CN204041022U - A kind of twofold whirl water pumping gas production downhole tool - Google Patents

Abstract

The utility model discloses a downhole tool for compound swirl drainage and gas recovery, which comprises a fishing head located in the oil pipe, one end of the fishing head is equipped with a slip and a split ring, and four slips are evenly distributed on the fishing head. Above, its inner surface is a cone-shaped annular surface, and its outer surface is an arc-shaped surface. The whole of the spiral body is a solid cylindrical structure, and its outer circular surface is provided with a spiral belt. The inner wall of the fishing head is a gap with the spiral belt. The smooth inner wall of the sliding fit, the end of the helix located in the fishing head is connected to the joint through threads, the joint is radially provided with a groove communicating with the helical groove of the helix, and the other end of the joint is connected with a hollow restrictor , the other end of the restrictor is connected to the upper central pipe through a collar, and the upper central pipe is a hollow tubular structure as a whole, and a radial hole is opened on one side of its middle. The utility model realizes the eddy current movement of the gas-liquid two-phase flow in the natural gas well, improves the liquid-carrying capacity of the gas in the natural gas production, and prevents the occurrence of the problem of liquid accumulation at the bottom of the well.

Description

A Downhole Tool for Composite Cyclone Drainage and Gas Production

technical field

The utility model relates to a compound swirl downhole tool used for drainage and gas recovery in natural gas exploitation.

Background technique

1) Research significance and necessity

Natural gas production is always accompanied by the production of brine and hydrocarbon liquids, which are carried by natural gas from the bottom of the well to the surface in the form of small droplets. However, the formation pressure of domestic gas fields is low, and the gas production rate of a single well is low. With the continuous exploitation of natural gas, the liquid-carrying capacity of natural gas decreases, and liquid deposits in the wellbore. Fluid accumulation increases the back pressure, affects productivity, and even "drowns" the gas well. Therefore, there is a need for a technology to discharge the liquid produced in the formation to the wellhead during the gas production process, that is, the liquid drainage of the natural gas well to recover gas, so as to solve the problem of bottom-hole liquid accumulation.

2) Analysis of existing technologies

Existing drainage gas recovery technologies include optimized pipe strings, foam drainage, plunger lift, gas lift, mechanical pumping, downhole restrictor technology and other drainage gas recovery techniques. These methods are not only inefficient, but also require additional ground equipment, which not only increases the production cost, affects the production of gas wells, but also has poor effectiveness.

(1) Optimal pipe string: This method is used in the middle and late stages of development of gas wells with water. By adjusting and optimizing the inner diameter of the pipe string, the slippage loss of gas flow can be reduced, and the liquid carrying capacity of natural gas can be increased. The disadvantage of this method is that the liquid drainage volume of the gas well should not be too large, and the running depth cannot be too deep due to the limitation of the strength of the tubing. Because it is difficult to resume production after killing the well, it is required to be able to realize the tripping operation without snubbing when tripping the tubing string.

(2) Foam drainage: For gas wells with insufficient liquid-carrying capacity, this method injects a surfactant (foaming agent) into the bottom of the well from the wellhead to reduce the surface tension of the liquid and produce a large amount of relatively stable water-containing foam, which makes the bottom of the well accumulate liquid Easier to be drained off the ground. The disadvantage of this method is that when the amount of water produced is large, a large amount of chemical agents are needed, which is not economical. When the formation contains oil, it will play a role in eliminating foam and reduce the effect of foam drainage.

(3) Plunger lift: The plunger lift is to use the plunger as a fixed interface between the liquid and the lifting gas to prevent the channeling of the gas and the fall of the liquid. The movement of the plunger can not only use downhole energy, but also inject high-pressure gas from the surface to supplement energy. But its disadvantage is that the daily water production at the bottom of the well cannot exceed 50m ³ /d, the gas-liquid ratio must be greater than 500m ³ /m ³ , and the ground needs to be equipped with special wellhead devices.

(4) Gas lift: This method uses an external gas source or a compressor to inject high-pressure gas downhole to reduce the liquid density between the gas injection point in the well and the ground, so that the liquid in the well can be discharged from the ground more easily. The disadvantage of this method is that complex ground equipment is required and the cost is high.

(5) Mechanical pumping: This method is to lower the deep well pump to an appropriate depth below the liquid level of the wellbore, and drive the plunger of the deep well pump to reciprocate through the ground pumping unit and the sucker rod in the well to realize the discharge of the liquid in the well. The main disadvantage of this method is that the equipment investment is large, and the gas-liquid mixed multiphase flow in the well reduces the pump efficiency, and the sucker rod and the pump are easily damaged.

(6) Downhole choke: When formation natural gas passes through the orifice of the choke, its pressure drops, atomizes rapidly, and absorbs formation heat. The advantage of this method is that the formation heat energy can be used to heat the low-temperature natural gas after throttling, thereby reducing the throttling pressure and hydrate formation temperature, preventing the formation of hydrate blockage, and improving the safety of the gas production gathering and transportation system. But this method is not ideal for drainage and gas recovery.

Improvement of traditional technology---swirl technology:

In view of the above-mentioned technical shortcomings, the downhole swirl tool (also known as vortex tool) using swirl technology to realize drainage and gas recovery has attracted attention at home and abroad. The basic principle of this method is: the gas-liquid mixed flow from the bottom of the well enters the device, and after The spiral groove is ejected tangentially along the inner wall of the oil pipe at high speed, forming a high-speed vortex flow. Due to the vortex movement, the fluid rotates at a high speed. Under the action of centrifugal force, the heavier liquid is thrown to the tube wall to form an orderly liquid flow. The air flow is in the center of the tube to form an air column, so that the liquid can rise effectively and solve the problem of drainage. Liquid gas problem.

Existing swirl tools have the following types:

Type I: Installed at the bottom of the tubing and connected with the tubing in a threaded manner, the tubing must be lifted during installation, which has strict requirements on the well conditions at the bottom of the well, and is rarely used at present.

Type II: It adopts upper and lower threaded connections, and can be installed at any position in the middle of the tubing to reduce the requirements on the well conditions at the bottom of the well. However, when installing, the tubing still needs to be raised, which is rarely used at present.

Type III: The downhole eddy current tool is positioned and sealed by the coupling of the tubing. It is not necessary to lift the tubing during installation, which is convenient for fishing operations. It is widely used at present. However, this kind of swirling tool has been tested in the field in China, and it is found that its effect is not good. When the bottom hole pressure is low and the water content is high, the drainage effect will be significantly reduced. The reasons are as follows:

a. Since there is an annular space between the top edge of the helical groove of the swirl tool and the inner wall of the oil pipe, the gas-liquid mixed fluid in this area does not perform spiral motion, so its rapid rise will destroy the vortex discharged by the helical groove, thereby reducing the liquid drainage effect;

b. As a gas well is generally installed with a restrictor, and the swirl tool can only be installed on its upper part, there is a certain distance between the two, so that on the one hand, there is a pressure loss in the restrictor, which reduces the inlet pressure of the swirl tool, and Liquid droplets are formed when the mist flows from the outlet of the restrictor to the inlet of the swirl tool, which reduces the use effect of the swirl tool.

3) The main idea of the utility model patent

Analyzing the existing downhole swirl tools, the main disadvantage is that there is an annular space between the helical belt and the inner wall of the tubing, which destroys the swirl flow that has been formed. In addition, there are liquid droplets instead of mist flow at the inlet of the swirl tool, which makes the swirl effect less Difference. Therefore, the utility model patent mainly solves the above problems, eliminates the fluid in the outer annular space of the spiral belt, and adds a restrictor at the inlet of the spiral belt to form a mist flow, which greatly improves the swirl effect, so this device can fundamentally solve the problem. The problem of poor drainage and gas recovery effect of existing tools. In addition, the device can replace the traditional downhole restrictor, and combine the cyclone and restrictor into one, reducing equipment cost.

Utility model content

The purpose of the utility model is to provide a downhole tool for composite swirl drainage and gas recovery, which can effectively solve the problems existing in the background technology.

In order to solve the existing problems in the background technology, it includes a fishing head 2 located in the oil pipe 1, and one end of the fishing head 2 is equipped with a slip 8 and a split ring 10, and four slips 8 are evenly distributed on the fishing head. 2, its inner surface is a cone-shaped annular surface, and its outer surface is an arc-shaped surface. The whole of the spiral body 3 is a solid cylindrical structure, and its outer surface is provided with a spiral belt. The inner wall of the fishing head 2 is the same as The smooth inner wall of the helical band is slidingly fitted with a gap. The end of the helical body 3 located in the fishing head 2 is connected to the joint 4 through threads. The joint 4 is radially provided with four grooves communicating with the helical grooves of the helical body 3. The other end of the throttle is connected with the hollow restrictor 5, and the other end of the restrictor 5 is connected with the upper central pipe 7 through the collar 6. The upper central pipe 7 is a hollow tubular structure as a whole, and one side of the middle A radial hole is provided, and a shearing pin 11 is installed in the radial hole, and a circle of first shoulders which are slidably matched with the inner cylinder 17 extend outward near the bottom of the upper central tube 7, and are sleeved on the upper central tube 7. One end of the upper spring 19 on the pipe 7 abuts on the first shoulder, and its other end abuts on the second shoulder of the lower center tube 21, and the second shoulder is positioned at the end of the lower center tube 21 and is connected with The inner cylinder 17 is slidingly fitted with clearance, one end of the lower central tube 21 abuts against the end of the upper central tube 7, and the other end passes through the inner cylinder 17 and the outer cylinder base 22, and the lower central tube 21 is covered with a lower Spring 20, one end of the lower spring 20 is pushed against the second shoulder, and the other end is pushed against the inner side of the inner cylinder 17. The inner cylinder 17 is a hollow tubular structure as a whole, and the other end is screwed and fixed on the lower push ring 16, the lower push ring 16 is integrally sleeved on the upper central tube 7, and a circle of concentric bosses extends outward from the other end, and a ring of upper push rings that move along the axial direction of the boss is set on the boss. Ring 15, the lower push ring 16 is screwed to the lower center tube 17, the front end of the lower push ring 16 is screwed to the slip seat 9, and the slip seat 9 as a whole is sleeved and slidably matched with the upper center tube 7 The hollow conical structure, its conical surface fits with the conical reaming hole in the card seat, and one end at the top of the cone extends outwards a circle of sleeve that fits with the sleeve, and the front end of the sleeve is installed on the The shear pin 11 in the radial hole is plugged and fixed, and a circle of outer cylinder 18 is arranged on the outside of the inner cylinder 17, and one end of the outer cylinder 18 is connected with the outer cylinder base 22 by threads, and the outer cylinder base 22 is connected with the lower center The tube 21 is sleeved and fitted, and the other end of the outer cylinder 18 is sleeved on the upper push ring 15 .

The outer end of the outer cylinder base 22 is sleeved with a nut 24 screwed and fitted with the lower central tube 21 , and a set screw 23 is provided between the nut 24 and the outer cylinder base 22 .

A ring of rubber cartridge seat 13 is fixed on the outer side of the upper push ring 15 , and a ring of lower sealing rubber cartridge 14 is fixed on the side of the rubber cartridge seat 13 close to the outer cylinder 18 .

A bottom ring extends outward from the bottom of the slip seat 9 , and the bottom ring is located on a side close to the rubber tube seat 13 and is fixed with a ring of upper sealing rubber tube 12 .

Due to the adoption of the above technical scheme, the utility model has the following beneficial effects: realizing the eddy current movement of the gas-liquid two-phase flow in the natural gas well, improving the liquid-carrying capacity of the gas in the natural gas production, and preventing the occurrence of bottom-hole liquid accumulation.

Description of drawings

In order to illustrate the utility model more clearly, the embodiments will be briefly introduced below in conjunction with the accompanying drawings.

Fig. 1 is a structural diagram of the utility model not set on the inner wall of the oil pipe;

Fig. 2 is a structural diagram of the utility model being set and sealed on the inner wall of the oil pipe.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the utility model easy to understand, the technical solutions in the utility model embodiment will be clearly and completely described below in conjunction with the accompanying drawings in the utility model embodiment.

Example 1

Referring to Fig. 1-2, it includes a fishing head 2 located in the oil pipe 1, and one end of the fishing head 2 is equipped with a slip 8 and a split ring 10, and four slips 8 are evenly distributed on the fishing head 2. The inner surface is a cone-shaped annular surface, and the outer surface is an arc-shaped surface. The spiral body 3 is a solid cylindrical structure as a whole, and its outer surface is provided with a spiral belt. The inner wall of the fishing head 2 is for sliding with the spiral belt. Matching smooth inner wall, one end of the helix 3 located in the fishing head 2 is connected to the joint 4 through threads, and the joint 4 is radially provided with four grooves communicating with the helical groove of the helix 3, and the other end of the joint 4 is connected to the helical groove. The hollow restrictor 5 is connected, and the other end of the restrictor 5 is connected with the upper central pipe 7 through a collar 6. The upper central pipe 7 is a hollow tubular structure as a whole, and one side of the middle is provided with a radial A shear pin 11 is installed in the radial hole, and a circle of first shoulders slidingly fit with the inner cylinder 17 is extended outward near the bottom of the upper central tube 7, and the upper central tube 7 is sleeved One end of the upper spring 19 abuts on the first shoulder, and the other end abuts on the second shoulder of the lower central tube 21. The second shoulder is located at the end of the lower central tube 21 and has a gap with the inner cylinder 17. Sliding fit, one end of the lower central tube 21 abuts against the end of the upper central tube 7, and the other end passes through the inner cylinder 17 and the outer cylinder base 22, the lower central tube 21 is covered with a lower spring 20, the One end of the lower spring 20 is pushed against the second shoulder, and the other end is pushed against the inner side of the inner cylinder 17. The inner cylinder 17 is a hollow tubular structure as a whole, and its other end is screwed and fixed on the lower push ring 16. The lower push ring 16 is integrally sleeved on the upper central tube 7, and the other end extends outwards a ring concentric with the boss, and the boss is covered with a circle of upper push ring 15 that moves axially along the boss, so The lower push ring 16 is screwed to the lower center tube 17, and the front end of the lower push ring 16 is screwed to the slip seat 9. The slip seat 9 is a hollow conical shape that is sleeved and slidably matched with the upper center tube 7. Structure, its conical surface fits with the conical reaming hole in the card seat, and one end at the top of the cone extends outwards a circle of sleeve that fits with it, and the front end of the sleeve is installed in the radial hole The shearing pin 11 is plugged and fixed, and a circle of outer cylinder 18 is arranged on the outside of the inner cylinder 17. One end of the outer cylinder 18 is connected with the outer cylinder base 22 through threads, and the outer cylinder base 22 is socketed with the lower central tube 21. Matching, the other end of the outer cylinder 18 is sleeved on the upper push ring 15 .

The outer end of the outer cylinder base 22 is sleeved with a nut 24 screwed and fitted with the lower central tube 21 , and a set screw 23 is provided between the nut 24 and the outer cylinder base 22 .

A ring of rubber cartridge seat 13 is fixed on the outer side of the upper push ring 15 , and a ring of lower sealing rubber cartridge 14 is fixed on the side of the rubber cartridge seat 13 close to the outer cylinder 18 .

A bottom ring extends outward from the bottom of the slip seat 9 , and the bottom ring is located on a side close to the rubber tube seat 13 and is fixed with a ring of upper sealing rubber tube 12 .

Example 2

Referring to Fig. 1, when the downhole tool for composite swirl drainage and gas production is going downhole, it is pulled by the shoulder of the upper end of the helix body 3 (also called the throwing head). 3. The shear pin 11 is cut off. At this time, due to the joint action of the upper spring 19 and the lower spring 11 (both springs are compression springs), the lower central tube 21, the nut 24, the outer cylinder base 22, the outer cylinder 18, The rubber cartridge seat 13 and the slip seat 9 move upward, and when the slip seat 9 touches the slip 8, the slip 8 opens outwards and gets stuck on the inner wall of the tubing 1 to make the tool set, as shown in Figure 2 Show. Simultaneously, the upper sealing rubber cylinder 12 and the lower sealing rubber cylinder 13 are compressed and opened, and are tightly attached to the inner wall of the oil pipe 1 to play a sealing role, so that the gas-liquid two-phase fluid in the lower part of the tool can only enter the inner hole of the upper center pipe 7 .

Referring to Figure 2, the working process after the tool is set on the inner wall of the tubing:

After the tool is set on the inner wall of the tubing 1, its position is fixed. Since the fluid pressure in the lower part of the tool is greater than the fluid pressure in the upper part, the pressure difference will cause the slips 8 to be clamped on the wall of the tubing 1. The upper sealing rubber tube 12 and the lower sealing rubber tube 13 continues to be compressed and opened, and is close to the oil pipe 1 inner wall. The gas-liquid two-phase flow in the lower part of the tool enters the inner hole of the restrictor 5 from the inner hole of the lower central pipe 21 and the upper central pipe 7, and the gas-liquid two-phase flow flowing out through the inner hole of the restrictor 5 is a mist flow, and passes through the joint 4 The radial hole of the radial hole enters the spiral groove of the spiral body 3, and the fluid rotates while rising in the spiral groove, forming a high-speed vortex, and enters the oil pipe 1 from the spiral body outlet.

The process of getting out of the well during tool maintenance:

When the tool needs maintenance, lift the top of the fishing head 2, and the fishing head 2 will drive the slips 8 to move upwards. At this time, the slips will shrink inward, thereby loosening the inner wall of the tubing 1. The upper sealing rubber tube 12 and the lower sealing rubber tube 13 shrinks and no longer seals. After the slips 8 move up for a certain distance, they move up together with the slip seat 9. At this time, the whole tool is brought up to the wellhead to realize the process of pulling out the tool.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it It is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit of the technical solutions of the various embodiments of the present invention. and range.

Claims (4)

1. a twofold whirl water pumping gas production downhole tool, it is characterized in that it comprises the fishing head (2) being positioned at oil pipe (1), one end of described fishing head (2) is provided with slips (8) and split ring (10), four slips (8) circumference uniform distributions are on fishing head (2), its medial surface is conical surface ring surface, its lateral surface is arcwall face, described conveyor screw (3) entirety is solid cylinder body structure, its periphery is provided with hurricane band, the inwall of described fishing head (2) is the smooth inner wall with hurricane band clearance sliding fit, one end that described conveyor screw (3) is positioned at fishing head (2) is connected with joint (4) by screw thread, this joint (4) radial direction offers (4) individual groove be connected with conveyor screw (3) helicla flute, the other end of described joint (4) is connected with the restriction choke (5) of hollow, the other end of this restriction choke (5) is connected with upper center tube (7) by box cupling (6), described upper center tube (7) entirety is the tubular structure of hollow, side in the middle part of it offers radial hole, shear pin (11) is installed in this radial hole, the first convex shoulder of a circle and inner core (17) clearance sliding fit is extended outward near the bottom of described upper center tube (7), the one end being enclosed within the upper spring (19) on upper center tube (7) withstands on this first convex shoulder, its other end withstands on the second convex shoulder of lower center tube (21), the second described convex shoulder be positioned at lower center tube (21) end and with inner core (17) clearance sliding fit, one end of described lower center tube (21) is against the end of upper center tube (7), its other end is through inner core (17) and urceolus base (22), the upper cover of described lower center tube (21) has lower spring (20), one end of this lower spring (20) withstands on the second convex shoulder, its other end withstands on the inner side of inner core (17), described inner core (17) entirety is the tubular structure of hollow, its other end spins and is fixed in lower pushing ring (16), described lower pushing ring (16) entirety is enclosed within upper center tube (7), its other end extends outward the concentric boss of a circle, on this boss, cover has a circle along the upper pushing ring (15) of boss axially-movable, described lower pushing ring (16) spins with lower center tube (17) and is connected, this lower pushing ring (16) front end spins with slip spider (9) and is connected, this slip spider (9) is overall for be socketed with upper center tube (7) the hollow taper structure be slidably matched, its taper seat is socketed with the reaming of deck inner conical and coordinates, its one end being positioned at vertex of a cone place extends outward the sleeve that a circle coordinates with its socket, front end and shear pin (11) grafting be arranged in radial hole of this sleeve are fixed, the outside of described inner core (17) is provided with a circle urceolus (18), one end of this urceolus (18) is connected with urceolus base (22) by screw thread, this urceolus base (22) is socketed with lower center tube (21) and coordinates, the other end of described urceolus (18) is socketed in pushing ring (15).

2. a kind of twofold whirl water pumping gas production downhole tool according to claim 1, it is characterized in that the one end in described urceolus base (22) outside is socketed with the nut (24) coordinated that to spin with lower center tube (21), between this nut (24) and urceolus base (22), be provided with holding screw (23).

3. a kind of twofold whirl water pumping gas production downhole tool according to claim 1, it is characterized in that the outside of described upper pushing ring (15) is fixed with a circle glue tube base (13), this glue tube base (13) is positioned at and is fixed with a circle lower seal packing element (14) near the side of urceolus (18).

4. a kind of twofold whirl water pumping gas production downhole tool according to claim 1, it is characterized in that the bottom of described slip spider (9) extends outward a circle foundation ring, this foundation ring is positioned at and is fixed with cartridge (12) on a circle near the side of glue tube base (13).