RU2550613C2 - Method of extraction of fluid from two layers of one well and pump-ejector unit for its implementation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method comprises pumping oil from a lower layer by the centrifugal pump with feeding under pressure of liquid jet ejector into the nozzle. Using this ejector the oil from the upper layer is simultaneously pumped with oil from the lower layer through the column of oil-well tubing to the wellhead. At that the oil from the lower layer is pumped to the nozzle of the liquid jet ejector with laminar flow of oil flow with low gas content. Pumping oil at the wellhead is carried out with a centrifugal pump with the pressure given by the condition of the pressure distribution on the rise of the oil masses from the lower layer to the nozzle of the liquid jet ejector and oil mixture from both layers along the column of oil-well tubing and the work of the liquid jet ejector. The flow cross-sections of the nozzle and the mixing chamber of the liquid jet ejector are set directly proportional to production rate of the lower layer and the production rate of both layers of the wells, respectively.

EFFECT: increase in reliability of operation of the well.

3 cl, 2 dwg, 1 ex

Description

The group of inventions relates to the field of mining, in particular to oil production, and can be used for oil production from two layers of one well, mainly with a low gas content.

A known method of producing fluid from two reservoirs of one well, including descent into the well at the tubing string of at least one packer to separate the wellbore, liquid ejector and centrifugal pump, pumping fluid from the lower reservoir by a centrifugal pump with a pressurized liquid nozzle ejector, the last simultaneously with the fluid from the lower reservoir pump fluid from the upper reservoir along the string of tubing at the wellhead.

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, IPC F04F 5/54, publ. 03/20/2014. In-line well pump unit.) This technical solution is taken as a prototype.

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

The main task, which is claimed by the claimed technical solutions, is to increase the efficiency of wells by eliminating failures in the operation of a liquid-jet ejector with a gas content of less than 100 m ³ / t in oil.

The technical result is to increase the efficiency of wells with a gas content of less than 100 m ³ / t due to the elimination of failures in the operation of a liquid jet ejector.

The specified technical result is achieved by the fact that in the known method of extracting oil from two layers of one well, separated by a packer, including pumping oil from the lower layer by a centrifugal pump with a pressurized liquid ejector, the latter simultaneously pumping oil from the lower layer to the oil from the upper layer along the string of tubing at the wellhead, according to the proposed technical solution, oil from the lower reservoir is injected into the nozzle of a liquid-jet ejector by a laminar flow outflow of oil with a low gas content, and the pumping of oil at the wellhead is carried out by a centrifugal pump with a pressure set from the condition for the pressure distribution to lift the mass of oil from the lower reservoir to the nozzle of the liquid ejector and the mixture of oil from both reservoirs along the tubing string and to work liquid ejector, while the bore of the nozzle and the mixing chamber of the liquid ejector are set directly proportional to the flow rate of the lower reservoir and the flow rate of both layers of the well, respectively.

The specified technical result is achieved by the fact that in the known pump-ejector installation for oil production from two layers of one well, containing an electric drive centrifugal pump with a power cable lowered into the well on the 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, according to the proposed technical solution,

a receiver is installed at the outlet of the centrifugal pump, connected by a pipe to the entrance to the nozzle 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 above the channel for supplying oil from the upper wellbore to the receiving chamber of the liquid jet ejector.

The analysis of the prior art by the applicant has made it possible to establish that there are no analogues that are characterized by sets of features that are identical to all the features of the claimed method for producing oil from two layers of one well 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 used in wells for oil production from two layers of one well with a gas content of less than 100 m ³ / t in oil. Therefore, the claimed technical solution meets the condition of patentability "industrial applicability".

In the present application for the grant of a patent, the requirement of unity of inventions is met, since the claimed method of oil production from two layers of one well and a pump-ejector installation for its implementation are intended to increase the efficiency of oil production. The claimed technical solutions solve the same problem - increasing the efficiency of oil production.

In FIG. 1 schematically shows a pump-ejector installation for oil production from two layers of one well; in FIG. 2 - the same, equipped with an additional packer with cable entry.

The essence of the proposed method of oil production from two layers of one well is as follows.

Oil is extracted from two layers I and II of one well, separated by a packer, by a centrifugal pump with pumping out oil with a low gas content (less than 100 m ³ / t) from the lower layer I by a laminar flow of oil through the pipe into the nozzle of a liquid ejector, the latter being simultaneously pumped out oil from the upper formation II along the tubing string at the wellhead. Oil is pumped out by a centrifugal pump with a pressure set from the condition for the pressure distribution to lift the masses of oil from the lower layer of the first well in the pipe into the nozzle of the liquid ejector and the mixture of oil from both layers of the second and second columns of the tubing at the wellhead and for the operation of the liquid ejector, which is determined from the condition:

P ≥t _{MHC ESP} + m + p _{p tubing,}

Where

R _etsn - the pressure of oil created by a centrifugal pump;

t _mnc is the mass of oil between a centrifugal pump and a liquid jet ejector;

t _tubing - the mass of the mixture of oil from both reservoirs of I and II wells in the tubing string;

p _p - pressure loss on the work of a liquid ejector.

The bore of the nozzle of the liquid jet ejector is made in a size directly proportional to the flow rate Q _{1 of the} lower formation I of the well, and is determined by the formula:

S _c = K ₁ · Q ₁ ,

Where

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

Q ₁ - flow rate of the lower layer I of the well,

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 sum of flow rates (Q ₁ + Q ₂ ) of both layers of the first and second wells, and is determined by the formula:

S _k = K ₂ · (Q ₁ + Q ₂ ),

Where

S _k - the area of the bore of the mixing chamber of the liquid jet ejector,

Q ₁ - flow rate of the lower layer I of the well,

Q ₂ - flow rate of the upper reservoir II of the well,

K ₂ - coefficient of proportionality.

A pump-ejector installation for oil production from two layers of one well contains a centrifugal pump 2 with a submersible electric drive 3, lowered into the well by tubing 1, the latter being hermetically connected to the power cable 4 of the power supply of the drive 3 of the centrifugal pump 2, a liquid-jet ejector 5 and at least at least one packer 6 with cable entry, separating the lower layer I and upper layer II in the annulus 7. At the outlet of the centrifugal pump 2, a receiver 8 is installed, connected by a pipe 9 to the entrance to the nozzle 10 of the ejector 5. On the outlet valve 11 is installed with a check valve 11. In the channel 12 for supplying oil from the upper formation II of the well to the receiving chamber 13 of the ejector 5, a second check valve 14 is installed (Fig. 1). The liquid-jet ejector 5 is made with a passage section of the nozzle 10, directly proportional to the flow rate Q _{1 of the} lower formation I of the well, and with a passage section of the mixing chamber 15, directly proportional to the flow rate of both layers I and II of the well. An additional packer 16 can be installed on the tubing string 1 with a cable entry above the channel 12 for supplying oil from the upper formation II of the well to the receiving chamber 13 of the ejector 5, eliminating the possible depression of the upper formation I of the well (Fig. 2).

An example of the method of oil production from two layers of the same well using a pump-ejector installation for its implementation

An electric drive centrifugal pump 2 with a submersible electric drive 3 and a power cable 4, a liquid-jet ejector 5 and at least one packer 6 with a cable entry, separating the well strata, are installed in the well on the tubing string 1. Oil with a gas content of less than 100 m ³ / t is evacuated simultaneously from the top layer II at a flow rate Q ₂ = 20 m ³ / day and from the lower reservoir I at a flow rate Q ₁ = 60 m ³ / day at the wellhead centrifugal pump with a pressure P 2 = 9.7 MPa _ESP, predeterminable from the condition of the distribution of pressure P _ect on the increase in mass t _mnc oil from the lower layer I through pipe 9 to the nozzle 10 of the liquid ejector 5 and the mass t of _oil mixture of both layers of I and II wells along the tubing string 1 and the pressure loss p _p for the operation of the liquid ejector 5, from the condition:

P ≥t _{MHC ESP} + m + p _{p tubing.}

To fulfill this condition, the orifice S _{c of the} nozzle 10 of the liquid-jet ejector 5 is made with a diameter of 3.8 mm, which is directly proportional to the flow rate Q _{1 of the} lower layer I according to the formula:

S _c = K ₁ · Q ₁ .

The cross section S _{k of} the mixing chamber 15 of the liquid-jet ejector 5 is made with a diameter of 5.4 mm, which is directly proportional to the flow rate (Q ₁ + Q ₂ ) of both reservoirs I and II of the well, according to the formula:

S _k = K ₂ · (Q ₁ + Q ₂ ).

From the centrifugal pump 2, the oil of the lower reservoir I with a gas content of less than 100 m ³ / t and flow rate Q ₁ = 60 m ³ / day flows into the receiver 8 in a turbulent flow, in which the pressure fluctuations of the oil are smoothed out due to the pulsating flow and intermittent oil flow from a centrifugal pump 2, flows through the check valve 11 of the receiver 8 with a laminar flow with a pressure of R _ect = 9.7 MPa through the pipe 9 into the nozzle 10 with a diameter of 3.8 mm of a liquid-jet ejector 5 and then through a receiving chamber 13 into a mixing chamber 15 with a diameter 5.4 mm liquid jet ejector 5. Simultaneously with the oil from the lower layer I, a liquid-jet ejector 5 pumps oil from the upper layer II with a flow rate of Q ₂ = 20 m ³ / day through the annulus 7 of the well, a check valve 14 through channel 12 and a receiving chamber 13 of the liquid-jet ejector 5 to the pump casing -compressor pipes 1. From the mixing chamber 15 with a liquid-jet ejector 5, a mixture of oil from both reservoirs I and II with a flow rate of 80 m ³ / day rises with a pressure of 5.0 MPa along the string of tubing 1 at the wellhead. After shutting down the operation of the pump-ejector installation, oil from the tubing string 1, under the influence of its own weight, rushes back into the well and closes the check valve 14 in the channel 12 after the receiving chamber 13 of the liquid jet ejector 5 and the check valve 11 of the receiver 8 in front of the centrifugal pump 2.

Using the proposed method of oil production from two layers of one well and a pump-ejector installation for its implementation will improve the efficiency of wells with a gas content of less than 100 m ³ / t and eliminate malfunctions in the operation of a liquid-jet ejector of the installation.

Claims (3)

1. A method of extracting oil from two layers of the same well, separated by a packer, including pumping oil from the lower layer by a centrifugal pump with a pressurized liquid ejector into the nozzle, the latter simultaneously pumping oil from the lower layer from the upper layer through a tubing string into wellhead, characterized in that oil from the lower reservoir is injected into the nozzle of the liquid jet ejector by a laminar flow of oil flow with a low gas content, and pumping oil at the wellhead produces prices a submersible pump with a pressure set from the condition for the pressure distribution to lift the masses of oil from the lower layer into the nozzle of the liquid jet ejector and the mixture of oil from both layers along the tubing string and to the operation of the liquid jet ejector, while the nozzle and the mixing chamber of the liquid jet ejector pass through directly proportional to the flow rate of the lower layer and the flow rate of both layers of the well, respectively.  2. A pump-ejector installation comprising an electric drive centrifugal pump with a power cable lowered into a well on a tubing string, a liquid-jet ejector connected to the nozzle inlet with a pipe in which a non-return valve is installed, and at least one packer with a cable entry, uncoupling the well strata, characterized in that a receiver is installed at the outlet of the centrifugal pump, connected by a pipe to the entrance to the nozzle of the liquid-jet ejector, a check valve is installed at the outlet of the receiver, and a fluid in the supply channel and a second non-return valve is installed from the upper wellbore into the receiving chamber of the liquid-jet ejector, while the liquid-jet ejector is made with flow-through sections of the nozzle and mixing chamber directly proportional to the flow rate of the lower layer and the flow rate of both well layers, respectively. 3. The pump-ejector installation according to claim 2, characterized in that an additional packer is installed on the tubing string with a cable entry at a level above the channel for supplying fluid from the upper formation to the receiving chamber of the liquid ejector.

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