RU2718553C1 - Pumping-ejector plant for downhole fluid transfer from lower to upper formation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to mining, in particular to oil industry, and can be used for pumping liquid into upper oil-bearing formation from lower formation of well, especially with high content of associated gas. Pumping-ejector plant for downhole transfer of liquid from lower to upper formation comprises downhole electrically driven centrifugal pump (EDCP) with power cable from control station, which are lowered to casing string on tubing string. Extracted liquid-jet ejector made with through sections of nozzle and mixing chamber, directly proportional to flow rate of lower formation. Lower pulse-mechanical packer separating formations in casing string of well. Upper packer with pressing hydraulic anchor with thrust against lower packer. Ejector inlet nozzle is connected to outlet EDCP branch pipe, and diffuser – with bottom packer barrel and installed channels supplying associated gas at level of upper boundary of under-packer cavity. Upper packer is installed above the upper formation of the well and forms an inter-packer cavity communicating with the upper formation with the lower packer. A filter is mounted in the tubing string at the level of the upper bed, above which a plug is installed in the tubing string excluding release of formation fluid to the surface of the well.

EFFECT: improving operating reliability of centrifugal pump of the plant at downhole transfer of liquid into upper formation from lower formation, especially with high content of associated gas.

6 cl, 1 dwg

Description

The invention relates to the field of mining, in particular to the oil industry, and can be used to pump fluid into the upper oil reservoir from the lower reservoir, especially with a high content of associated gas.

A known installation for pumping fluid from the lower layer into the upper layer of the well, having the ability to seal the wellhead and containing a packer, lowered into the well on a pipe string in which radial channels are made, and at the end of the pipe string, a suction valve is installed that divides the annulus into two parts above and below the packer, an electric submersible pump, forming in the pipe string an upper cavity communicating with the upper layer through radial channels, and a lower cavity communicating with the lower layer through the suction to apan, wherein the fluid pressure sensor is mounted with the possibility of turning on and off electric submersible pump. (Patent RU No. 2278671 C1. Installation for pumping fluid from the lower reservoir into the upper reservoir of the well. - IPC: Е21В 43/14. - 20.11.2006).

There are two installation options for downhole pumping of water from the lower to the upper layers, which contain a column of lift pipes, a packer, an electric submersible pump with an electric motor, a cable and a casing enclosing the electric motor, equipped with a cable sealing unit that is located in the pump input module and communicates with the under-packer space through the shank. According to the first embodiment, a check valve is installed at the outlet of the electric submersible pump, through which the pump communicates with the column of elevator pipes made with an opening for supplying water to the annulus and the upper formation. A flow meter is installed between the hole in the elevator pipe and the pump outlet. According to the second embodiment, an additional column of elevator pipes is placed inside the column of elevator pipes, coupled by a two-channel coupling with a seat made with a nipple of a movable connection for supplying water to the annulus and the upper layer. (Patent RU No. 2351749 C1. Installation for downhole pumping of water from the lower reservoir in the upper (options). - IPC: Е21В 43/14. - 04/10/2009).

A known installation for pumping fluid into the upper layer of the well from the bottom, containing a packer installed between the layers, an electric submersible pump with an electric drive and an input module, with a cable passing through the cable sealing assembly of the input module, and a check valve at the outlet for communication with the lift pipe string and downhole space, a casing made with the coverage of the electric submersible pump, hermetically connected to the input module of the electric submersible pump, communicating with the under-packer space through the shank, and flow meter. Above the injection valve, an additional packer with a cable sealing unit located above the upper layer is placed on the elevator string. A hydraulic compensator is located between the pump and the electric drive. The column of elevator pipes communicated with the downhole space through the injection valve, passing from the inside out. The electric drive below is equipped with a measuring unit, configured to transmit information through the cable of the electric submersible pump, the measuring unit is equipped with a damping sleeve for centering and damping vibrations in the casing. (Patent RU No. 2436939 C1 for the invention. Installation for pumping fluid into the upper wellbore from the lower one. - IPC: ЕВВ 43/14. - 12/20/2011).

A well-known installation for pumping fluid from the lower to the upper layers of the well, containing lift pipes connected by a packer separating the interstratal space, an electric submersible pump including an electric drive equipped with a telemetry unit, hermetically connected by a power cable to the control station, a receiving module and working sections with a check valve on output, and reference packer with cable entry above the oil reservoir. The pump is located by a telemetry unit above the flooded wellbore and a non-return valve is connected by lift pipes to the trunk of the interstratal packer, made with a cable entry and a reference armature. The interpacker lift pipes at the level of the oil reservoir are connected by a borehole flow chamber, in the wall of which radial flow holes are made, communicating the cavity of the elevator pipe with the oil reservoir through the interpacker space of the well. (Patent RU No. 2591061 C2. Installation for pumping fluid from the lower to the upper layers of the well. - IPC: Е21В 43/14, F04B 47/06. - 07/10/2016).

Known pump-ejector installation containing lowered into the well at the tubing of an electric drive centrifugal pump and a liquid jet ejector, interconnected by a pipe. A gas separator is installed at the inlet of the centrifugal pump, and a non-return valve is installed in the channel for supplying the pumped medium from the annulus of the well to the receiving chamber of the ejector. At the outlet of the centrifugal pump, a receiver with a check valve is installed. The liquid-jet ejector is made with flow sections of the nozzle and mixing chamber, directly proportional to the flow rate and volume of gas and inversely proportional to the depth of the dynamic level of the well fluid. A centrifugal pump is selected with a pressure from the condition of the pressure distribution to lift the masses of gas-liquid mixture along the tubing string and the separated liquid through the pipe between the centrifugal pump and the liquid jet ejector and to operate the liquid jet ejector. A packer can be installed on the tubing string with a cable entry above the channel for supplying the pumped medium from the annulus of the well to the receiving chamber of the liquid jet ejector. (Patent RU No. 2553110 C2. Method for the production of a single-layer borehole fluid and a pump-ejector installation for its implementation. - IPC: Е21В 43/12, F04F 5/54. - 10.06.2015).

The closest analogue adopted for the prototype is a pump-ejector unit for oil production from two layers of one well, containing an electric drive centrifugal pump with a power cable being lowered into a well on a tubing string, a liquid jet ejector connected to the pipe inlet to the nozzle which is equipped with a check valve, and at least one packer with cable entry, separating the wellbore. A receiver is installed at the outlet of the centrifugal pump, connected by a pipe to the inlet of the liquid jet ejector, the aforementioned check valve is installed at the outlet of the receiver, and a second non-return valve is installed in the channel for supplying fluid from the upper formation to the receiving chamber of the ejector, while the liquid jet ejector is made with sections of the nozzle and mixing chamber are directly proportional to the flow rate of the lower layer and the flow rate of both layers of the well, respectively. An additional packer can be installed on the tubing string with cable entry at a level higher than the oil supply channel from the upper wellbore to the receiving chamber of the liquid ejector. (Patent RU No. 2550613 C2. A method for producing fluid from two layers of one well and a pump-ejector installation for its implementation. - IPC: Е21В 43/14, Е21В 43/12. - 05/10/2015).

A disadvantage of the known installations is the formation of a gas cap from the associated gas in the sub-packer cavity, which accumulates as oil is produced and reduces the dynamic level of the reservoir fluid in the bottom of the well, exposing the centrifugal pump, which leads to the shutdown of the installation, thereby reducing the operational efficiency of the installation and the service life of the centrifugal pump.

The main task to be solved by the claimed invention is aimed at eliminating the formation of a gas cap in the sub-packer cavity, which causes the centrifugal pump of the installation to malfunction by suctioning the associated gas from the sub-packer cavity directly into the tubing string during downhole pumping of liquid from the lower to the upper layer wells.

The technical result is to increase the reliability of the centrifugal pump of the installation during downhole pumping of liquid into the upper layer from the lower layer, especially with a high content of associated gas.

The specified technical result is achieved by the fact that, in the known pump-ejector installation for downhole fluid pumping from the lower to the upper formation, containing electric drive centrifugal pump with a power supply cable from the control station, a liquid ejector, made with flow sections of the nozzle and mixing chamber, directly proportional to the flow rate of the lower layer, and packers with cable entry, one of which divides the layers into bsadnoy column wells, according to the proposed technical solution,

the liquid-jet ejector is connected by the nozzle inlet to the outlet of the centrifugal pump, and the diffuser is connected to the lower packer barrel separating the strata in the well casing, and the accompanying gas supply channels are installed at the level of the upper boundary of the sub-packer cavity, while the upper packer is installed above the upper stratum and forms with the lower packer, an interpacker cavity communicating with the upper wellbore, and a filter is mounted in the tubing string at the level of the upper reservoir, above which the column is installed a stub has been plugged in, eliminating the release of formation fluid to the surface of the well and creating additional pressure of the gas-liquid mixture in the upper formation;

in the tubing string between the lower packer and the filter, an emergency disconnector of the string and power cable is integrated;

the lower packer is made of pulse-mechanical;

the upper packer is made with a hydraulic pressure anchor with emphasis in the lower packer;

electric centrifugal pump is frequency-adjustable;

electric centrifugal pump is equipped with a telemetry unit.

The analysis of the prior art cited by the applicant made it possible to establish that there are no analogs characterized by sets of features identical to all the features of the claimed pump-ejector installation for downhole pumping of fluid from the lower to the upper reservoir. Therefore, the claimed technical solution meets the condition of patentability "novelty."

The search results for known solutions in the art in order to identify features that match the distinctive features of the prototype of the features of the claimed technical solution have shown that they do not follow explicitly from the prior art. From the prior art determined by the applicant, the influence of the transformation provided for by the essential features of the claimed technical solution on the achievement of the specified technical result is not revealed. Therefore, the claimed technical solution meets the condition of patentability "inventive step".

The claimed technical solution is tested and implemented in oil wells. Therefore, the inventive pump-ejector installation for downhole pumping of fluid from the lower to the upper reservoir meets the condition of patentability "industrial applicability".

In FIG. 1 schematically shows a pump-ejector installation for downhole fluid pumping from the lower to the upper reservoir.

The pump-ejector installation for downhole fluid pumping from the lower to the upper reservoir contains wells lowered into the casing string on a tubing string (1 tubing) 1 submersible electric drive centrifugal pump (ESP) 2 with a power cable 3 to the power supply from the control station 4, a removable liquid-jet ejector 5, made with the passage sections of the nozzle 6 and the mixing chamber 7, directly proportional to the flow rate of the lower formation I, the lower pulse-mechanical packer 8, disconnecting the lower I and upper II layers in the casing it is not a well, and the upper packer 9 with a hydraulic pressure armature 10 with an emphasis on the lower packer 8. The electric drive 11 of the ESP 2 is frequency-controlled and equipped with a telemetry unit 12. The ejector 5 is connected to the outlet of the ESP 2 with the outlet of the ESP 2 by a pipe 13, and a diffuser 14 - with the trunk of the lower packer 8, and is arranged with channels 15 for supplying concomitant gas, bleed from the under-packer cavity 16 to the receiving chamber 17 at the level of the upper boundary of the under-packer cavity 16. The upper packer 9 is installed above the upper formation II and forms an inter-packer cavity 18 with the lower packer 8 communicating with the upper layer II. A filter 19 is mounted in the tubing string 1 at the level of the upper formation II of the well above which a plug 20 is installed in the tubing string 1, eliminating the release of formation fluid to the surface of the well and increasing the working pressure of the well fluid in the upper formation II and a hydraulic armature 10 to secure the packer 9. The installation was made with the possibility of mounting and dismounting it in two steps, for which an emergency disconnector 21 of the tubing string 1 and power cable 3 is integrated in the tubing string 1 between the filter 19 and the lower packer 8.

Pump-ejector installation for downhole fluid pumping from the lower to the upper reservoir works as follows.

After installing the pump-ejector installation for downhole fluid pumping from the lower to the upper layer in the wellbore by connecting its lower and upper parts with an emergency disconnector 21 of the tubing 1 and power cable 3, from the control station 4 they turn on the work of the submersible ESP 2, supplying power to the electric drive 11 of the ESP 2 along the power cable 3. The submersible ESP 2 starts to extract fluid from the lower reservoir I and pumps with pressure through the nozzle 13 to the inlet to the nozzle 6, then to the receiving chamber 17 of the liquid-jet ejector 5. Part is concomitant gas from the lower reservoir I flows into the under-packer cavity 16, from the upper part of which the associated gas is discharged through the channels 15 into the receiving chamber 17 of the liquid-jet ejector 5, thereby eliminating the formation of a gas cap in the under-packer cavity 16. Under the pressure of the jet of fluid created by the nozzle 6, the bleed associated gas enters the mixing chamber 7 at the same time as the fluid from the under-packer cavity 16 from the receiving chamber 17. Then, the diffuser 14 of the liquid-jet ejector 5 moves the gas-liquid mixture along the tubing string 1 into the filter 19, from which the gas-liquid mixture is pumped through the interpacker cavity 18 to the upper layer of the II well. A plug 20 installed in the tubing string 1 eliminates the release of formation fluid on the surface of the well and increases the working fluid pressure in the tubing string 1, which acts on the hydraulic armature 10 with an emphasis in the lower packer 8, reinforcing the fixing of the upper packer 9 in the well casing. The downhole pumping of the gas-air mixture from the lower I to the upper II layer is carried out under the control of the telemetry unit 12 ESP 2, which responds to pressure corresponding to the liquid level in the sub-packer cavity 16, which communicates with the formation I. According to the reaction of the telemetry unit 12, the signal is transmitted via a power cable 3 to the control station 4, the latter, if necessary, changes the frequency of rotation of the drive shaft of the frequency-controlled electric drive 11 of the submersible ESP 2. During operation and in emergency situations, the dismantling of the installation olnyayut also parts severing the tubing 1 and the power cable 3 emergency disconnector 21.

The use of the proposed pump-ejector unit for downhole pumping of fluid from the lower to the upper reservoir will significantly increase the efficiency of wells in oil fields.

Claims (6)

1. Pump-ejector installation for downhole fluid pumping from the lower to the upper layer, containing electric wells, a centrifugal pump with a power supply cable from a control station, and a liquid-jet ejector made with passage sections of a nozzle and a mixing chamber , directly proportional to the flow rate of the lower formation, and packers with cable entry, one of which separates the formation in the casing of the well, characterized in that the liquid-jet the inlet to the nozzle is connected by a nozzle to the outlet of the centrifugal pump, and the diffuser is connected to the lower packer barrel separating the strata in the well casing and the accompanying gas supply channels are installed at the level of the upper boundary of the sub-packer cavity, while the upper packer is installed above the upper stratum and forms by the lower packer, an interpacker cavity communicating with the upper wellbore, and a filter is mounted in the tubing string at the level of the upper reservoir, above which a plug is installed in the string, eliminating the release of formation fluid to the surface of the well and creating additional pressure of the gas-liquid mixture into the upper formation. 2. Installation according to claim 1, characterized in that an emergency disconnector of the column and the power cable is built into the tubing string between the filter and the lower packer. 3. Installation according to claim 1, characterized in that the lower packer is made of pulse-mechanical. 4. Installation according to claim 1, characterized in that the upper packer is made with a hydraulic push arm with an emphasis in the lower packer. 5. Installation according to claim 1, characterized in that the electric drive of the centrifugal pump is frequency-adjustable. 6. Installation according to claim 1, characterized in that the electric centrifugal pump is equipped with a telemetry unit.

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