CN204591237U - Oil well multiple-zone production down-hole automatic layer-changing device - Google Patents

Abstract

The utility model relates to field of petroleum exploitation, particularly a kind of oil well multiple-zone production down-hole automatic layer-changing device.The utility model is separated using pressure as controling parameter and is controlled the current intelligence of the oil of adjacent two layers, it is characterized in that: be made up of outer screen, inner screen, balancing spring, locking device, spool, axle sleeve, constrictor, spring-loaded plunger, spring, cavity and plunger etc., inner screen and outer screen composition concentric screen, being open mode when inner screen is positioned at lower gear, is closed condition when being positioned at gear.The utility model its install quantity and position can with the quantity of oil reservoir and position corresponding, and unrestricted, the Automated condtrol without the need to artificially manipulating can be realized, expand oil recovery flow, reduce oil recovery energy consumption, there is structure simple, dependable performance, the advantages such as Be very effective.

Description

Downhole automatic layer changer for oil well multi-layer production

technical field

The utility model relates to the field of oil exploitation, in particular to an automatic layer changing device for underground multi-layer exploitation of oil wells.

Background technique

Cross-reservoir joint production of oil wells is a common method used in most oilfields at present. However, due to the differences in the pressure, permeability, oil properties and water content of each oil layer, the oil layers interfere with each other and complicate the production of oil wells. In the prior art, the Chinese patent application (publication number CN1389639A, published on January 8, 2003) "Downhole pipe string and its implementation process for oil production by changing layers without moving pipe strings" discloses a downhole pipe string that can realize oil recovery by changing layers. The pipe string and its implementation process are mainly to open or close the layer change switch by pressurizing the casing annular space on the ground. The disadvantages are: 1. It is necessary to use the surface pump unit to raise the annular pressure The workload is heavy, the cost is high, and the requirements for tubing and casing are very high. 2. Since the reservoir pressure fluctuates, it is difficult to determine the final pressure value in the annular space. 3. This pipe string can only achieve two layers of oil layers, and it is not suitable for multiple oil layers. In the Chinese patent application (authorized announcement number CN2761835, authorized announcement date March 1, 2006) "management and control of hydraulic layer change switch", ground pump truck must be used to pressurize the oil sleeve annulus to realize the layer change function, and the workload is the same. very big.

Contents of the invention

The purpose of the utility model is to provide a simple structure and reliable downhole automatic layer changer for oil well multi-layer production, so as to overcome the shortcomings of the current layered oil production technology. The automatic layer changer relies on the difference in oil pressure of each oil layer to realize the automatic layer change process of downhole multi-layer oil recovery.

The technical scheme of the utility model is: an automatic layer changer for multi-layer production of an oil well, the layer changer is placed on the fixed pipe string at the same depth as the casing perforation, and the pressure is used as a control parameter to separate and control phase The circulation of the oil adjacent to the two layers is characterized in that: the outer screen, the inner screen, the balance spring, the locking device, the valve core, the bushing, the restrictor, the spring plunger, the spring, the cavity and the Composed of plungers, the inner screen and the outer screen form a double-layer screen. When the inner screen is in the lower gear, it is in the open state, and when it is in the upper gear, it is in the closed state.

The locking device is located between the outer screen tube and the shaft sleeve, and is composed of two spring plungers distributed symmetrically along the radial direction of the oil pipe, with the head pointing to the axis. The spring plunger is composed of a spring, a plunger and a cavity, and is locked The device cooperates with the limit ring on the upper part of the spool to lock the spool at the gear position.

The balance spring is located between the top of the spool and the locking device, and its model can be selected according to specific production needs; the shaft sleeve is located at the lower part of the locking device, and there are four symmetrically distributed circular through-holes above it.

The spool is located in the shaft sleeve, and its interior is hollow. The lower part is provided with 2 rows of 8 symmetrically distributed circular through-holes, through which the oil in the lower oil layer can flow in; There is a limit ring on the upper end of the spool to limit the stroke of the spool and make the spool have fixed upper and lower gears. The spool is rigidly connected to the inner screen, and its movement can drive the movement of the inner screen.

The restrictor is located at the bottom of the layer changer, and cooperates with the valve core as the lower oil valve switch.

Compared with the prior art, the utility model has the following effects:

Realized the function of automatic layer-changing production in multi-reservoir production, solved the problem of mutual interference between oil layers caused by different pressure and productivity rules of different oil layers, and the problem that the production and water content of each layer cannot be distinguished and measured during joint production of oil layers.

The pressure is used as the control parameter to carry out layer-changing mining to realize automatic control without human manipulation.

Two types of valves were designed and combined to realize the unification of oil passages for different layers of reservoirs, so as to maximize the oil production flow.

A locking device and a spring plunger are used to make the reversing process only after the pressure difference on both sides increases to a value higher than the preset value, which also makes the reversing process of the spool more rapid and effectively prevents the spool from being out of balance. location stay.

The balanced spring is used to balance the weight of the valve core and the inner screen pipe, and through the design of the spring stiffness coefficient, the targeted layer-changing mining of a certain layer is realized.

The movement of the spool under pressure is used to realize the function of automatically exploiting high-pressure oil reservoirs, effectively utilizing the natural energy of formation pressure, and reducing the energy consumption of oil extraction.

Description of drawings

Fig. 1 is a longitudinal sectional view of the structural principle of the present utility model.

Figure 2 is a schematic diagram of the locking device.

Figure 3 is a schematic diagram of the spring plunger.

Fig. 4 is an overall longitudinal sectional view of the first embodiment of the layer changer.

Fig. 5 is a cross-sectional view of the double-layer screen of the first embodiment of the layer changer.

Fig. 6 is an overall longitudinal sectional view of the second embodiment of the layer changer.

Fig. 7 is a cross-sectional view of the double-layer screen of the second embodiment of the layer changer.

Fig. 8 is a diagram of the installation position of the utility model.

In Fig. 1, 1. Outer screen, 2. Inner screen, 3. Balance spring, 4. Locking device, 5. Valve core, 6. Shaft sleeve, 7. Restrictor, 8. Oil pipe, 9 . Casing after perforation.

Figure 2, 10. Spring plunger.

Among Fig. 3, 11. spring, 12. cavity, 13. plunger.

In Fig. 8, 14. immobile string, 15. packer, 16. layer changer, 17. screen.

Detailed ways

The utility model will be further described below in conjunction with accompanying drawing:

See Figure 1, the downhole automatic layer changer for oil well multi-layer production, from top to bottom consists of outer screen (1), inner screen (2), balance spring (3), locking device (4), valve core (5), axle sleeve (6) and restrictor sheet (7) form. The position of the layer changer in the fixed pipe string (8) is shown in Figure 1. The upper and lower sides of the layer changer are fixed pipe strings (8), and are lowered into the well simultaneously with two sections of fixed pipe strings (8) to reach the designated position. As shown in Fig. 8, the fixed string (14) is fixed on the casing (9) through the packer (15), the bottom of the fixed string is a screen (17) or a one-way valve, and the layer changer ( 16) Installed between two adjacent packers, the number and positions of which can be installed correspond to the number and positions of oil layers, and are not limited.

The locking device (4) shown in Figure 2 contains two symmetrically distributed spring plungers (10) inside, and the spring plunger (10) is composed of a spring (11), a cavity (12) and a plunger (13). ), different types of spring plungers (10) can be used, so that the layer changing process can be carried out after the pressure difference on both sides of the spool (5) is higher than a certain value.

According to different production environments, different types of balance springs (3) can be used to achieve targeted exploitation of a certain layer: the larger the stiffness coefficient of the balance spring (3), the easier it is to exploit the upper oil layer, and the smaller the stiffness coefficient is, the easier it is to exploit the oil layer. It is easy to exploit the lower oil layer.

In the first embodiment shown in Figure 4, the spool (5) of the layer changer and the inner screen (2) are in the lower position, the middle of the spool (5) is locked by the locking device (4), and the spool (5) The bottom end blocks the flow-limiting hole of the flow-limiting plate (7), and the oil in the lower oil layer cannot continue to pass through the layer changer upwards. As shown in Figure 5, the inner layer screen (2) is in the lower position, and the double-layer screen is in an open state, so that oil in the upper oil layer can pass through the double-layer screen and enter the oil pipe. In this embodiment, only the upper oil layer is produced, and its pressure is continuously reduced, and the lower oil layer is in a pressure recovery state, and its pressure is continuously increased. When the difference between the pressure of the oil in the upper oil layer acting on the upper part of the spool (5) and the supporting force of the oil in the lower oil layer acting on the bottom of the spool (5) is greater than the set value, the spool (5) will break away from the locking device ( 4) the shackles move downward and are re-locked by the locking device (4) to reach the lower gear, and complete the process of automatic layer-changing mining.

In the second embodiment shown in Figure 6, the spool (5) of the layer changer and the inner screen (2) are in the upper position, the middle of the spool (5) is locked by the locking device (4), and the spool (5) There is a certain distance between the bottom end and the flow-limiting hole of the flow-limiting sheet (7), and the oil in the lower oil layer can upwardly pass through the layer changer from the flow-limiting hole. As shown in Figure 7, the inner layer screen (2) is in the upper position, the double-layer screen is in a closed state, and the oil in the upper oil layer cannot enter the oil pipe from the double-layer screen. In this embodiment, only the lower oil layer is produced, and its pressure is continuously reduced, and the upper oil layer is in a pressure recovery state, and its pressure is continuously increased. When the difference between the support force of oil in the lower oil layer acting on the bottom of the spool (5) and the pressure of oil in the upper oil layer acting on the upper part of the spool (5) is higher than the set value, the spool (5) will break away from the locking device ( 4) the shackles move upwards and are locked by the locking device (4) again to reach the upper gear, and complete the process of automatic layer-changing mining.

Claims (5)

1. The downhole automatic layer changer for oil well multi-layer production is characterized in that it consists of an outer layer screen (1), an inner layer screen (2), a balance spring (3), a locking device (4), a valve core (5 ), bushing (6), restrictor (7), spring plunger (10), spring (11), cavity (12) and plunger (13), the inner screen (2) and the outer The screen pipe (1) forms a double-layer screen pipe, and when the inner screen pipe (2) is in the lower gear, it is in an open state, and when it is in the upper gear, it is in a closed state. 2. The downhole automatic layer changer for oil well multi-layer production according to claim 1, characterized in that: the locking device (4) is located between the outer screen (1) and the bushing (6), and consists of two Oil pipes are radially symmetrically distributed, and the head is directed to the axis of the spring plunger (10). The spring plunger (10) is composed of a spring (11), a plunger (13) and a cavity (12). The locking device (4 ) cooperates with the limit ring on the top of the spool (5), so that the spool (5) can be locked at the gear position. 3. The downhole automatic layer changer for oil well multi-layer production according to claim 1, characterized in that: the balance spring (3) is located between the top of the valve core (5) and the locking device (4), and its model can be selected according to the specific Production needs to be selected; the shaft sleeve (6) is located at the bottom of the locking device (4), and its top is provided with 4 circular through holes that are symmetrically distributed. 4. The downhole automatic layer changer for oil well multi-layer production according to claim 1, characterized in that: the valve core (5) is located in the bushing (6), the inside of which is hollow, and the lower part is provided with 2 rows of 8 symmetrically distributed The circular through hole, the upper end of the spool (5) is provided with a limit ring, and the spool (5) is rigidly connected to the inner screen pipe (2). 5. The downhole automatic layer changer for multi-layer production of oil wells according to claim 1, characterized in that: the restrictor plate (7) is located at the bottom of the layer changer, and cooperates with the valve core (5) as a valve switch for lower layer oil.