RU2501042C2 - Bore-hole implosive source of seismic vibrations - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: source located in wells during their drilling during stops is used for allocation of objects in an area located in front of and around the well shaft being drilled at predicted reversed vertical seismic profiling or at borehole-to-borehole survey. A device includes a hollow housing, in the inner two-stage groove of which there installed with possibility of back-and-forth movement is an actuator piston with seals with a cleanup piston stock of implosive chamber. A cleanup piston return load is rigidly attached to upper end of the actuator piston stock. A movable sleeve with a piston and with seals is installed on the external two-stage groove so that it can move back and forth. An internal cavity under the sleeve is filled with oil and is connected in its upper part through holes and grooves to the below-piston cavity of the actuator piston of the cleanup piston. Longitudinal openings are made in lower part of the housing of reduced diameter. The chamber sleeve that is covered with a coupling from below, which is connected to the sleeve through a tight thread, is rigidly attached to the housing from below through the tight thread. A check valve preventing liquid penetration into the chamber is installed into an axial hole of the coupling. A lower load is rigidly attached to the coupling from below and provides as to the shape the vertical position of the chamber axis. Movable sleeve is rigidly attached from below to a compartment with a seismic receiver. The compartment is attached through a cable terminal to a load-carrying cable. The cleanup piston made so that it can move back and forth is sealed in the chamber sleeve and is rigidly attached with a seal from above to a hollow slide that is freely inserted and sealed in the hole of the shank rigidly fixed and sealed on the stock and restricted in axial movement with a lower flange of the shank. Inside the chamber under the cleanup piston there installed freely with a large radial gap is an anvil block that has an inner groove made in an axial hole and having the possibility of interacting with several spring-type grips rigidly fixed in lower part of the cleanup piston. Chamber openings are in an open position when the cleanup piston is in an upper extreme position. Working surface areas of the actuator piston of the cleanup piston and movable sleeve with a piston have been chosen so that pressure in an oil cavity at cable tension creates force on the cleanup piston, which exceeds force on it due to hydrostatic pressure. For this reason, at cable tension by means of a winch, first, cleanup of the chamber is performed, then, openings are opened, and hydraulic impact of liquid and anvil block against the coupling bottom takes place, and after that, the device is lifted above the working face. After the device is installed on the working face and cable weakness appears, the cleanup piston lowered to extreme lower position under action of the return load, where it is connected with spring grips to the anvil block. The compartment is provided with a seismic receiver that control the seismic station start as per the first obtained maximum signal, and after that, it transmits the reflected wave parameters received by it to the station.

EFFECT: achievement of seismic pulse repetition for many times at construction of wells during drilling breaks for performance of predicted reversed vertical seismic profiling or for borehole-to-borehole survey, at which allocations of objects are performed in the area located in front of and around the well shaft being drilled; everything is achieved without any additional work for lifting and lowering of a string using only an instrument winch; for its operation, the source does not require any supply to it of either electric energy, or hydraulic liquid.

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Description

The essence of the invention.

Usage: to create a shock wave at large depths of the sea and in wells. The source in the wells during their drilling during the breaks is used to highlight objects in the area located in front of and around the drilled wellbore with the predicted reverse VSP or with inter-well penetration.

The device comprises: a hollow body, in the internal two-stage groove of which, with the possibility of reciprocating motion, the drive piston with the piston rod for cleaning the implosive chamber is installed with seals. A stripping piston return load is rigidly attached to the upper end of the actuator piston rod. On the outer two-stage groove with the possibility of reciprocating motion, a movable sleeve with a piston is installed with seals. The internal cavity under the sleeve is filled with oil and in its upper part through openings and grooves is connected with the piston cavity of the stripping piston drive piston. In the lower reduced diameter of the housing part, longitudinal windows are made. From the bottom to the body on a sealed thread, the camera sleeve is rigidly fixed, which is closed from below by a sleeve connected to the sleeve on a sealed thread. A check valve is installed in the axial bore of the coupling to prevent liquid from entering the chamber. The lower load is rigidly attached to the bottom coupling, which ensures the vertical position of the camera axis in shape. The movable sleeve on top is rigidly attached to the compartment with the seismic receiver. The compartment through the cable lug is attached to the load-carrying cable. A reciprocating stripping piston is sealed in the chamber sleeve and is rigidly fixed from above to the hollow slider, which is freely inserted and sealed in the shank hole, rigidly fixed and sealed on the rod and limited in axial movement by the lower shank of the shank. Inside the chamber under the stripping piston, a striker is installed freely with a large radial clearance, which is made with an internal groove in the axial hole, which can interact with several spring hooks rigidly fixed to the bottom of the stripping piston. The windows of the chamber are in the open position when the stripping piston is in its highest position. The working area of the stripping piston drive piston and the movable sleeve with the piston are selected so that the pressure in the oil cavity when the cable is tensioned creates a force on the stripping piston exceeding the force on it from hydrostatic pressure. For this reason, when the cable is pulled with a winch, the chamber is first stripped, then the windows open and a hydraulic shock of the fluid and the hammer hits the bottom of the coupling and only then lift the device above the bottom. When setting the device to the bottom and the appearance of slack in the cable, the stripping piston under the action of the return load drops to its lowest position, where it is connected to the striker by spring grippers. A seismic receiver is installed in the compartment, which, according to the first received maximum signal, controls the starts of the seismic station and subsequently transmits the parameters of the reflected waves it received to the station.

EFFECT: achievement of repeated repetition of a seismic impulse during well construction during breaks in drilling for conducting predicted reverse VSP or for interwell transmission, in which objects are selected in the area located in front of and around the well being drilled. This is all achieved without additional work on lifting and lowering the column using only a logging winch. For operation, the source does not require the supply of either electric energy or hydraulic fluid.

Description of the invention:

The present invention relates to devices for exciting seismic waves from wells.

A well-known well source is RF patent N2166779, 05/10/2001 (Patent classes: G01V 1/135, G01V 1/52) selected for the prototype, comprising a housing, a cable electrical input, a controlled wedge clamp, a drive motor and a power exciter, made in the form of a camera with windows in the housing that overlap by means of an annular shutter, and is equipped with a reciprocating piston, the piston displacement drive being made as a spindle connected through a gearbox and a controlled coupling to the motor shaft, windows in the housing p located in the lower part of the chamber, and the shutter, preloaded by a spring, is fixed by a latch mated to the anchor of the trigger electromagnet, and a gas cavity is placed above the piston from the side opposite to the working chamber. This is a very complex mechanical device that uses an electric motor, a gearbox, a controlled on-off clutch, an electromagnetic way of turning the source on. To work with such a source, it is necessary to have a load-carrying power cable for supplying electrical energy

The objective of the invention is to achieve the production of multiple seismic impulses in wells during their construction at the time of a break in drilling when changing tools without using an electric and hydraulic drive.

A positive result is achieved by the fact that the device contains a hollow body, in the internal two-stage groove of which, with the possibility of reciprocating motion, the drive piston with the piston rod for cleaning the implosive chamber is installed with seals. A stripping piston return load is rigidly attached to the upper end of the actuator piston rod. On the outer two-stage groove with the possibility of reciprocating motion, a movable sleeve with a piston is installed with seals. The internal cavity under the sleeve is filled with oil and in its upper part through openings and grooves is connected with the piston cavity of the stripping piston drive piston. In the lower reduced diameter of the housing part, longitudinal windows are made. A casing is rigidly attached to the case above the windows, which forms an annular cavity around the camera with a cross section equal to the area of the internal cross section of the camera. From the bottom to the body on a sealed thread, the camera sleeve is rigidly fixed, which is closed from below by a sleeve connected to the sleeve on a sealed thread. A check valve is installed in the axial bore of the coupling to prevent liquid from entering the chamber. Moreover, the outlet openings from the non-return valve go above the lower end of the casing. This allows the device to work on clean fluid with a lower density than the fluid in the well, for example, oil, which is poured into the chamber before the descent. The lower load is rigidly attached to the bottom clutch in a shape that ensures the vertical position of the camera axis. The value of the load should provide a pressure in the oil cavity sufficient to move the stripping piston up without detaching the device from the bottom. As an example, consider a device with a stripping stroke of 0.4 m operating at a depth of 500 m. The diameter of the stripping piston is d _p = 0.1411 m.

Stripping piston area will be f _n = 3,14d _n ^2/4 = 0.0156 m ^2.

The required force on the piston stripping T = ΔP f _p = 78144 H.

When using as a load one (10 m long) UBT165, × 57.2 with a linear mass of 147.3 kg / m, we will have the weight of the stationary parts of the device of order G _n = 15000 H.

The ratio of the areas of the drive of the stripping piston should be greater than T / G _n = 5.2.

Accepted with a margin of 5.5.

The diameter of the drive inner rod take d _W1 = 0.03 m

The diameter of the inner drive sleeve take d _g1 = 0,128 m

Sectional area of the drive piston will sweep Δf _n1 = 3,14 (d _n1 ^{2/4 2} _n1 -d _w ^2/4) = 0.01215 m ^2.

The drive cross-sectional area of the outer slider will be Δf _p2 = f _p1 / 5.5 = 0.0022 m ² .

The diameter of the drive outer rod we take d _W2 = 0,146 m

Sectional area of the outer drive rod f _{w2 w2} = 3.14 ^2/4 = 0.0167 m ^2.

The cross-sectional area of the drive outer sleeve f _g2 = f _W2 + Δf _p2 = 0,0189 m ² .

The diameter of the outer drive sleeve will take d _g2 = 2 (f _g2 / 3,14) ^0,5 = 0,155 m

The pressure in the oil cavity P _m = G _n / Δf _p2 = 6.8 MPa.

Impact pressure P _beats = 41.1 MPa.

At a depth of 1000 m, to ensure the operability of the source, the load should be 2 times more, that is, it will be necessary to use 2 pipes (10 m long) UBT165 × 57.2 with a total weight of 3000 kg.

At a depth of 1000 m will be: the required force on the stripping piston T = ΔP f _p = 156287 H;

the pressure in the oil cavity P _m = G _n / Δf _p2 = 13.6 MPa; shock pressure P _beats = 41.1 MPa.

The movable sleeve on top is rigidly attached to the compartment with the seismic receiver. The compartment through the cable lug is attached to the load-carrying cable. A reciprocating stripping piston is sealed in the chamber sleeve and is rigidly fixed from above to the hollow slider, which is freely inserted and sealed in the hole of the shank, rigidly fixed and sealed on the rod, and is limited in axial movement by the lower shoulder of the shank. Inside the chamber under the stripping piston, a striker is installed freely with a large radial clearance, which is made with an internal groove in the axial hole, which can interact with several spring hooks rigidly fixed to the bottom of the stripping piston. The windows of the chamber are in the open position when the stripping piston is in its highest position. The working area of the stripping piston drive piston and the movable sleeve with the piston are selected so that the pressure in the oil cavity when the cable is tensioned creates a force on the stripping piston exceeding the force on it from hydrostatic pressure. For this reason, when the cable is pulled with a winch, the chamber is first stripped, then the windows open and a hydraulic shock of the fluid and the hammer hits the bottom of the coupling and only then lift the device above the bottom. When setting the device to the bottom and the appearance of slack in the cable, the stripping piston under the action of the return load drops to its lowest position, where it is connected to the striker by spring grippers. A seismic receiver is installed in the compartment, which, according to the first received maximum signal, controls the starts of the seismic station installed at the wellhead and subsequently transmits the parameters of the reflected waves received by it to the station.

During drilling, when lifting a tool for replacement, when it is necessary to conduct seismic predictive studies of the borehole zone below and to the side of the bottom, the device on the cable descends to the bottom. During the descent, the stripping piston under the action of the weight of the main load through a hydraulic connection in the cavities filled with oil is in its highest position. When setting the device to the bottom and the appearance of slack in the cable, the stripping piston under the action of the return load drops to its lowest position, where it is connected to the striker by spring grippers. In this case, the liquid from the chamber will be extruded into the annular cavity between the chamber and the casing. To start the device, it is necessary to start choosing a cable with a winch at maximum speed. In this case, pressure will be created in the oil cavity, which will begin to move the stripping piston up. When the piston moves from its lowest position upwards, it will hold the hammer by means of a spring grip. At the moment when the stripping piston starts to open the windows, the well fluid under pressure will burst into the cavity between the stripping piston and the striker and the flow pressure will disconnect the striker from the stripping piston and move the stripping piston together with the slider relative to the shank and the rod upward and open the windows sharply. Under the striker there will be a vacuum filled with liquid vapor. The firing pin, pushed by the fluid stream at high speed (at a depth of 500 m, it is approximately equal to 60 m / s), together with the stream will hit the bottom of the chamber. The fluid flow will stop abruptly, a hydraulic shock will occur, the kinetic energy of the fluid flow will be converted to the energy of the shock pressure, for the chamber of the above example, this will be a pressure of approximately 41.1 MPa. Using a striker increases the force of impact by several times, since the density of steel is almost 7.85 times higher than the density of water. It takes less than 0.01 s to fill the chamber in time. Water hammer occurs before the rod comes to its highest position, which guarantees the cable is protected from dynamic stress from water hammer. For the next start-up of the device, it is necessary to put it on the face, as described above. The presence of a casing, forming an annular cavity with a cross-sectional area equal to the area of the inner section of the chamber increases the mass of the moving stream, which increases the energy of exposure. Also, the casing and the upper position of the camera windows under it allows the device to work on clean liquid, since the working fluid will fall from the camera under the casing and then back, which will facilitate the working conditions of the device.

This device is simpler in its design and in managing the start-up and preparation for the next start-up in comparison with well-known analogues

Figure 1 shows a longitudinal section of the device at the time when it is on the bottom in the absence of tension in the cable.

The device comprises a hollow body 1, in the internal two-stage groove 2 of which, with the possibility of reciprocating motion, the drive piston 3 with the piston rod 4 of the piston 5 for stripping the implosion chamber 6 is mounted with seals. The load 7 of the piston 5 for stripping 5 is rigidly fixed to the upper end of the rod 4 of the actuator . A movable sleeve 9 with a piston 10 is installed on the outer two-stage groove 8 with the possibility of reciprocating movement. The inner cavity 11 under the sleeve 9 is filled with oil and in its upper part through holes 12, 13, 14 and the groove 15 is connected to the piston cavity 16 of the piston 3 piston drive 5 stripping. In the lower reduced diameter of the part 17 of the housing 1, longitudinal windows 18 are made 18. A casing 19 is rigidly fixed to the housing above the windows, which forms an annular cavity 20 around the chamber 20. From the bottom to the housing 1, the sleeve 21 of the chamber 6 is rigidly attached to the seal, which is closed by the sleeve 22 from below, connected to the sleeve 21 on a sealed thread. A check valve 23 is installed in the axial bore of the sleeve 22. Moreover, the outlet openings 24 from the check valve 23 extend above the lower end of the casing 19. The lower load 25 is rigidly attached to the coupling 22 from below. The movable sleeve 9 is rigidly attached to the compartment 26 with the seismic receiver 27. Compartment 26 through the cable lug 28 is attached to the load-carrying cable 29. The stripping piston 5 is reciprocally sealed in the sleeve 21 of the chamber 6 and is rigidly fixed from above to the hollow slider 30, which is freely inserted and sealed in the hole shank 31, rigidly fixed and sealed on the rod 4, and limited in axial movement by the lower shoulder 32 of the shank 31. Inside the chamber under the stripping piston 5, a striker 33 is installed freely with a large radial clearance, which is made with an internal groove 34 in the axial hole that interacts with several spring hooks 35 rigidly fixed in the lower part of the stripping piston 5.

In the drilling process when lifting the tool for replacement, when it is necessary to conduct seismic predictive studies of the borehole zone below and to the side of the bottom, the device on cable 29 descends to the bottom. During descent, the stripping piston 5 under the influence of the weight of the main load 25 through a hydraulic connection in the cavities filled with oil, is in its highest position. When setting the device to the bottom and the appearance of slack in the cable 25, the stripping piston under the action of the return load 7 is lowered to its lowest position, where it is connected by spring grippers 35 to the striker 33. In this case, the liquid from the chamber 6 will be extruded into the annular cavity 20 between the chamber 6 and the casing 19. The position when the device is on the bottom or bottom of the sea is shown in the drawing. To start the device, it is necessary to start choosing cable 29 with a winch at maximum speed. In this case, pressure will be created in the oil cavity, which will begin to move the stripping piston 5 with the help of the drive piston 3. At the beginning of the movement of the rod 4 upward, it will move relative to the slider 30 until the moment when the slider 30 rests against the shoulder 32. After that, the movement of the rod 4 with the piston 5 and the striker 33 upward will begin. When the piston 5 moves from its extreme lower position upwards, it will hold the hammer 33 by means of a spring grip 35. When the piston 5 begins to open the windows 18, the well fluid under pressure will burst into the cavity between the piston 5 and the hammer 33. This flow pressure will disconnect the hammer 33 from the piston 5, and the reactive force of the flow will move the piston 5 together with the slider 30 relative to the shank 31 and the rod 4 upward and will open the windows sharply. Under the striker 33, when it moves along with the liquid flow downward, there will be a vacuum filled with liquid vapor. The hammer 33, pushed by the fluid stream at high speed, will hit the bottom of the chamber along with the stream. The fluid flow will stop abruptly, a hydraulic shock will occur, the kinetic energy of the fluid flow will be converted to the energy of the shock pressure. For the next start-up of the device, it must be put to the bottom, as described above.

Claims (1)

A downhole source comprising a housing, a cable entry, an implosive chamber with windows, a stripping piston drive, characterized in that a drive piston with seals of the stripping piston of the implosive chamber is sealed with seals with the possibility of reciprocating movement into the hollow body, into the two-stage groove of the piston; to the upper end of the piston rod of the drive, the stripping piston return load is rigidly fixed; on the outer two-stage groove of the housing with the possibility of reciprocating motion mounted with seals movable sleeve with a piston; the internal cavity under the liner is filled with oil and in its upper part through radial holes and an internal groove with a height greater than the stroke of the stripping piston is connected with the sub-piston cavity of the stripping piston drive; moreover, the working areas of the drive piston and the movable sleeve are correlated so that the pressure in the oil cavity created by the cable tension creates a force on the stripping piston more than the force on it from the hydraulic pressure when the source is on the bottom; longitudinal windows are made in the lower reduced diameter of the housing part; a casing is rigidly fixed to the case above the windows, which forms an annular cavity around the camera with a cross-sectional area equal to the internal section of the chamber; from the bottom to the body on a sealed thread, the camera sleeve is rigidly fixed, which is closed from below by a sleeve connected to the sleeve on a sealed thread; a check valve is installed in the axial hole of the coupling, and the outlet openings from the check valve extend above the lower end of the casing; the lower load is rigidly attached to the bottom coupling; the top of the movable sleeve is rigidly attached to the compartment with the seismic receiver, which is connected via a cable lug to the load-carrying cable; a stripping piston with the possibility of reciprocating motion is installed and sealed in the chamber sleeve and rigidly fixed on top with a seal to the hollow slider, which is freely inserted and sealed in the hole of the shank, rigidly fixed and sealed on the rod, and limited in axial movement by the lower shoulder of the shank; inside the chamber under the stripping piston, a striker is installed freely with a large radial clearance, which is made with an internal groove in an axial blind hole that interacts with several spring hooks rigidly fixed to the bottom of the stripping piston.