RU2553110C2 - Method of production of single-formation borehole fluid and pumping and ejecting unit for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes pumping-out of fluid by the centrifugal pump, at the beginning of which the fluid is subjected to separation and the emitted gas is sent to annular space, and the separated liquid is injected by the centrifugal pump in a laminar current into the nozzle of the liquid jet ejector installed on the tubing string above the dynamic level of the borehole fluid then simultaneously with the separated liquid by the ejector gas is sucked away from annular space into the tubing string. The fluid is produced by the centrifugal pump with the pressure head selected from the condition of distribution of pressure on lifting of mass of gas-liquid mix along the tubing string and the separated liquid along the pipe between the centrifugal pump and the ejector and on operation of the ejector taking into account the depth of dynamic level. Through passage sections of the nozzle and the chamber for mixing of the liquid jet ejector are set directly proportional to the output and volume of gas and inversely proportional to the depth of dynamic level of the borehole fluid. The pumping and ejecting unit for implementation of the named method is also described.

EFFECT: improvement of reliability of well operation.

3 cl, 2 dwg

Description

The group of inventions relates to the field of mining, in particular to oil production, and can be used to produce fluid, mainly with a high gas content, from a single-layer well.

There is a method of relieving excess gas pressure from the annular space of a well during operation by submersible electric pumps, which includes operating an oil well by an electric centrifugal pump and an associated jet pump, the latter being installed on tubing above a steady-state dynamic level, which, when the produced oil passes through it, pumps gas from annulus of the well (Patent RU No. 2081998 C1. Method for relieving excess gas pressure from the annulus of the well during operation by submersible electric pumps. - IPC: E21B 43/00. - 06/20/1997).

Known pump-ejector installation for oil production, including a sequentially located submersible electric motor, a centrifugal separator of mechanical impurities with a screw with a variable pitch in the form of a sleeve with blades, equipped with at least one pump stage installed at the inlet, a centrifugal pump and a jet pump, to the receiving chamber of which has a connecting pipe for pumping the separated particles from the separator (Patent RU No. 138787 U1. Submersible pumping and ejector unit for oil production. - IPC: F04D 13/08. - 20.03.2014).

Known jet borehole pump installation containing a tubing string with an upper packer installed on it above the upper layer, a lower packer between the upper and lower layers of the well and the jet pump, the nozzle of the latter from the input side is communicated with the pipe string below the jet pump and the outer side - with the upper layer. A centrifugal pump is attached to the lower end of the tubing string. The lower packer is located no more than 10 m below the sole of the upper layer, and the upper packer is no more than 10 m above its roof (Patent RU No. 2278996 C1. In-line well pumping unit. - IPC: F04F 5/54. - 20.03.2014).

A disadvantage of the known technical solutions is the occurrence of turbulence in the fluid stream at the outlet of the centrifugal pump, leading to foaming of the injected fluid and pressure fluctuations at the inlet to the nozzle of the jet pump, and, as a result, to shut down the installation.

The closest analogue of the claimed group of technical solutions is a method of oil production, including pumping products from the formation into the well, partial separation of free gas from the liquid and the flow of part of the free gas into the annulus, dispersing the gas-liquid mixture with the residual gas content, the subsequent flow of the gas-liquid mixture with the residual gas content in the pump and its injection into the nozzle of the jet apparatus by a jet, which is shaped to prevent sound locking of the nozzle, ejection with by a blasting apparatus of a part of a well’s production into tubing with a part of the free gas coming from the annulus and regulating the gas pressure in the annulus, and raising the gas-liquid mixture to the surface. A device for implementing the above method is known, comprising a pump and an inkjet apparatus provided with a diaphragm type nozzle lowered into a well on tubing. Above the inkjet apparatus, a bypass valve is installed on the tubing. A gas separator-disperser is installed at the pump inlet (Patent RU No. 2274731 C2. Method for oil production and a device for its implementation. - IPC: E21B 43/00, F04F 5/54. - 04/20/2006). These technical solutions are taken as prototypes.

A disadvantage of the known technical solutions adopted for the prototypes is the occurrence of turbulence in the fluid stream at the outlet of the centrifugal pump, leading to foaming of the injected fluid and pressure fluctuations at the inlet to the nozzle of the jet pump, and, as a result, to shutdown the installation, which reduces production efficiency and negatively affects the service life of the electric centrifugal pump.

The main task to be solved by the claimed invention is directed is to increase the efficiency of well operation by eliminating failures in the operation of a liquid ejector.

The technical result is to increase the efficiency of well operation by eliminating malfunctions in the operation of a liquid-jet ejector.

The specified technical result is achieved by the fact that, in the known method of producing a single-layer well fluid, including pumping the formation fluid with a centrifugal pump from the bottom of the wellhead, at the beginning of which the fluid is separated and the gas released is sent to the annulus, and the separated fluid is pumped by a centrifugal pump through the pipe into a liquid jet ejector nozzle, the latter being installed on the tubing string above the dynamic level of the borehole fluid, then the ejector simultaneously with gas is sucked from the annulus of the well into the tubing string by the separated liquid, according to the proposed technical solution, the separated liquid is pumped into the nozzle of the liquid jet ejector by a laminar flow, and the production of the well fluid is carried out by a centrifugal pump with a pressure specified from the distribution of pressure on the mass lift of the gas-liquid mixture along the tubing string and the separated fluid through the pipe between the centrifugal pump and the liquid jet ejector and a work fluid jet ejector with the depth of the borehole fluid dynamic level, while communicating the nozzle and the mixing chamber define fluid jet ejector is directly proportional to flow rate and volume of the gas and inversely proportional to the depth of the dynamic level of the well fluid.

The specified technical result is achieved by the fact that in the known pump-ejector installation for the production of a single-layer borehole fluid containing electric drive centrifugal pump and a liquid jet ejector that are lowered into the well on tubing, connected by a pipe, a gas separator is installed at the inlet of the centrifugal pump, and in the channel for supplying the pumped medium from the annulus of the well to the receiving chamber of the ejector is a check valve, according to the proposed technical solution

a receiver with a non-return valve is installed at the outlet of the centrifugal pump, while the liquid-jet ejector is made with passage sections of the nozzle and mixing chamber directly proportional to the flow rate and volume of the gas and inversely proportional to the depth of the dynamic level of the well fluid, and the centrifugal pump is selected with a pressure from the distribution of the lift pressure 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 the liquid a young ejector;

a packer with a cable entry above the channel for supplying the pumped medium from the annulus of the well into the receiving chamber of the liquid ejector can be installed on the tubing string.

The analysis of the prior art by the applicant has made it possible to establish that there are no analogs characterized by sets of features identical to all the features of the claimed method for producing a single-layer borehole fluid and a pump-ejector installation. 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 prototypes of the claimed technical solutions have shown that they do not follow explicitly from the prior art. From the prior art determined by the applicant, the influence of the transformations provided for by the essential features of the claimed technical solutions on the achievement of the specified technical result is not revealed. Therefore, each of the claimed technical solutions meets the condition of patentability "inventive step".

The claimed technical solutions can be implemented at engineering enterprises from well-known materials and technologies and used at wells in the oil industry to produce fluid from a single-layer well. Therefore, the claimed technical solution meets the condition of patentability "industrial applicability".

In this patent application, the requirement of unity of inventions is met, since the claimed method for producing a single-layer well fluid and a pump-ejector installation for its implementation are intended to increase the efficiency of production of a single-layer well fluid. The claimed technical solutions solve the same problem - increasing the efficiency of production of a single-layer borehole fluid.

Figure 1 schematically shows a pump-ejector installation for the production of a single-layer borehole fluid; figure 2 is the same equipped with a packer with cable entry.

The essence of the proposed method for the production of single-layer well fluid is as follows.

A centrifugal pump with a liquid jet ejector is installed in the well on a tubing string, the liquid jet ejector being higher than the dynamic level of the well fluid, and a gas separator is installed at the centrifugal pump intake. Then, the formation fluid is pumped from the bottom of the well into a gas separator, in which the formation fluid is separated and the released gas is sent to the annulus, and the separated fluid is injected by the laminar flow through the pipe into the nozzle of the liquid ejector. Simultaneously with the separated liquid, a gas jet ejector sucks the gas from the annulus of the well into the tubing string. Well fluid is produced by a centrifugal pump with a pressure set from the distribution of the pressure created by the centrifugal pump to lift the masses of gas-liquid mixture along the tubing string and the separated fluid through the pipe between the centrifugal pump and the liquid ejector and to lose pressure on the operation of the liquid ejector:

P ≥m _{MHC ESP} + m + p _{p tubing,}

where R _etsn - the pressure of the separated fluid created by a centrifugal pump;

m _mms is the mass of the separated liquid in the pipe between the centrifugal pump and the liquid jet ejector;

m _tubing is the mass of the gas-liquid mixture in the tubing string;

p _Page - pressure loss on the work fluid jet ejector.

The bore of the nozzle of the liquid jet ejector is made by a size directly proportional to the flow rate and inversely proportional to the depth of the dynamic level of the well fluid and is determined by the formula

where S _c - the area of the orifice of the nozzle of the liquid jet ejector,

Q is the flow rate of the well,

N is the depth of the dynamic level of the well fluid,

K ₁ - coefficient of proportionality.

The bore of the mixing chamber of the liquid jet ejector is made in a size directly proportional to the flow rate and volume of the gas and inversely proportional to the depth of the dynamic level of the well fluid and is determined by the formula

where S _to - the flow area of the mixing chamber of the liquid jet ejector,

Q is the flow rate of the well,

V is the volume of gas in the well,

N is the depth of the dynamic level of the well fluid,

K ₂ - coefficient of proportionality.

A pump-ejector installation for the production of a single-layer borehole fluid contains a centrifugal pump 2 with a submersible electric drive 3, lowered into the well at the tubing, 3, the latter being hermetically connected to the power cable 4, and a liquid-jet ejector 5 connected by a pipe 6. At the inlet of the centrifugal pump 2, a gas separator 7 is installed. In the channel 8 for supplying the pumped medium from the annulus 9 of the well to the receiving chamber 10 of the liquid-jet ejector 5, a check valve 11 is installed. At the outlet of the centrifugal Asosa 2 installed receiver 12 with a check valve 13 (Figure 1). The centrifugal pump 2 is selected with a pressure from the condition of the pressure distribution to lift the mass of the gas-liquid mixture along the tubing string 1 and the separated liquid through the pipe 6 between the centrifugal pump 2 and the liquid ejector 5 and the pressure loss on the operation of the liquid ejector 5. Passage sections of the nozzle 14 and the mixing chamber 15 of the liquid-jet ejector 5 is made with dimensions that are directly proportional to the flow rate Q and gas volume V and inversely proportional to the depth H of the dynamic level of the well fluid. The installation can be equipped with a packer 16 with a cable entry mounted on the column of tubing 1 above the channel for supplying the pumped medium from the annulus 9 of the well into the receiving chamber 10 of the liquid ejector 5 not more than 10 m (Figure 2).

An example implementation of a method of producing a single-layer borehole fluid using a pump-ejector installation for its implementation.

Formation fluid is pumped from the bottom of the well by the centrifugal pump to the wellhead 2 with a pressure, predeterminable of pressure distribution condition P _ESP in weight lifting m _CNT liquid mixture on a column of tubing 1, the mass of the tube 6 m _MHC separated liquid between the centrifugal pump 2 and liquid-jet ejector 5 and pressure loss p _pp to the operation of the liquid-jet ejector 5 from the conditions:

P _ESP ≥m _MHC M + + p _{p tubing.}

The cross section S _{c of the} nozzle 14 of the liquid jet ejector 5 is made directly proportional to the flow rate Q and inversely proportional to the depth H of the dynamic level of the well fluid and is determined by the formula

The cross section S _to the mixing chamber 15 of the liquid jet ejector 5 is made directly proportional to the flow rate Q and volume V of gas and inversely proportional to the depth H of the dynamic level of the well fluid and is determined by the formula

At the inlet of the centrifugal pump 2 in the gas separator 7, gas is separated from the reservoir fluid and the separated part of the gas is sent to the annulus 9, and the separated liquid is sent to the centrifugal pump 2. If there is a packer 16 with cable inlet, the part of the gas separated by separation is sent to the annulus 9 below the packer 16, forming a gas cap underneath. From the centrifugal pump 2, the fluid flows by turbulent flow into the receiver 12, in which the fluid pressure fluctuations caused by the pulsating flow and the intermittent fluid flow from the centrifugal pump 2 are smoothed out, and flows through the check valve 13 of the receiver 12 with a laminar flow through the pipe 6 to the nozzle 14 of the liquid-jet ejector 5, set above a dynamic level, and then through the receiving chamber 10 into the mixing chamber 15 of the liquid-jet ejector 5. Simultaneously with the separated liquid, the liquid-jet e a gas 5 is sucked out of the annulus 9 of the well through a check valve 11 through channel 8 and a receiving chamber 10 of the liquid ejector 5 to the tubing string 1. If there is a packer 16 with cable inlet, the gas is sucked out of the gas cap of the annulus 9 under the packer 16. From the mixing chamber 15 with a liquid-jet ejector 5, a gas-liquid mixture of fluid rises along the tubing string 1 at the wellhead, where gas is finally separated from the wellbore fluid to produce a clean product. After turning off the operation of the pump-ejector installation, the gas-liquid mixture in the tubing string 1, under the influence of its own weight, rushes back into the well and closes the check valve 11 in the channel 8 after the liquid jet ejector 5 and the check valve 13 of the receiver 12 in front of the centrifugal pump 2.

Using the proposed method for the production of a single-layer borehole fluid and a pump-ejector installation for its implementation will improve the efficiency of well operation and eliminate malfunctions in the pump-ejector installation, especially in a well with a high gas content.

Claims (3)

1. A method of producing a single-layer borehole fluid, including pumping the formation fluid with a centrifugal pump from the bottom of the wellhead, at the beginning of which the fluid is separated and the released gas is sent to the annulus, and the separated fluid is pumped by a centrifugal pump through a pipe into the nozzle of a liquid ejector, the latter being installed on the column tubing above the dynamic level of the borehole fluid, then gas is ejected from the annulus simultaneously with the ejector by the ejector two wells into the tubing string, characterized in that the separated fluid is injected into the nozzle of the liquid jet ejector by a laminar flow, and the production of the wellbore fluid is carried out by a centrifugal pump with a pressure set from the condition for the pressure distribution to lift the masses of gas-liquid mixture along the tubing string and separated fluid through the pipe between the centrifugal pump and the liquid jet ejector and the operation of the liquid jet ejector, taking into account the depth of the dynamic level of the borehole flui yes, at the same time, the flow sections of the nozzle and the mixing chamber of the liquid jet ejector are directly proportional to the flow rate and volume of the gas and inversely proportional to the depth of the dynamic level of the well fluid. 2. The pump-ejector installation for implementing the method according to claim 1, comprising an electric drive centrifugal pump and a liquid jet ejector, which are lowered into the well at the tubing, connected to each other by a pipe, a gas separator is installed at the inlet of the centrifugal pump, and the annulus of the well into the receiving chamber of the ejector is a check valve, characterized in that a receiver with a check valve is installed at the outlet of the centrifugal pump, while the liquid-jet ejector is made with the cross-sections of the nozzle and mixing chamber, which are directly proportional to the flow rate and volume of the gas and inversely proportional to the depth of the dynamic level of the well fluid, and the centrifugal pump is selected with a pressure from the condition of the pressure distribution to lift the masses of the gas-liquid mixture along the tubing string and the separated fluid through the pipe between the centrifugal pump and liquid jet ejector; and for the operation of a liquid jet ejector. 3. The pump-ejector installation according to claim 2, characterized in that a packer with a cable entry above the channel for supplying the pumped medium from the annular space of the well to the receiving chamber of the liquid-jet ejector can be installed on the tubing string.

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