RU2402715C1 - System for transporting gas-water-oil mixture at field - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: system consists of line for supply of product from wells with two pipe branches for supply of gas saturated flow into jet pump coupled with separating installation and power block via system of pipelines. The pipe branches ensure division of gas-liquid mixture entering the jet pump from wells into a passive gas-saturated flow and passive liquid-gas medium. Also the passive gas-saturated flow enters an internal stepped channel of a hollow cylinder tube installed coaxially inside a nozzle of the jet pump and forming a circular nozzle of alternate cross section with its external surface and with internal surface of the nozzle along its whole length. The active flow of circulating water-oil mixture is supplied into the circular nozzle of alternate cross section from the separating installation by means of an electro-centrifugal pump via the internal channel of the tubing of the power block.

EFFECT: raised efficiency of installation.

2 dwg

Description

The invention relates to the field of oil production, in particular to field gathering and transportation of a gas-liquid mixture of oil well products during single-pipe transportation to an oil treatment unit at a central oil collection and preparation point. The invention can also be used in other sectors of the economy for pumping and transportation of multiphase mixtures.

The prior art installation for collecting and transporting oil well products (RF patent No. 2160866, class F17D 1/00, published date 1999), including a network of prefabricated pipelines from wells, a pressure pipeline to an oil treatment unit and a pumping unit, located between the network of prefabricated pipelines and the pressure pipe. The pump installation was performed using a multiphase sucker rod pump mounted on a tubing and installed in a sump equipped with a large diameter pipe with a plug at the lower end and wellhead equipment at the upper end. The side outlet of the sump connected to the annulus is connected to the network of prefabricated pipelines through an expansion chamber, and the side outlet of the wellhead equipment is a linear outlet of the wellhead equipment that communicates with the internal cavity of the tubing and is connected to the pressure pipe through an ejector, which is connected to the gas space via a gas line expansion chamber.

However, this known installation does not provide a stable and constant mode of transportation of the gas-oil mixture from wells with high production rates, as well as with a high gas factor and a high content of solids.

The closest to the proposed technical solution for the totality of signs is a system for collecting and transporting oil well products (RF patent No. 2236639, class F17D 1/00, published date 09/20/2004), containing a gas-liquid mixture delivery line, an ejector containing a nozzle , a receiving chamber and a diffuser, a tube separation unit (tube phase divider), which contains a discharge of gas-containing separation products associated with a pressure pipe, and a discharge of gas-liquid separation products connected by a bypass line to a new unit made in the form of an electric centrifugal pump placed in a cased casing with a plug on the lower end of the sump and mounted on the tubing tubing, the cavity of which is hydraulically connected through a linear outlet of the wellhead equipment of the sump with an ejector nozzle, and the annulus of the sump is connected by bypass lines with the discharge of gas-liquid separation products, while the ejector diffuser is connected to the input of the separation unit.

The specified system for collecting and transporting oil well products provides the supply of a gas-liquid mixture from the wells through automated group metering units to receive an ejector, then to a pipe phase divider, where the mixture is separated into gas-containing and gas-liquid parts. The gas-containing part is discharged into the pressure pipe into the transport system to the oil pre-treatment unit (UPPN), and the gas-liquid part to the reception of an electric centrifugal pump mounted on the tubing and installed in the sump (well).

The gas-liquid mixture, which is the working fluid, under the pressure developed by the pump, enters the nozzle of the ejector, which ensures the suction of well products, mixing with the working fluid and compressing the mixture to the pressure of separation and transportation of the product.

The disadvantage of this system is the decrease in the efficiency (efficiency) of the installation in the presence of a high gas factor of a gas-liquid mixture leaving the tube phase divider and which is a working fluid.

The technical result achieved by the proposed transportation system of the gas-oil mixture in the field is to increase the productivity of the installation.

The specified technical result is achieved due to the fact that the gas-liquid mixture collection and transportation system includes a production line from the wells, connected by a pipeline through a pipe outlet with an ejector connected at the outlet by a pipeline with a separation unit, which includes a pipe for discharging the separated gas-liquid mixture into the transport pipeline and a pipe for diverting the separated oil-water mixture into the pipeline connecting the separation unit with the annular space of the silovog the block located in the sump, while the power block includes a submersible electric motor connected in series from the bottom up, an electric centrifugal pump and a tubing connected tightly by a pipeline with an ejector, while in the upper part of the well production supply line there is an additional pipe branch connected by a pipeline for transportation passive gas-saturated flow into the inner cylindrical step channel of a hollow cylindrical tube mounted concentrically inside the ejection nozzle and forming its outer surface and the inner surface of the annular nozzle ejector nozzle, a conduit connected with an internal channel tubing power unit for supplying active back-water mixture into the annular ejector nozzle.

Thus, the indicated technical result, which consists in increasing the productivity of the installation, is achieved due to the fact that three flows are fed into the ejector mixing chamber — the active stream of the oil-water circulating oil-oil mixture leaving the annular nozzle of the ejector with a high pressure and high speed, causing a rarefaction in the ejector mixing chamber, thereby providing injection into the mixing chamber of the production of wells in the form of two passive flows with low pressure - a liquid-gas medium flowing through the connecting pa cutting the ejector, and a gas-saturated stream flowing through the inner channel of the hollow stepped cylindrical tube mounted concentrically within an ejector nozzle.

Figure 1 shows a process diagram of a system for transporting a gas-oil mixture in a field; figure 2 is a schematic diagram of the ejector used in the proposed system.

The inventive system for transporting a gas-oil mixture in the field (Fig. 1) contains a line 1 for supplying products from wells, two pipe bends — a pipe branch 2 installed in the upper part of the line 1 for supplying products and connected by a pipe 3 with an ejector 4, as well as a pipe branch 5, connected by a pipe 6 to an ejector 4, which is connected at the outlet by a pipe 7 to a separation unit 8, which includes a pipe 9 for discharging the separated gas-liquid mixture into the transport pipeline, and a pipe 10 for discharging the separated th-water mixture in the conduit 11 connecting separation unit 8 to the annulus of the power unit 12 is disposed in the sump. The power unit 12, including a submersible electric motor (SEM) connected in series from bottom to top, an electric centrifugal pump (ESP) and a tubing (Tubing), is hermetically connected by a pipe 13 to the ejector 4 in such a way that it has a through channel with an annular nozzle 15 of the ejector 4, formed by the inner surface of the nozzle 14 and the outer surface of the hollow cylindrical tube 16 mounted concentrically to the nozzle 14 along its entire length. The inner step channel of the hollow cylindrical tube 16 (Fig. 2) is directly connected through the channel with the receiving chamber 17, the mixing chamber 18 and the diffuser 19 of the ejector 4, connected by a pipe 7 to the separation unit 8.

The proposed system for transporting gas-oil mixture in the field works as follows.

To bring the installation into operation, a gas-oil mixture under pressure, for example, 0.1-1.2 MPa, is supplied to the supply line 1 from the wells, while a gas-saturated stream (passive) with a high gas content is sent to pipe branch 2, and liquid -gas medium (passive) with a lower gas content is sent to the connecting pipe 5. Forming passive flows, the liquid-gas medium flows through the pipe outlet 5 and pipe 6 into the receiving chamber 17 of the ejector 4, and the gas-saturated stream flowing through the pipe outlet 2 and the pipeline 3 also enters the receiving chamber 17 of the ejector 4, having previously passed through the internal stepped channel of the hollow cylindrical tube 16 mounted concentrically in the nozzle 14 of the ejector 4. Passing from the receiving chamber 17 into the mixing chamber 18 through the diffuser 19 of the ejector 4, the mixture of two low passive flows pressure, for example, 0.1-1.2 MPa, and a high-pressure stream (active) coming from the power unit 12, for example, with a pressure of 8.0-18.0 MPa, is sent through pipeline 7 to the separation unit 8 with pressure necessary for further transportation gazovodoneftyanoy mixture. The gas-liquid stream leaving the separation unit 8 is directed through branch 9 to the transport pipeline, and the oil-water mixture also leaving from the separation unit 8 is directed through branch 10 and pipe 11 into the annulus of the sump of the power unit 12. Having passed along the SEM, the water-oil mixture is recycled arrives at the ESP, at the outlet of which there is already a stream of active circulating oil-water mixture with high pressure, for example 8.0-18.0 MPa. Next, the active circulating oil-water mixture through pipeline 13 enters the annular nozzle 15 of the ejector 4 and, leaving it with high speed and high pressure, causes a rarefaction in the mixing chamber 18 of the ejector 4, thereby providing injection of two passive flows with low pressure, for example 0, 1-1.2 MPa, into the ejector 4: a liquid-gas medium entering the receiving chamber 17 through the connecting pipe 5 and pipe 6, and a gas-saturated stream entering through the pipe outlet 2, pipe 3 and the inner channel of the hollow cylindrical tube 16.

Due to this design, at the outlet of the diffuser 19 of the ejector 4, the gas-oil flow directed to the separation unit 8 will always have the required transportation pressure, for example, 1.5-4 MPa, regardless of the composition of the wells. At the same time, the efficiency of the installation increases with a high gas factor (up to 100%). Such a closed cycle is the basis of the proposed system for transporting a gas-liquid mixture in the field.

The installation, made in accordance with the proposed gas-oil mixture transportation system at the field, was installed at LUKOIL-PERM LLC at DNS 0113 of the Chernushinsky field in the Perm Territory and is being operated with a positive result.

Claims (1)

A system for collecting and transporting a gas-liquid mixture, including a line for supplying production from wells, connected by a pipeline through a pipe outlet with an ejector connected at the outlet to a separation unit, including a pipe for draining the separated gas-liquid mixture into the transport pipeline, and a pipe for draining the separated oil-water mixture into the pipeline connecting the separation unit with the annulus of the power unit located in the sump, while the power unit includes Submersible electric motor, electric centrifugal pump and tubing connected in series from bottom to top, hermetically connected by a pipeline with an ejector, characterized in that in the upper part of the well production supply line there is additionally made a pipe outlet connected by a pipeline for transporting a passive gas-saturated stream into the hollow cylindrical step channel a cylindrical tube mounted concentrically inside the ejector nozzle, forming its outer surface and inner The rim surface of the nozzle is an annular ejector nozzle connected by a pipeline to the internal channel of the power unit tubing for supplying an active circulating oil-water mixture to the annular ejector nozzle.

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