Multi-lithologic oil and gas reservoir oil and gas simultaneous production electric control pipe column and production method

Abstract

The invention discloses a multi-lithologic oil and gas reservoir oil and gas simultaneous production electric control pipe column and a production method, and belongs to the technology of oil and gas production from a multi-layer oil well, a packer I, a bottom-hole regulator and a packer II are sequentially arranged in a sleeve from bottom to top, the packer I, the bottom-hole regulator and the packer II are all of tubular structures, and middle channels of the packer I, the bottom-hole regulator and the packer II are liquid flow channels; the packer I, the bottom-hole regulator and the packer II are sequentially connected through connecting pipes; middle channels of the packer I, the bottom-hole regulator and the packer II are communicated to form a liquid channel, and gas channels are arranged on walls of the packer I, the bottom-hole regulator and the packer II and are communicated with one another. By using the electric control simultaneous production packer, the electric control simultaneous production bottom-hole regulator and the electric control gas lift valve, oil-gas sub-runner production and simultaneous production of multiple lithologic reservoirs are achieved, the problem that a high-pressure gas layer affects liquid production of a low-pressure oil layer is solved, gas lift oil production of the oil layer is achieved through high-pressure gas, and the yield of the oil layer is improved.

Description

Technical Field

[0001] The present invention belongs to the technology of producing oil and gas from multi-layer oil wells, and particularly relates to an electric-controlled pipe string for simultaneous production of oil and gas in multi-lithologic oil and gas reservoirs and a production method. Background Art

[0002] With the advancement of domestic onshore oilfield development technology, the depth of oil wells is advancing toward 10,000 meters. The developed reservoirs exhibit diverse lithologies and exhibit overlapping oil and gas layers, typically with upper oil layers and lower gas layers. To improve resource utilization, the common practice is to simultaneously develop both oil and gas layers, utilizing a rational production system for efficient development.

[0003] However, as the distance between reservoirs increases, lithology changes significantly, reservoir pressure and oil and gas physical properties differ significantly, and interlayer interference during production is severe. In particular, when the pressure of the lower gas layer is high, the well will not produce oil, reducing the development efficiency of the reservoir. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the existing technology and provides an electrically controlled pipe string and production method for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs. It is mainly suitable for simultaneous oil and gas production technology with a high-pressure gas layer at the bottom and a low-pressure oil layer at the top, solving the problem that the bottom high-pressure gas layer cannot be produced while the upper oil layer cannot be produced.

[0005] The present invention discloses an electrically controlled string for simultaneous oil and gas production in a multi-lithologic oil and gas reservoir, comprising a casing and an oil pipe. A packer I, a production distributor and a packer II are sequentially arranged in the casing from bottom to top. The packer I, the production distributor and the packer II are all tubular structures, and their intermediate passages are liquid flow passages. The packer I, the production distributor and the packer II are sequentially connected by connecting pipes. The intermediate passages of the packer I, the production distributor and the packer II are connected to form a liquid passage, and gas passages are provided on the walls of the packer I, the production distributor and the packer II and are connected.

[0006] As a further improvement of the present invention, the production distributor is composed of a central tube II and an upper joint and a lower joint integrated with its two ends. An axial gas bridge channel II is provided in the tube wall of the central tube II, and a radial liquid production channel is provided on the central tube II and connected to the middle channel II of the central tube II.

[0007] As a further improvement of the present invention, the air inlet and the air outlet at both ends of the gas bridge channel II are connected to the lower joint and the upper joint respectively.

[0008] As a further improvement of the present invention, an electrically controlled regulating switch valve is provided in the liquid production channel.

[0009] As a further improvement of the present invention, a flow meter is provided on the middle channel II of the central tube II.

[0010] As a further improvement of the present invention, an installation groove is opened on the upper tube wall of the production dispenser, and a thermometer and a pressure gauge are arranged in the installation groove.

[0011] As a further improvement of the present invention, the said seal I and seal II have the same structure, both of which are composed of a central tube I and joints I and II integrated with its two ends. The central tube I contains an intermediate channel I, and an axial gas channel I is provided in the tube wall of the central tube. A rubber sleeve is provided on the central tube I, and more than two radial gas external connection channels I are provided on the central tube I on one side of the rubber sleeve and are connected to the gas channel I. The other side of the rubber sleeve is provided with an electrically controlled sealing mechanism to drive the rubber sleeve to expand and contract.

[0012] As a further improvement of the present invention, the gas channel I on one side of the electric-controlled setting mechanism is connected to the connector II.

[0013] As a further improvement of the present invention, joint I of packer I is provided with a threaded plug to seal it, joint II is connected to the lower joint of the production distributor through a connecting pipe, the upper joint of the production distributor is connected to joint II of packer II through a connecting pipe, joint I of packer II is connected to the oil pipe, and an electric-controlled air lift valve is connected to the oil pipe; the intermediate channels I and II of packer I, production distributor and packer II are connected in sequence through oil pipe short-circuits.

[0014] The production method using the above-mentioned electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs comprises the following steps: (1) Connect the packer I, the production distributor, the packer II and the gas lift valve in sequence, lower the packer I to below the bottom of the low-pressure oil layer, lower the production distributor to the middle of the low-pressure oil layer, and lower the packer II to above the top of the low-pressure oil layer; (2) When power is turned on, the electric-controlled setting mechanism controls the rubber sleeve of Packer I to set the rubber sleeve, so that the rubber sleeve and the casing are sealed and gas does not rise from the casing; similarly, Packer II is also set at the same time; (3) The gas production is controlled by the casing pressure. The high-pressure gas layer at the bottom produces gas, and the gas goes up through the casing. When the gas goes up to the bottom of the lowest oil layer, it is affected by the sealing rubber tube of the packer I and enters the gas channel I of the packer I. Then, it passes through the gas bridge channel II of the production device and enters the gas channel I of the packer II. Finally, it returns to the casing through the gas external connection channel I of the packer II and continues to go up. (4) Obtain the pressure and temperature of each production layer through the pressure gauge and thermometer of the oil layer installed in the production distributor; (5) When the pressure of a certain oil layer reaches the development requirement, the electronically controlled regulating valve is opened and the oil layer is produced by self-flowing according to the designed output. The produced liquid of the oil layer enters the middle channel II of the inner central pipe II through the production channel of the production device, is measured by the flow meter of the central pipe II, and then enters the oil pipe through the oil pipe short circuit and the central pipe of the packer II along the liquid channel to start self-flowing oil production; (6) When the oil layer does not reach the self-flowing condition, open the gas lift valve and the high pressure in the casing gas The fluid enters the oil pipe through the gas lift valve, playing the role of gas lift oil production; (7) When the conditions for gas lift production are not met, the electrically controlled gas lift valve and the electrically operated liquid production valve are closed, and the oil layer enters the shutdown and pressure stabilization stage.

[0015] The invention provides an electrically controlled pipe string and production method for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs. By using an electrically controlled simultaneous production packer, an electrically controlled simultaneous production distributor and an electrically controlled gas lift valve, the invention realizes the production of oil and gas in separate flow channels in multi-lithologic oil reservoirs. Simultaneous production solves the problem of high-pressure gas layers affecting the liquid production of low-pressure oil layers, cleverly utilizes high-pressure gas to realize gas lift production of oil layers, increases oil layer production, and realizes flexible and controllable simultaneous and separate production in multi-lithologic oil reservoir production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 Schematic diagram of the multi-layer mining string structure. DETAILED DESCRIPTION

[0017] Example 1 The present invention provides an electrically controlled string for simultaneous oil and gas production in a multi-lithologic oil and gas reservoir, comprising a casing 1 and an oil pipe. A packer I2, a production distributor 3 and a packer II4 are sequentially arranged in the casing 1 from bottom to top. The packer I2, the production distributor 3 and the packer II4 are all tubular structures, and their intermediate channels are liquid flow channels; the packer I2, the production distributor 3 and the packer II4 are sequentially connected by a connecting pipe 5; the intermediate channels of the packer I2, the production distributor 3 and the packer II4 are connected to form a liquid channel, and gas channels are provided on the walls of the packer I2, the production distributor 3 and the packer II4 and are connected.

[0018] Example 2 like Figure 1 As shown, the present invention is an electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs, comprising a casing 1 and an oil pipe, wherein the oil pipe is used for oil production and the casing is used for gas production. A packer I2, a production distributor 3 and a packer II4 are sequentially arranged in the casing 1 from bottom to top. The packer I2 and the packer II4 have the same structure, but are installed in different directions when in use.

[0019] The production distributor 3 is composed of a central tube II 6, and an upper joint 7 and a lower joint 8 integrally formed at both ends thereof. The outer diameters of the upper joint 7 and the lower joint 8 are smaller than the outer diameter of the central tube II 6, and the inner diameters are larger than the inner diameter of the central tube II 6. An axial gas bridge channel II 9 is provided within the tube wall of the central tube II 6. The gas inlet and gas outlet at both ends of the gas bridge channel II 9 penetrate the tube wall and communicate with the lower joint 8 and the upper joint 7, respectively. A radial liquid production channel 10 is provided on the central tube II 6 and communicates with the intermediate channel II 26 of the central tube II 6. An electrically controlled regulating switch valve 11 is provided within the liquid production channel 10, and a flow meter 12 is provided within the intermediate channel II 26 above the liquid production channel 10.

[0020] In order to obtain the pressure and temperature of the oil layer, an installation groove is opened on the upper pipe wall of the production distributor 3. A thermometer 13 and a pressure gauge 27 are installed in the installation groove. By monitoring the pressure and temperature, the oil layer production valve is opened and adjusted.

[0021] The packer Ⅰ2 and the packer Ⅱ4 have the same structure, and are both composed of a center pipe Ⅰ14, and joints Ⅰ15 and Ⅱ16 integrated with its two ends. The outer diameter of the joint Ⅰ15 and the joint Ⅱ16 is smaller than the outer diameter of the center pipe Ⅰ14, and the inner diameter is larger than the inner diameter of the center pipe Ⅰ14. The center pipe Ⅰ14 contains an intermediate channel Ⅰ25, and an axial gas channel Ⅰ17 is provided in the wall of the center pipe 14. A rubber sleeve 18 is sleeved on the center pipe Ⅰ14. On one side of the rubber sleeve 18, the center pipe Ⅰ14 is provided with more than two radial gas external connection channels Ⅰ19 and is connected to the gas channel Ⅰ17. On the other side of the rubber sleeve 18, the center pipe Ⅰ14 is provided with an electric-controlled sealing mechanism 20 to drive the rubber sleeve 18 to expand and contract. The electric-controlled sealing mechanism is an existing technology and is widely used in oil field production. In this technical solution, the gas channel I17 is connected to the joint II16 near the electric control setting mechanism 20, and the gas channel I17 near the gas external connection channel I19 is not connected to the joint I15, forming a seal.

[0022] The aforementioned packer Ⅰ2 and packer Ⅱ4 can also be coaxially fixedly installed with two outer center tubes 28 and an inner center tube 29. A shoulder is provided at one end of the outer center tube 28, and one end of the inner center tube 29 sits on the shoulder and is sealed and fixed. The annular gap therebetween is the gas channel Ⅰ17, and the other end of the inner center tube 29 is placed at the opening of the outer center tube 28 to form the gas channel inlet and outlet.

[0023] The electrically controlled setting mechanism 20 and the electrically controlled regulating switch valve 11 both enter from the casing and are connected to the surface equipment.

[0024] When the oil and gas production electric control string in this technical solution is used, the joints II16 on the packer I2 and the packer II4 that are connected to the gas channel I17 are installed relative to each other, that is, the joint II16 of the packer 2 faces upward and the joint II16 of the packer II4 faces downward, and the production distributor 3 is installed in the middle. The joints of the packer I2, the production distributor 3 and the packer II4 are threadedly connected in sequence through the connecting pipe 5. At the same time, the intermediate channels of the packer I2, the production distributor 3 and the packer II4 are connected in sequence through the oil pipe short-circuit 24, and sealing rings are provided at the connections.

[0025] The joint I15 of the packer I2 is provided with a screw plug 21 to block it and prevent gas from entering the intermediate liquid flow channel. The joint I15 of the packer II4 is connected to the oil pipe 22, and the oil pipe 22 is connected to the electric-controlled gas lift valve 23. When the oil layer does not reach the self-flowing condition, the gas lift valve 23 is opened, and the high-pressure gas in the casing enters the oil pipe through the gas lift valve 23, which plays the role of gas lift oil production.

[0026] Example 3 The production method of an electrically controlled string for simultaneous oil and gas production in a multi-lithologic oil and gas reservoir as described in Example 2 comprises the following steps: (1) Connect the packer I2, the production device 3, the packer II4 and the gas lift valve 23 in sequence, lower the packer I2 to below the bottom of the low-pressure oil layer, lower the production device 3 to the middle of the low-pressure oil layer, and lower the packer II4 to above the top of the low-pressure oil layer; the installation directions of the packers I2 and II4 are different, such as Figure 1 As shown; (2) Power is turned on, and the surface operating system gives a setting signal. The signal is transmitted along the cable to the electric control setting mechanism 20 to control the setting of the rubber sleeve 18 of the packer I2, so that the rubber sleeve and the casing are sealed and the gas does not rise from the casing. Similarly, the packer II4 is also set at the same time. (3) The gas production is controlled by the casing pressure. The high-pressure gas layer at the bottom produces gas, and the gas goes up through the casing. When the gas goes up to the bottom of the lowest oil layer, it is affected by the sealing rubber tube 18 of the packer I2, and the gas enters the gas channel I17 of the packer I2 through the gas external connection channel I19, and then passes through the gas bridge channel II9 of the production device 3, and enters the gas channel I17 of the packer II4. Finally, it returns to the casing through the gas external connection channel I19 of the packer II4 and continues to go up. (4) Obtain the pressure and temperature of each production layer through the oil layer pressure gauge 27 and thermometer 13 installed in the production distributor 3; (5) When the pressure of a certain oil layer reaches the development requirement, the electronically controlled regulating switch valve 11 is opened, and the oil layer is produced by self-flowing according to the designed production rate. The oil produced by the oil layer enters the middle channel Ⅱ26 of the inner central pipe Ⅱ6 through the production channel 10 of the production distributor 3, is measured by the flow meter 13 of the central pipe Ⅱ6, and then passes through the oil pipe short circuit 24 and the central pipe 25 of the packer Ⅱ4 along the liquid channel to enter the oil pipe 22 for self-flowing oil production; (6) When the oil layer does not reach the self-flowing condition, the gas lift valve 23 is opened, and the high-pressure gas in the casing enters the oil pipe through the gas lift valve 23, playing the role of gas lift oil production; (7) When the conditions for gas lift production are not met, the electrically controlled gas lift valve and the electrically operated liquid production valve are closed, and the oil layer enters the shutdown and pressure stabilization stage.

[0027] When there are multiple low-pressure oil layers above the high-pressure gas layer, the second or third oil layer can be produced as needed; each oil layer can be produced separately or in combination, such as Figure 2 As shown, at this time, it is only necessary to install the packer I 2, the production device 3, and the packer II 4 in the casing corresponding to each low-pressure oil layer.

[0028] When the oil well needs minor repairs or other operations, the packers I2 and II4 can be unsealed.

Claims

1. An electric control string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs, comprising a casing (1) and an oil pipe, characterized in that The casing (1) is provided with a packer I (2), a production distributor (3) and a packer II (4) in sequence from bottom to top. The packer I (2), the production distributor (3) and the packer II (4) are all tubular structures, and the middle passages thereof are liquid flow passages; the packer I (2), the production distributor (3) and the packer II (4) are connected in sequence through a connecting pipe (5); the middle passages of the packer I (2), the production distributor (3) and the packer II (4) are connected to form a liquid passage, and the walls of the packer I (2), the production distributor (3) and the packer II (4) are all provided with gas passages and are connected.

2. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 1, characterized in that The production distributor (3) is composed of a central tube II (6), and an upper joint (7) and a lower joint (8) integral with its two ends. An axial gas bridge channel II (9) is provided in the tube wall of the central tube II (6), and a radial liquid production channel (10) is provided on the central tube II (6) and communicated with the middle channel II (26) of the central tube II (6).

3. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 2, characterized in that The gas inlet and gas outlet at both ends of the gas bridge channel II (9) are communicated with the lower joint (8) and the upper joint (7) respectively.

4. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 2, characterized in that An electrically controlled regulating switch valve (11) is provided in the liquid production channel (10).

5. The electric control string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs as claimed in claim 2, characterized in that A flow meter (12) is provided on the middle channel II (26) of the central tube II (6).

6. The electric control string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs as claimed in claim 2, characterized in that An installation groove is provided on the upper tube wall of the production dispenser (3), and a thermometer (13) and a pressure gauge (27) are provided in the installation groove.

7. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 1 or 2, characterized in that The packer I (2) and the packer II (4) have the same structure, and are both composed of a central tube I (14), and joints I (15) and II (16) integrally formed with the two ends thereof. The central tube I (14) contains an intermediate channel I (25), an axial gas channel I (17) is provided in the wall of the central tube (14), a rubber sleeve (18) is sleeved on the central tube I (14), and more than two radial gas external connection channels I (19) are provided on the central tube I (14) on one side of the rubber sleeve (18) and are connected to the gas channel I (17). The other side of the rubber sleeve (18) is provided with an electric-controlled sealing mechanism (20) to drive the rubber sleeve (18) to expand and contract.

8. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 7, characterized in that The gas passage I (17) on one side of the electric-controlled setting mechanism (20) is communicated with the connector II (16).

9. The electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 8, characterized in that The joint I (15) of the packer I (2) is provided with a screw plug (21) to seal it, the joint II (16) is connected to the lower joint (8) of the production distributor (3) through a connecting pipe (5), the upper joint (7) of the production distributor (3) is connected to the joint II (16) of the packer II (4) through a connecting pipe (5), the joint I (15) of the packer II (4) is connected to the oil pipe (22), and the electric control gas lift valve (23) is connected to the oil pipe (22); the intermediate channel I (25) and the intermediate channel II (26) of the packer I (2), the production distributor (3) and the packer II (4) are sequentially connected through the oil pipe short circuit (24).

10. A production method using an electrically controlled string for simultaneous oil and gas production in multi-lithologic oil and gas reservoirs according to claim 1, characterized in that The steps include: (1) Connect the packer I (2), the production device (3), the packer II (4) and the gas lift valve (23) in sequence, lower the packer I (2) to below the bottom of the low-pressure oil layer, lower the production device (3) to the middle of the low-pressure oil layer, and lower the packer II (4) to above the top of the low-pressure oil layer; (2) Power is turned on, and the electrically controlled setting mechanism (20) controls the rubber sleeve (18) of the packer I (2) to set, so that the rubber sleeve and the casing are sealed and the gas does not rise from the casing; similarly, the packer II (4) is also set at the same time; (3) The gas production is controlled by the casing pressure. The high-pressure gas layer at the bottom produces gas, and the gas moves upward through the casing. When the gas moves upward to the bottom of the lowest oil layer, it is affected by the sealing rubber tube of the packer I (2) and enters the gas channel I (17) of the packer I (2). Then, it passes through the gas bridge channel II (9) of the production distributor (3) and enters the gas channel I (17) of the packer II (4). Finally, it returns to the casing through the gas external connection channel I (19) of the packer II (4) and continues to move upward. (4) Obtaining the pressure and temperature of each production layer through the oil layer pressure gauge (27) and thermometer (13) installed in the production distributor (3); (5) When the pressure of a certain oil layer reaches the development requirement, the electronically controlled regulating switch valve (11) is opened, and the oil layer is produced by self-flowing according to the designed production rate. The oil produced by the oil layer enters the middle channel II (26) of the inner central pipe II (6) through the production channel (10) of the production distributor (3), is measured by the flow meter (13) of the central pipe II (6), and then enters the oil pipe (22) along the liquid channel through the oil pipe short circuit (24) and the central pipe (25) of the packer II (4) to carry out self-flowing oil production; (6) When the oil layer does not reach the self-flowing condition, open the gas lift valve (23) and the high pressure in the casing gas The fluid enters the oil pipe through the gas lift valve (23), playing the role of gas lift oil production; (7) When the conditions for gas lift production are not met, the electrically controlled gas lift valve and the electrically operated liquid production valve are closed, and the oil layer enters the shutdown and pressure stabilization stage.

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