CN219795196U - Under-pressure coal bed gas reservoir full-horizontal well section negative pressure sand fishing pump - Google Patents

Abstract

The utility model provides a negative pressure sand fishing pump for an all-horizontal well section of an undervoltage coal bed methane reservoir, which comprises a power oil pipe, a liquid discharge short circuit, a top valve, a piston, a sand setting pipe, a broken sand pushing short circuit, a bottom valve, a rotary short circuit and a sand shovel which are connected in sequence; at least one roller centralizer is sleeved at the position of the power oil pipe at the two opening positions, and a large friction centralizer is sleeved outside the sand setting pipe; a plurality of first sand blocking rings are arranged in the sand setting pipe. According to the utility model, through the large friction force centralizer, the friction force can be increased while the bottoming friction loss of the sand setting pipe is ensured, the effective stroke of the piston is ensured, and the suction amount of well fluid is increased each time; a first sand blocking ring is arranged in the sand setting pipe, so that well fluid is turbulent in the sand setting pipe, has enough time for precipitation and is uniformly dispersed in the sand setting pipe, and the problem that the upper opening and the lower opening of the sand setting pipe are easy to block is solved; adopt rotatory short circuit, can guarantee that the sand shovel pastes tight sleeve pipe lower part all the time, keep sand shovel high-efficient work.

Description

Under-pressure coal bed gas reservoir full-horizontal well section negative pressure sand fishing pump

Technical Field

The utility model relates to the technical field of development of coalbed methane, in particular to a negative pressure sand fishing pump for an all-horizontal well section of an undervoltage coalbed methane reservoir.

Background

In the drainage and production process after the fracturing transformation of the coal-bed gas well, stratum sand, fracturing sand and coal dust can enter a shaft along with stratum fluid, so that the shaft is blocked, a drainage and production pump is worn, the pump is blocked and the like, and gas production is led to go into the well. By adopting the hydraulic flushing method, accumulated sand and accumulated powder of a shaft can be flushed and carried to the ground by means of liquid flowing circularly at high speed, however, because the reservoir pressure is very low after drainage, the water loss is serious in the well flushing process, the flow rate and the flow velocity of liquid returned in the shaft are very low, effective circulation cannot be established, sand and coal dust are difficult to flow back out of the shaft, and conversely, injected water can press coal dust and the like into the reservoir, so that the reservoir crack pollution and the yield are reduced. The mechanical sand-bailing pump is adopted, power is provided by an operation machine according to the principle of an oil pump, an oil pipe is used as a power shaft, a sand-depositing pipe is used as a sand storage pocket, the sand-bailing pump has a good use effect in wells with low stratum pressure and serious leakage, but can only be used in a vertical well or a well with a certain inclination due to the limitation of a mechanical structure, even if sand bailing of a horizontal well can be carried out by matching a corresponding sand-bailing pipe column at the lower end of the sand-bailing pump, the sand-bailing pump is limited by the displacement of the sand-bailing pump and the flow velocity, and the effective sand-bailing distance is limited. And the bailing work of the horizontal well is realized with the aid of the centralizer. The working principle of the centralizer is that the original surface contact of the pipe and the rod and the sleeve is changed into point contact, so that the friction force is reduced, the pipe and the rod are prevented from being worn, and the pipe and the rod can be conveniently put into the well. Therefore, the adopted centralizer is generally made of metal or alloy materials and has a smooth surface. Although the pipe rod can conveniently enter the horizontal well by adding the centralizer, when the piston is pulled back and forth, the sand setting pipe is easy to drive to move together, so that the stroke of the piston is shorter. In addition, in the repeated pumping process of the piston, the well liquid forms turbulence at the two ends of the sand setting pipe, so that the sand collection at the two ends of the sand setting pipe is more and the middle part is less. The sand setting pipes at the two ends of the sand powder plug have large running resistance of the piston, the sand fishing pump has to be lifted out of the well for cleaning, the space of the sand setting pipe is not fully utilized, and it is important that the frequent pump lifting and discharging is time-consuming and labor-consuming, the pump lifting at one time needs about 5 people to operate for 3 days, the pump discharging time is longer, and the cost is high.

Disclosure of Invention

The utility model aims to solve the technical problem of how to solve the problem of long-distance and high-efficiency horizontal well sand-pumping work.

The utility model solves the technical problems by the following technical means:

an under-pressure coalbed methane reservoir full-horizontal well section negative pressure sand fishing pump comprises a power oil pipe, a liquid discharge short circuit, a top valve, a piston, a sand setting pipe, a broken sand pushing short circuit, a bottom valve, a rotary short circuit and a sand shovel which are connected in sequence; at least one roller centralizer is sleeved at the position of the power oil pipe at the two opening positions, and a large friction centralizer is sleeved outside the sand setting pipe; a plurality of first sand blocking rings are arranged in the sand setting pipe.

According to the utility model, the roller centralizer is sleeved on the power oil pipe, the large-friction rubber centralizer is sleeved on the sand setting pipe, so that 'drag reduction before pump and drag increase after pump' are realized, the difference of front and rear friction is improved, the effective stroke of a piston of the sand-pumping pump is ensured, and the suction amount of well fluid at each time is improved; the first sand blocking ring is arranged in the sand settling pipe, so that well fluid is turbulent in the sand settling pipe, has enough time for precipitation and is uniformly dispersed in the sand settling pipe, the problem that the upper opening and the lower opening of the sand settling pipe are easy to block is solved, the utilization rate of the sand settling pipe is improved, the pumping frequency is reduced, and the cost is reduced; adopt rotatory short circuit, can guarantee that the sand shovel pastes tight sleeve pipe lower part all the time, keep sand shovel high-efficient work.

Further, the first sand blocking ring is inclined towards the outlet direction of the sand setting pipe.

Further, the device also comprises at least one second sand blocking ring, and the second sand blocking ring is positioned at the downstream of the first sand blocking ring.

Further, the second sand blocking ring is inclined in the opposite direction to the first sand blocking ring.

Further, the number of the second sand blocking rings is smaller than that of the first sand blocking rings.

Further, the included angle between the first sand blocking ring and the inner wall of the sand setting pipe and the included angle between the second sand blocking ring and the inner wall of the sand setting pipe are 30 degrees to 60 degrees.

Further, the heights of the first sand blocking ring and the second sand blocking ring are the same or different, and the included angles are the same or different.

Furthermore, the high-friction centralizer is made of rubber, and the diameter of the high-friction centralizer is smaller than the inner diameter of the sleeve.

Further, the top valve and the bottom valve have the same structure and comprise a valve seat, a spring and a valve core; the spring is positioned in the valve seat, one end of the spring is fixed with the valve seat, and the other end of the spring is fixed with the valve core; under the action of no external force, the spring pushes the valve core to block the inlet of the valve seat.

Corresponding to the device, the utility model also provides a negative pressure bailing method for the full horizontal well section of the under-pressure coal bed methane reservoir, which comprises the following steps:

(1) Before operation, determining parameters of a pump, the length of a sand setting pipe, the number of roller centralizers, the number of high-friction centralizers, a top valve and a bottom valve;

(2) Checking before operation, checking whether a piston, a rotary short joint and a sand shovel are good and effective, and checking whether a sand setting pipe is cleaned;

(3) Lowering the bailing pump pipe string through the hoisting equipment, and adding a roller centralizer when one half of the two-way depth is lowered; the sand scooping pump starts to enter the horizontal section, the sand shovel is always clung to the lower part of the sleeve, firstly, the accumulated sand and accumulated powder at the lower part of the sleeve are scooped up, the broken sand is pushed to short the sand so as to further clean and push the residual sand of the sleeve, and when the sand is accumulated to a certain extent, the ground lifting equipment can feel that the pump body is blocked, and the lowering is stopped;

(4) The pumping device is used for carrying out constant-speed reciprocating pulling piston movement on the sand pumping pump pipe string, when the power oil pipe is lifted, the top valve is closed, the bottom valve is opened, and well fluid carries sand powder into the sand setting pipe and is respectively stored between different sand blocking annular plates; when the power oil pipe is lowered, the bottom valve is closed, the top valve is opened, and the filtered well fluid returns to the oil sleeve annulus again through the top valve and the liquid drainage short circuit;

(5) Through the operation of reciprocating pulling the piston, sand powder continuously enters the sand setting pipe and is separated and stored, and when the piston is difficult to lift, the sand setting pipe is judged to be full of sand; the sand-bailing pump pipe string can be taken out of the shaft through the hoisting equipment, and the sand-setting pipe is immediately cleaned by adopting a forward and reverse vibration high-pressure water flushing method;

(6) And (5) circulating the steps (2) to (5) until the well section is completely horizontal.

The utility model has the advantages that:

according to the utility model, through the front pulley centralizer and the rear large friction centralizer, the bottom contact friction loss of the sand setting pipe can be ensured, the front and rear friction difference of the sand fishing pump is increased, the effective stroke of the piston is ensured, and the suction amount of each well fluid is increased; a first sand blocking ring is arranged in the sand setting pipe, so that well fluid is turbulent in the sand setting pipe, has enough time for precipitation and is uniformly dispersed in the sand setting pipe, and the problem that the upper opening and the lower opening of the sand setting pipe are easy to block is solved; adopt rotatory short circuit, can guarantee that the sand shovel pastes tight sleeve pipe lower part all the time, keep sand shovel high-efficient work, simultaneously, but when meetting firm barrier, sand shovel automatically regulated angle, pass through smoothly.

The utility model adopts the first sand blocking ring and the second sand blocking ring with opposite inclined directions, thereby ensuring that the well fluid further increases the turbulence effect before reaching the piston and improving the sand powder precipitation.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a sand pump according to embodiment 1 of the present utility model;

FIG. 2 is a schematic diagram of the bottom valve (top valve) in embodiment 1 of the present utility model;

FIG. 3 is a schematic view of the structure of the sand shovel and the rotary shorting in embodiment 1 of the present utility model;

FIG. 4 is a schematic diagram of the structure of the rotary joint, centralizer and casing according to embodiment 1 of the utility model;

fig. 5 is a schematic diagram showing the overall structure of the sand pump according to embodiment 2 of the present utility model.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described in the following in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The embodiment provides a negative pressure sand fishing pump for an all-horizontal well section of an undervoltage coal bed methane reservoir, which is shown in fig. 1 and comprises a power oil pipe 2, a liquid discharge short circuit 4, a top valve 5, a piston, a sand setting pipe 12, a broken sand pushing short circuit 14, a bottom valve 15, a rotary short circuit 16 and a sand shovel 17 which are connected in sequence; at least one roller centralizer 3 is sleeved on the power oil pipe 2, and a large friction centralizer 10 is sleeved outside the sand setting pipe 12; a plurality of first sand blocking rings 13 and second sand blocking rings 13' are arranged in the sand setting pipe 12. The second sand blocking ring 13' is located downstream of the first sand blocking ring 13. The first sand blocking ring 13 and the second sand blocking ring 13' can be perpendicular to the inner wall of the sand setting pipe 12, play a turbulent flow role, and accelerate sand deposition in the sand setting pipe 12. In the embodiment, the first sand blocking ring 13 is inclined towards the outlet direction of the sand setting pipe 12, and the inclination direction of the second sand blocking ring 13' is opposite to that of the first sand blocking ring 13. The factors influencing the two parameters, namely the pump displacement, the length of the sand setting pipe 12, the sand powder amount and the particle size, are mainly utilized by utilizing the included angle between the sand blocking ring and the inner wall of the sand setting pipe 12 and the height of the sand blocking ring. The angles and the heights of the multiple sand blocking rings can be the same or different, and the turbulence can be increased and the sedimentation can be accelerated by the different angles and the different heights.

Because the sand setting pipe 12 is longer, in order to make sand grains evenly dispersed in the sand setting pipe 12, the quantity of the second sand blocking rings 13 'is less than that of the first sand blocking rings 13, the inclined direction of the first sand blocking rings 13 is consistent with the flow direction of the sand grains, and the sand-water mixture flows to the downstream of the sand setting pipe 12 as much as possible while turbulent flow, and then sand powder is further precipitated under the action of turbulent flow in the direction of the second sand blocking rings 13', so that sand powder is prevented from being accumulated on the upstream of the sand setting pipe 12. In the embodiment, a first sand blocking ring 13 is arranged in the sand setting pipe 12 at 2/3 of the length, and the included angles between the first sand blocking ring 13 and the second sand blocking ring 13' and the inner wall of the sand setting pipe 12 are 30 degrees to 60 degrees. The specific angle can be obtained by comprehensively calculating the above various factors.

In this embodiment, the large friction force centralizer 10 is made of rubber, the diameter of the large friction force centralizer is smaller than the inner diameter of the sleeve, the bottom of the large friction force centralizer is in contact with the sleeve 1 under the action of weight, the top of the large friction force centralizer is not in contact with the sleeve 1, and water is circulated. The rubber centralizer can improve friction force with the sleeve 1 and avoid the sand setting pipe 12 from moving when the oil pipe 2 applies force.

In this embodiment, the top valve 5 and the bottom valve 15 have the same structure, as shown in fig. 2, taking the bottom valve 15 as an example, the top valve includes a valve seat 151, a spring 152, and a valve core 153; the spring 152 is positioned in the valve seat 151, one end of the spring is fixed with the valve seat 151, and the other end of the spring is fixed with the valve core 153; under the action of no external force, the spring 152 pushes the valve core 153 to block the inlet of the valve seat 151. In this embodiment, the valve core 153 is a sphere. The reciprocating motion of the piston is that the opening and closing of the top valve 5 and the bottom valve 15 are alternated, well liquid is sucked into the sand setting pipe 12, well liquid after sedimentation and filtration is discharged from the liquid discharge short circuit 4 and enters the casing pipe 1 for internal circulation.

In the embodiment, 1 roller centralizer can be arranged at each half of the two-opening depth, so that the eccentric wear between the power oil pipe and the two-opening casing pipe is reduced, and the friction resistance of the power oil pipe on the horizontal section of the casing pipe is reduced.

The liquid discharge short circuit function is to form pump internal and external circulation in one sand bailing section, and the fluctuation of the liquid level during operation is reduced.

The valve core of the top valve is connected with the valve seat by a spring, which is the key that the sand fishing pump can be put into the horizontal section; when the power oil pipe is lowered, the top valve is opened, and liquid in the pump enters the sleeve through the liquid discharge short circuit; when the power oil pipe is lifted up, the top valve is closed.

The sand blocking short circuit filters the pumped well liquid so that sand and coal dust can not enter the piston.

The rubber centralizer has the advantages that firstly, friction between the sand setting pipe and the sleeve is reduced to prolong the service life, and secondly, the piston can generate effective stroke when the power oil pipe is lifted and lowered.

The sand setting pipe is provided with a sand blocking annular plate with the length of 100-300 meters, and the sand blocking annular plate is used for separating sand and storing sand so as to reduce the flow of sand powder in the sand setting pipe when the sand setting pipe is lifted and lowered each time, reduce the risk of sand blocking short circuit and bottom valve blockage, and further increase the effective distance of one-time sand fishing; and immediately cleaning by adopting a forward and reverse vibration high-pressure water flushing method after each time of taking out the shaft.

The broken sand pushing short circuit has the functions of scraping residual sand powder on the inner wall of the sleeve and pushing the sand powder to the sand suction port, and providing certain friction resistance for the sand setting pipe.

The bottom valve is opened when the bottom valve is lifted up, and well fluid enters the sand setting pipe; when the sand setting pipe is lowered, the bottom valve is closed, the top valve is opened, and liquid in the sand setting pipe enters the sleeve through the piston rod and the liquid draining short circuit.

The sand shovel is connected with the upper part and is connected with the rotary short circuit, no matter how the sand setting pipe body rotates when the pump is started, the sand shovel is ensured to be always attached to the lower part of the sleeve. Can be lifted from the bottom of the sand bridge 18. In this embodiment, as shown in fig. 3 and 3, the structure of the rotary joint 16 includes a ball bearing 161, a sand shovel is fixed to an outer ring of the ball bearing, and an inner ring of the ball bearing is fixed to a bottom valve through a coupling head 162. A centralizer 163 is sleeved outside the outer ring of the ball bearing. When the sand dredger pump rotates in the lowering process, the gravity center of the outer ring is offset by the weight of the sand shovel, the outer ring rotates in the opposite direction, and the sand shovel is kept to be always positioned at the lower part of the sleeve. In addition, when the front part of the sand shovel bumps against a hard obstacle and cannot normally pass through the obstacle, the external force can drive the outer ring to rotate, so that the sand shovel automatically adjusts the gesture (angle) and smoothly passes through the obstacle. Fig. 3 is a top view, and the pointed design of the front end of the sand shovel 17 facilitates the shoveling of sand.

The sand bailing method for the device is as follows:

(1) Before operation, determining pump parameters, the length of a sand setting pipe 12, the number of roller centralizers 3, the number of large-friction centralizers 10, parameters of a top valve 5 and a bottom valve 15, the number of sand blocking loops, the height and an included angle; then serially connected in turn;

(2) Checking before operation, checking whether the piston, the rotary short circuit 16 and the sand shovel 17 are good and effective, and checking whether the sand setting pipe 12 is cleaned;

(3) The bailing pump pipe string is lowered through the hoisting equipment, and a roller centralizer 3 is additionally arranged when one half of the two-way depth is lowered; the sand scooping pump starts to enter the horizontal section, the sand shovel 17 is always clung to the lower part of the sleeve 1, firstly, the accumulated sand and accumulated powder at the lower part of the sleeve 1 are scooped up, the broken sand pushing short circuit 14 further cleans and pushes the residual sand of the sleeve 1 forwards, and when the sand is accumulated to a certain extent, the ground lifting equipment can feel that the pump body is blocked, and the lowering is stopped;

(4) The pumping device is used for carrying out constant-speed reciprocating pulling piston motion on the pumping string, when the power oil pipe 2 is lifted, the top valve 5 is closed, the bottom valve 15 is opened, and well fluid carries sand powder into the sand setting pipe 12 and is respectively stored between different sand blocking annular plates; when the power oil pipe 2 is lowered, the bottom valve 15 is closed, the top valve 5 is opened, and the filtered well fluid returns to the oil sleeve annulus again through the top valve 5 and the liquid drainage nipple 4;

(5) Through the operation of reciprocating pulling the piston, sand powder continuously enters the sand setting pipe 12 and is separated and stored, and when the piston is difficult to lift, the sand setting pipe 12 is judged to be full of sand; the sand-bailing pump pipe string can be taken out of the shaft through the hoisting equipment, and the sand-setting pipe 12 is immediately cleaned by adopting a forward and reverse vibration high-pressure water flushing method;

(6) And (5) circulating the steps (2) to (5) until the well section is completely horizontal.

Example 2

As shown in fig. 5, the difference between this embodiment and embodiment 1 is that a third sand blocking ring 13″ is further provided between the first sand blocking ring 13 and the second sand blocking ring 13', and the third sand blocking ring 13″ is perpendicular to the sand setting pipe 12, so that the later cleaning is facilitated. The first sand blocking ring 13 and the second sand blocking ring 13' only need 1 or 2 times.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (8)

1. The under-pressure coalbed methane reservoir full-horizontal well section negative pressure sand fishing pump is characterized by comprising a power oil pipe (2), a liquid discharge short joint (4), a top valve (5), a piston, a sand setting pipe (12), a broken sand pushing short joint (14), a bottom valve (15), a rotary short joint (16) and a sand shovel (17) which are connected in sequence; at least one roller centralizer (3) is sleeved at the two-opening position of the power oil pipe (2), and a large-friction centralizer (10) is sleeved outside the sand setting pipe (12); a plurality of first sand blocking rings (13) are arranged in the sand setting pipe (12).

2. An under-pressure coalbed methane reservoir full horizontal well section negative pressure sand fishing pump according to claim 1, wherein the first sand blocking ring (13) is inclined towards the outlet direction of the sand setting pipe (12).

3. An under-pressure coalbed methane reservoir full horizontal well section negative pressure sand fishing pump as claimed in claim 1 or 2 further comprising at least one second sand blocking ring (13 '), said second sand blocking ring (13') being located downstream of the first sand blocking ring (13).

4. A sub-pressure coalbed methane reservoir full horizontal well section negative pressure sand fishing pump according to claim 3, characterized in that the second sand blocking ring (13') is inclined in the opposite direction to the first sand blocking ring (13).

5. A sub-pressure coalbed methane reservoir full horizontal well section negative pressure sand fishing pump as claimed in claim 3 wherein the number of second sand retaining rings (13') is less than the number of first sand retaining rings (13).

6. An under-pressure coalbed methane reservoir full horizontal well section negative pressure sand fishing pump according to claim 4 is characterized in that the included angle between the first sand blocking ring (13) and the second sand blocking ring (13') and the inner wall of the sand setting pipe (12) is 30 degrees to 60 degrees.

7. The under-pressure coalbed methane reservoir all-horizontal well section negative pressure sand fishing pump according to claim 1 or 2, wherein the high-friction centralizer (10) is made of rubber, and the outer diameter is smaller than the inner diameter of the sleeve (1).

8. The under-pressure coalbed methane reservoir all-horizontal well section negative pressure sand fishing pump according to claim 1 or 2, wherein the top valve (5) and the bottom valve (15) have the same structure and comprise a valve seat (151), a spring (152) and a valve core (153); the spring (152) is positioned in the valve seat (151), one end of the spring is fixed with the valve seat (151), and the other end of the spring is fixed with the valve core (153); under the action of no external force, the spring (152) pushes the valve core (153) to block the inlet of the valve seat (151).