annular groove, 4
8... O ring, 49... Annular groove, 50... Inner bore, 52... Chamber, 53... Hole, 54... Plug member, 5
5...Lower end, 56...Groove, 57...Spline, 58
...Inner bore, 59...Shoulder, 60...Groove, 61...Spline, 62, 63...Passway, 64...Fluid pressure chamber,
65... Anvil surface, 66... Inner surface, 67... Shoulder, 6
8...Lower end, 69...External thread, 70...Hammer, 71
...External thread, 72...Top end, 73...Bottom surface, 74...Top counterbore, 75...Lower counterbore, 76
...Intermediate member, 77...Groove, 78...Sleeve member, 7
9... Enlarged diameter portion, 80... Valve seat, 81, 82...
Hole, 83...Fluid pressure chamber, 84...Trip valve, 85...
Sleeve member, 86... enlarged diameter portion, 87...
Hole, 88...Inner surface, 89...Pressure piston, 91...
Groove, 92... O-ring, 93... Annular groove, 94... Bore, 95... O-ring, 96... Annular groove, 97... Extension part, 98... Counter bore, 99... Hole, 100... Valve seat surface, 101... O Ring, 102... Annular groove, 10
3... Passage, 104... Orifice, 106... Compression coil spring, 107... Shoulder, 108... Fluid chamber, 10
9...Outer surface, 110...Inner surface, 111...Piston, 1
12, 113... O-ring, 114, 115... Annular groove, 116... Spring, 117... Upper end, 118... Screw hole.

Claims (1)

[Scope of Claims] 1. Fluid-operated fitting gears assembled in a tubular manner so as to be able to move longitudinally within a limited range relative to each other, one of which is connected to a drill pipe and the other of which is connected to a drill pipe. a pair of tubular members configured to be connected to an object to be removed from a well; means for defining a chamber for retaining fluid between the pair of tubular members; and means for closing one end of the tubular member. a piston configured to engage and be driven by one of the tubular members, the chamber being filled with a fluid that resists relative movement of the piston; are adapted to move together with one of the tubular members to apply pressure to the fluid within the chamber when the two move in one direction relative to each other, and one of the tubular members is arranged to press the piston and the other end of the chamber. and a valve hole located between the pair of tubular members, and the valve hole is closed for a while after the pair of tubular members start relative movement in the one direction, and the piston moves a predetermined amount in the one direction. a valve that opens the valve hole to release fluid from the chamber when the piston undergoes the predetermined amount of relative movement, thereby substantially reducing resistance to further relative movement of the tubular member; a restricting passage means that allows fluid to flow out from the chamber at a minute flow rate between the chambers, and a restricting passage means provided in one and the other of the pair of tubular members to prevent an impact from occurring when the tubular members move relative to each other after the valve hole is opened. a fluid-operated fitting gear including a hammer and an anvil that engage the;