CN1648406A - Surface gas injection pressurized oil recovery and liquid drainage gas recovery device and method - Google Patents

Abstract

The present invention relates to oil and gas extracting apparatus and method suitable for deep well and super deep well, and aims at raising the hydrocarbon reservoir yield via lowering the pressure in bottom of gas lift well and solving the artificial lift problem of various kinds of well. The technological scheme of the present invention includes: injecting high pressure air via ground pipe and oil jacket to pneumatic motors in well gas booster pump to drive motor pistons and pump pistons; pumping out well liquid via the opened sucking valve, pump barrel and opened draining valve; and exhausting the mixture of exhaust air and pumped well liquid via oil pipe to well head output pipe. The present invention has the advantages of both gas lift and staff pump, can lower the bottom pressure to level lower than gas lift, and is especially suitable for the artificial lift of low pressure low potential oil/gas well, deep well and super deep well.

Description

Surface gas injection pressurized oil recovery and liquid drainage gas recovery device and method

technical field

The invention relates to a device and method especially suitable for deep well and ultra-deep well for oil recovery and liquid drainage and gas recovery, which belong to the field of oil and natural gas exploitation.

Background technique

In the process of exploiting oil and natural gas, when the formation energy is sufficient, oil and gas wells can be produced by self-spraying; when the formation energy is reduced and the water content is not enough to maintain self-spraying production, it is necessary to supplement energy and switch to artificial lift production . Commonly used artificial lifting methods include: rod pump, gas lift, electric submersible pump, hydraulic piston pump, hydraulic jet pump, gas jet pump, hydraulic pneumatic pump, foam drainage, etc. At present, many oil and gas fields at home and abroad have entered the middle and late stages of development. With the continuous reduction of formation productivity, rising water cut and other complex situations, the difficulty of oil and natural gas extraction and production costs continue to increase, and production efficiency continues to decrease. There is an urgent need for oil and gas recovery technology Develop in the direction of multi-variety, high efficiency and energy saving. Rod pumps are the most widely used mechanical oil recovery method at home and abroad. Most wells in major oil fields in my country use rod pumps, but the sucker rods limit the use of rod pumps in deep and ultra-deep wells. Continuous gas lift has the advantages of wide range of fluid production, deep lifting depth, no mechanical wear parts downhole, and convenient operation and management. It is especially suitable for complex gas-liquid ratio, severe sand production, corrosive media, deep wells and directional wells. Gas lift has more advantages than other mechanical recovery methods for oil and gas wells with certain conditions. my country has initially formed a certain scale of gas lift production. Since continuous gas lift is only applicable to oil wells with high formation productivity and sufficient energy, the gas injection pressure and gas injection rate of oil wells and drainage gas production wells continue to increase as the water cut in oil and gas fields in my country increases and formation energy and formation productivity gradually decrease. The gas lift efficiency decreases accordingly. Under the original gas supply capacity conditions, the number of gas lift wells is gradually decreasing. Therefore, seek and explore new artificial lift technology, start with new ideas, study new artificial lift devices, form new industrial application products, study engineering design methods of new processes, diagnosis, monitoring and control methods, and form a A series of supporting technologies have become an urgent need for improving oil recovery in the late stage of oil and gas field development in my country and even abroad.

The artificial lift technology using fluid pressure transmission includes two categories: liquid and gas. Currently, hydraulic piston pumps and jet pumps are used for hydraulic transmission; chamber gas lift, hydraulic pneumatic pump, and gas jet pump are used for pneumatic transmission.

In 1932, the United States applied hydraulic piston pumps for oil production, and popularized them in the 1950s. The former Soviet Union began to use hydraulic piston pumps for oil production in 1974. In 1967, my country's Shengli Oilfield began to use hydraulic piston pumps for oil production. The hydraulic piston pump is pressurized by the ground power pump and then pumped into the well through the tubing or a special channel, and the motor is driven to reciprocate up and down to help the downhole plunger pump pump oil. The hydraulic piston pump is suitable for high oil-gas ratio, sand production, high Condensed oil, waxy, heavy oil, deep wells, deviated wells, and horizontal wells have strong adaptability.

In 1956, Camp and Winkler proposed adding chambers in gas lift wells to improve gas lift efficiency. This is a special intermittent gas lift - chamber gas lift, which uses a chamber much larger than the tubing area to lower the liquid level, thereby reducing the bottom hole pressure, and the formation fluid fills the chamber through the fixed valve at the bottom of the chamber during operation , the ground injection gas enters the chamber through the oil jacket annulus, and the liquid level in the chamber is lowered, so that the liquid enters the oil pipe from the hole on the insertion pipe extending into the bottom of the chamber. After the liquid is completely pressed into the oil pipe, the injected gas also enters the oil pipe Lift the liquid slug above it. The device is suitable for low-pressure, low-production wells, and can reduce the bottom hole pressure to close to the pressure of the wellbore gas column. Later, DeMoss improved this technology to solve the problem that the formation liquid cannot enter the chamber and the influence of formation gas on the chamber efficiency during the gas lift stage.

In 1980, in the eighth chapter of "Lifting Oil Recovery Technology" Volume II (Part 2), C.R.Ca-nalizo introduced an air pump. In 1994, M.Amani of the United States invented a hydraulic pneumatic pump. Chamber gas lifts are somewhat similar. The air pump introduced by Canalizo has an isolation piston between the well fluid in the pump barrel and the injected gas. The injected gas is injected into the downhole pump barrel through a special channel, and the piston is pushed to discharge the liquid at the other end of the piston in the pump barrel from the tubing. The injected gas will discharge all the liquid. After reaching the oil pipe, the gas discharge valve is opened, and the gas in the pump barrel is discharged from the annulus of the oil jacket. When M.Amani's hydraulic pneumatic pump is working, the injection gas is injected into the downhole pump barrel through a special channel, the liquid level in the pump barrel is lowered, and the liquid is expelled from the oil casing annulus. After the injection gas presses all the liquid into the oil casing annulus, Open the valve between the pump barrel and the oil pipe through the ground controller, and the injected gas is discharged from the oil pipe.

Compared with the hydraulic piston pump, the working principle of the gas booster pump device proposed by the present invention is greatly improved. The hydraulic piston pump uses ground injection liquid as the power to drive the downhole motor; Multiple air motors of the pump drive the pump piston to move the liquid in the pump barrel out of the wellhead. The process has both the advantages of gas lift and rod pumps. The difference between the gas booster pump device and the hydraulic pneumatic pump and chamber gas lift is that the injected gas of the hydraulic pneumatic pump and chamber gas lift directly acts on the liquid surface in the pump barrel or on the piston that separates the liquid from the injected gas, and pushes the gas The working gas of the booster pump acts on multiple air motors. The gas injection pressure required by the hydraulic pneumatic pump must be greater than the pressure of the well depth liquid column, while the gas booster pump uses low-pressure gas to pressurize the well fluid to the required discharge pressure or Well depth above the fluid column pressure.

Contents of the invention

The purpose of the present invention is: to overcome the deficiencies of the prior art, to improve the recovery rate of oil and gas reservoirs, to reduce the bottom hole pressure of gas lift wells to a lower level, which is beneficial to solve the problem of low pressure and low productivity oil and gas wells, deep wells and super wells. In order to solve the problem of artificial lift in deep wells, a surface gas injection pressurized oil recovery and liquid drainage gas recovery device and method are proposed.

In order to achieve the above object, the present invention adopts the following technical solutions: the ground gas injection pressurized oil recovery and liquid drainage gas recovery device is composed of a high-pressure gas source, a ground gas injection pipe, a wellhead, casing, tubing, a packer, a gas booster pump, Composed of production pipes, its features are: high-pressure gas wells or compressors and other high-pressure gas sources are connected to the wellhead through the ground gas injection pipe, and the gas injection pipe can be the annular space of oil pipe or oil casing; the casing extends from the wellhead to the bottom of the well, and the oil pipe is located in the In the tubing, the tubing and casing are connected to the Christmas tree at the wellhead, and the downhole tubing has a packer to separate the tubing annulus from the bottom of the tubing and the tubing; a gas booster pump is installed at the bottom of the tubing, and the injected gas in the tubing annulus can enter The power gas inlet of the pump motor, the pump end communicates with the bottom of the well; the production pipe is located at the wellhead, one end is connected to the wellhead tubing, and the other end is connected to the ground gathering pipeline.

The gas booster pump used in the surface gas injection pressurized oil production and liquid drainage gas production device is a cylinder consisting of multiple motors and pumps. The motor consists of a motor cylinder, a motor valve, a motor piston, a motor shaft, and a power gas inlet. The pump is composed of a pump barrel, a pump piston, a pump shaft, a pump suction channel, a pump suction valve, a pump discharge channel and a pump discharge valve. It is characterized in that: the motor is located on the upper part of the pump, and the motor and the pump are connected through a connecting shaft. The connecting shaft passes through the center of the circular sealing body separating the motor and the pump, connects the pump shaft and the motor shaft, and is connected between the motor cylinder and the pump barrel. Forms a seal; the motor piston is located in the motor cylinder and is used to separate the motor cylinder into two chambers above and below the piston, one of which is used as the power cylinder and the other as the exhaust cylinder, the center of the motor piston Connect the motor shaft, and multiple motors are connected through the motor shaft; the pump piston is located in the pump barrel, which is used to separate the pump barrel into two chambers, one above and below the piston, one of the chambers is used as a suction chamber, and the other One chamber serves as the discharge chamber and the center of the pump piston is connected to the pump shaft.

The working process of the method of the present invention is as follows: the high-pressure gas source enters the annular space of the oil casing through the ground gas injection pipe according to a certain gas injection pressure and gas injection volume, and reaches the power gas inlet of the downhole gas booster pump. The motor valve is a reversing valve for the power gas. When the motor valve is in the upper position, the power gas that drives the motor moves into each power cylinder of the motor, and pushes the motor piston to move upward (at the end of the exhaust cylinder). The exhaust gas of the exhaust cylinder passes through the exhaust air The discharge channel is discharged through the motor discharge valve; the movement of the motor piston drives the pump piston to one end of the liquid discharge chamber through the shaft, the pump suction valve of the liquid suction chamber is opened, and the well fluid is sucked into the suction liquid from the pump suction channel chamber, and the well fluid in the liquid discharge chamber is discharged from the pump discharge channel through the opened pump discharge valve. The exhaust gas discharged from the motor is mixed with the well fluid discharged from the pump and discharged to the oil pipe, and the mixed fluid is discharged from the oil pipe to the wellhead production pipe in the form of gas-liquid multiphase pipe flow.

When the motor piston reaches the upper end of the cylinder, the motor piston strikes the valve needle of the motor valve exhaust valve, the motor valve exhaust valve opens, and the high-pressure power gas in the lower chamber of the motor valve is discharged from the motor valve exhaust valve into the exhaust gas discharge channel, and the motor valve The force of the power gas on the upper end surface is greater than the force of the exhaust gas on the lower end surface, the motor valve moves downward and is in the lower position, the functions of the exhaust air cylinder and the power cylinder are exchanged, and the motor piston moves in reverse; the power air enters each power cylinder of the motor from the power air inlet , to push the motor piston to move downward, and the exhaust gas in the exhaust cylinder is discharged through the exhaust exhaust channel through the motor exhaust valve; when the motor piston reaches the lower end of the cylinder, the motor piston hits the valve needle of the intake valve of the motor valve, and the intake air of the motor valve When the valve is opened, the high-pressure power gas enters the lower chamber of the motor valve from the intake valve of the motor valve. The area of the lower end surface of the motor valve is larger than that of the upper end surface, and the force of the power gas on the lower end surface of the motor valve is greater than that of the upper end surface. superior. Such a cycle completes the reciprocating cycle of the motor, the reciprocating cycle of the motor piston drives the reciprocating cycle of the pump piston, and the role of the liquid suction chamber and the liquid discharge chamber are exchanged, thereby completing oil recovery and liquid discharge gas recovery.

When formation gas has a great influence on the efficiency of the pump, downhole gas anchors should be used, and exhaust pipes should be installed to discharge the gas separated from the downhole directly to the ground. The oil pipe can also be used as a gas injection pipe, and the oil jacket annulus is used as a mixed fluid production pipe.

Compared with the prior art, the present invention has the following beneficial effects: (1) It not only has the advantages of gas lift, but also has the advantages of rod pumps, and can reduce the bottom hole pressure to a lower level than that of gas lift, and is suitable for low pressure and low pressure. The conditions of productive oil and gas wells have strong applicability; (2) No sucker rods and special downhole and ground connection parts are required, especially suitable for artificial lift technology in deep and ultra-deep wells; (3) Steel wire or air circulation can be used Throwing operation, easy operation and management.

Description of drawings

Fig. 1 is a schematic structural view of the surface gas injection pressurized oil recovery and liquid drainage gas recovery device of the present invention. In the figure: 1. Production pipe, 2. Surface gas injection pipe, 3 oil pipe, 4. Casing pipe, 5. Packer, 6. Gas booster pump, 7. Production layer.

Fig. 2 is a schematic structural view of the gas booster pump device of the present invention. In the figure: 1. Motor discharge valve, 2. Power gas passage, 3. Pump body, 4. Exhaust air discharge passage, 5. Motor valve, 6. Motor valve exhaust valve, 7. Motor piston, 8. Motor shaft, 9. Channel, 10. Pump discharge channel, 11. Pump piston, 12. Pump discharge valve, 13. Pump suction valve, 14. Pump suction channel, 15. Motor valve intake valve, 16. Channel, 17. Power gas inlet

Detailed ways:

The present invention will be further described below in conjunction with accompanying drawing.

Example 1, the high-pressure gas source enters the oil casing annulus through the ground gas injection pipe 2 according to a certain gas injection pressure and gas injection volume, and reaches the power gas inlet 17 of the downhole gas booster pump 6 (Fig. 2), and injects high-pressure gas into the booster pump for more One end of an air motor pushes the motor piston 7 (Fig. 2) to move, and the other end of the motor piston 7 (Fig. 2) passes the exhaust gas from the channel 9 (Fig. 2) through the exhaust gas discharge channel 4 (Fig. 2) through the motor discharge valve 1 (Fig. 2) discharge. The movement of the motor piston 7 (Fig. 2) drives the pump piston 11 (Fig. 2) to move, the suction valve 13 at the suction end of the pump is opened, and the well fluid (arrow at the bottom of Fig. 2) enters the suction end of the pump barrel from the pump suction channel 14 (Fig. 2), and at the same time The discharge valve 12 (Fig. 2) at the pump discharge end is opened, and the pump piston 11 moves to discharge the well fluid at the pump discharge end from the pump discharge channel 10 (Fig. 2). (The arrow on the right in Figure 2.10) is mixed and discharged to the oil pipe 3, and the mixed fluid is discharged from the oil pipe 3 to the wellhead production pipe 1 in the form of gas-liquid multiphase pipe flow. When the motor piston moves to the end of one end of the motor, the injected gas enters the other end of the motor piston, and the motor piston moves in reverse, so that the cycle is completed, thereby completing oil recovery, liquid drainage and gas recovery. When formation gas has a great influence on the efficiency of the pump, downhole gas anchors should be used, and exhaust pipes should be installed to discharge the gas separated from the downhole directly to the ground. The oil pipe can also be used as a gas injection pipe, and the oil jacket annulus is used as a mixed fluid production pipe.

Embodiment 2, the working process of the gas booster pump is: see Fig. 2, the up stroke, the motor valve 5 is in the upper position, the power gas that promotes the motor movement enters each power cylinder of the motor from the power gas inlet 17 through the channel 16, and pushes the motor piston 7 Moving upward (at one end of the exhaust cylinder), the exhaust gas in the exhaust cylinder is discharged from the channel 9 through the exhaust exhaust channel 4 through the motor discharge valve 1; the motor valve is a reversing valve for power gas. When the motor piston 7 reaches the upper end of the cylinder, The motor piston 7 hits the valve needle of the motor valve exhaust valve 6, the motor valve exhaust valve 6 opens, the high-pressure power gas in the lower chamber of the motor valve 5 is discharged from the motor valve exhaust valve 6 into the exhaust gas discharge channel 4, and the motor valve 5 The force of the power gas on the upper end surface is greater than the force of the exhaust gas on the lower end surface, the motor valve 5 moves downward and is in the lower position, the functions of the exhaust cylinder and the power cylinder are exchanged, and the motor piston moves and reverses; Enter each power cylinder of the motor through channels 2 and 9, and push the motor piston 7 to move downward, and the exhaust gas in the exhaust cylinder is discharged from channel 16 through the exhaust gas discharge channel 4 and through the motor discharge valve 1; when the motor piston 7 reaches the lower end of the cylinder , the motor piston 7 hits the valve needle of the motor valve intake valve 15, the motor valve intake valve 15 opens, the high-pressure power gas enters the lower chamber of the motor valve 5 from the motor valve intake valve 15, and the area of the lower end surface of the motor valve 5 is larger than that of the upper On the end face, the dynamic gas force on the lower end face of the motor valve 5 is greater than that on the upper end face, the motor valve 5 moves upward and is in the upper position, and returns to the upper stroke, so as to complete the reciprocating cycle of the motor. The movement of the motor piston 7 drives the pump piston 11 to move to one end of the liquid discharge chamber through the shaft 8, the pump suction valve 13 of the liquid suction chamber is opened, and the well fluid is sucked into the liquid suction chamber from the pump suction channel 14, The well fluid in the liquid discharge chamber is discharged from the pump discharge channel 10 through the opened pump discharge valve 12, the reciprocating motion of the motor piston 7 drives the reciprocating motion of the pump piston 11, and the functions of the liquid suction chamber and the liquid discharge chamber are exchanged. .

Claims (4)

1. A surface gas injection pressurized oil production and liquid drainage gas production device and method, characterized in that high pressure gas sources such as high pressure gas wells or compressors are connected to the wellhead through a ground gas injection pipe, and the gas injection pipe can be oil pipe or oil casing loop Space; the casing extends from the wellhead to the bottom of the well, the tubing is located in the casing, the tubing casing is connected to the Christmas tree at the wellhead, and the downhole tubing has a packer to separate the tubing annulus from the bottom of the well and the tubing; the bottom of the tubing is installed with gas The booster pump, the injected gas in the casing annulus can enter the power gas inlet of the pump motor, and the pump end is connected to the bottom; the production pipe is located at the wellhead, one end is connected to the wellhead tubing, and the other end is connected to the ground gathering pipeline. 2. The device and method according to claim 1, characterized in that: the gas booster pump used is a cylinder consisting of a plurality of motors and pumps; the motor is located on the top of the pump, and the motor and the pump are connected through a shaft Connected, the connecting shaft passes through the center of the circular sealing body that isolates the motor and the pump, connects the pump shaft and the motor shaft, and forms a seal between the motor cylinder and the pump barrel; the motor piston is located in the motor cylinder, separating the motor cylinder into upper and lower Two chambers, one chamber is used as a power cylinder, and the other chamber is used as a exhaust cylinder. The center of the motor piston is connected to the motor shaft, and multiple motors are connected through the motor shaft; the pump piston is located in the pump barrel, which divides the pump barrel into two parts: There are two chambers, one chamber is used as a liquid suction chamber, and the other chamber is used as a liquid discharge chamber, and the center of the pump piston is connected to the pump shaft. 3. The device and method according to claim 1, characterized in that: the high-pressure gas source reaches the wellhead through the ground gas injection pipe, injects into the annular space of the oil casing, and enters the power gas inlet of the downhole gas booster pump, and the high-pressure gas is charged into the booster pump One end of multiple air motors pushes the motor piston to move; the motor piston moves to drive the pump piston to move, the pump suction valve opens, the well fluid enters the suction end of the pump barrel, and the pump discharge valve opens at the same time, the well fluid enters the pump discharge port; The gas and the well fluid discharged from the pump are mixed and discharged to the oil pipe, and the mixed fluid is discharged from the oil pipe to the wellhead production pipe in the form of gas-liquid multiphase pipe flow. 4. The device and method according to claim 1, characterized in that: when the formation gas has a great influence on the efficiency of the pump, a downhole gas anchor should be used, and an exhaust pipe should be installed to directly discharge the gas separated from the downhole to ground.

Images