WO2020225679A1

WO2020225679A1 - Method for extracting products from an oil well, installation for carrying out said method and downhole heating module

Info

Publication number: WO2020225679A1
Application number: PCT/IB2020/054120
Authority: WO
Inventors: Артем ГОЛУБОВ
Original assignee: Артем ГОЛУБОВ
Priority date: 2019-05-08
Filing date: 2020-04-30
Publication date: 2020-11-12

Abstract

The invention relates to means for extracting products from wells. The method consists in that a heater, a pump and sensors are lowered into a well. The heater is formed from series-connected modules, the temperature of each of which can be adjusted. The products in the well are heated and raised using the pump. The speed of said pump and the temperature of the modules are controlled on the basis of data received from the sensors. The technical result is increased efficiency.

Description

Method for producing oil well products, installation for its implementation and downhole heating module

The technical field to which the invention relates

The invention relates to a means of producing well products, and can be used, in particular, for intensifying oil and gas production.

State of the art

Known methods of extracting high-viscosity well products using screw pumping units, borehole sucker rod pumping units, installations of submersible electric centrifugal pumps (Ivanovsky V. I. and others. Downhole pumping units for oil production. Textbook. M .: GUP Publishing house " Oil and Gas "Gubkin Russian State University of Oil and Gas, 2002 - 824 pages).

A common disadvantage of all these methods is the significant effect of the rheological properties (for example, viscosity) of the produced product on performance indicators of pumping units, for example, the efficiency can be significantly reduced.

Also known from the prior art is a downhole heater that heats a gas-liquid mixture in a well (RU 2450117 C1, published on 05/10/2012), containing flow-through annular heaters at the end of the tubing for heating the gas-liquid mixture with paraffin at the bottom of the well and at the pump-compressor a pipe located above the electric centrifugal pump for additional heating of the gas-liquid mixture with paraffin, while all flow-through ring heaters are connected above the pump by a three-phase pump cable, and below by a single-phase cable. The disadvantage of this known tool is the complexity of its implementation, the impossibility of using for high-viscosity oils, the high cost and unreliability of the cable used, as well as the impossibility of maintaining the temperature of the produced product at a given value.

The closest analogue is a downhole heater described in the method of heating the bottomhole zone of a well (RU 2559975 C1, published on 08/20/2015), characterized in that one or more is lowered into the bottomhole zone of the well in the perforation interval on the liner from the tubing below the downhole submersible equipment. several interconnected borehole electric resistive heaters, produce controlled heating of the near-wellbore space of the bottomhole zone and the formation fluid entering the well, while in the lower pipe, on which the heater is reinforced, slot holes are made through which the heated borehole fluid moves freely from the annulus to the inner space of the tubing and vice versa, with the help of the control station, the necessary thermal effect is exerted on the bottomhole zone of the well. The disadvantages of the prototype are: low efficiency of heat removal from the surface of the heating element to the inner surface of the housing of the downhole heater, in addition, there is a large temperature difference at the boundary of the heat carrier / inner wall of the housing of the downhole heater, which requires a larger area of the outer surface of the housing of the downhole heater to remove a given power; in the case of an increase in the power of the downhole heater as the temperature of the working fluid rises, it is required to control the temperature of the elements with appropriate equipment, which leads to the complication of the design of the device; the use of the working fluid in the form of an intermediate heat carrier in the cavity of the downhole heater leads to an increase in the mass of the entire device under conditions of a limited diameter of the wells in comparison with direct heating devices; the use of the working fluid in the form of an intermediate heat carrier in the cavity of the downhole heater leads to excessive mass characteristics of the entire device under conditions of a limited diameter of the wells.

The essence of the invention

The invention solves the problem of changing the rheological properties of the extracted products of low viscosity for the possibility of using standard pumping units without reducing the efficiency of their work.

The technical result consists in increasing the efficiency and reliability of heating the oil well product due to the rational arrangement of the heating elements, efficient heat transfer to the environment and control of the pump operation.

The technical result is achieved by the fact that the method of producing oil well products consists in the fact that

- a heater, a pump and sensors are lowered into the well, said heater being installed under said pump;

- the said heater is made with the possibility of adjusting the rotation frequency; - said heater is made of series-connected heating modules, each of which is configured to regulate temperature;

- carry out heating of the product in the well and its lifting with the help of the said pump;

- the speed of rotation of said pump and the temperature of said heating modules are controlled according to data obtained from said sensors.

The technical result is achieved by the fact that the installation for implementing the method contains

- a pump made with the possibility of speed control;

- a heater installed under the said pump and made of series-connected heating modules, each of which is configured to control the temperature;

- Control block;

- sensors for placement in the well;

- said control unit is configured to control the rotation speed of said pump and temperature of said heating modules according to data obtained from said sensors.

The technical result is also achieved by the fact that the downhole heating module contains

- suspension;

- body;

- heating elements;

- current lead;

- temperature sensor;

- said body is made in the form of a hollow cylinder; - said heating elements are located along the outer surface of said housing and are located at the vertices of an equilateral triangle;

- said heater is configured to control and maintain a predetermined temperature in a constant or short-term cyclic heating mode using a control system.

The technical result is also achieved by the fact that the module is connected to the geocable control unit.

The technical result is also achieved by the fact that the module is made with the ability to connect with other modules using a tool selected from the group: flange connection, cable, chain.

The technical result is also achieved by the fact that the heating elements are made of an induction and / or resistive principle of operation.

The technical result is also achieved by placing ribs on the outer surface of the heater body.

A distinctive feature of the present invention is the implementation of the heater in the form of several heating modules equipped with a temperature sensor, and the location of the heating modules below the pump.

List of drawing figures

Figure 1 shows a downhole heater.

Fig. 2 is an enlarged view of A in Fig. 1.

Fig. 3 shows the layout of the pumping unit and heater in the well.

Figure 4 shows a diagram of a pump and heater control unit in the well. Implementation of the invention

Due to the significant depletion of easily recoverable oils, it became necessary to develop new technologies for the production of hard-to-recover reserves, including high-viscosity ones.

A common disadvantage of the known downhole heaters for high-viscosity products is the impossibility of controlling the temperature of the product in production wells during its production, and, accordingly, its rheological properties, which leads to the need to use pumping units designed for the production of high-viscosity products that may have a high initial temperature. This is due to the fact that the thermal effect is generally applied to the reservoir to increase its oil recovery, and not to the product already in the producing well.

The present invention provides an increase in oil and gas production, optimization of high-viscosity well production processes by using the combined operation of pumping and thermal equipment to change the rheological properties (for example, viscosity) of the produced well products. The invention is aimed at changing the rheological properties of the produced reservoir products to increase oil recovery by reducing the viscosity of the produced products.

The proposed downhole heater makes it possible to produce high-viscosity downhole products using any pumps without significantly changing their characteristics, for example, the efficiency. This is achieved by heating the produced product inside the well, which leads to a change in its rheological properties, in particular, a decrease in viscosity.

Of the pump types traditionally used for oil extraction, screw pumps are the most suitable for the extraction of high-viscosity products. Subsurface screw pumps operate by transferring energy in the form of a rotating string of sucker rods from an electric motor installed at the wellhead or by transferring energy from a submersible electric motor.

The downhole heater (see Fig. 1-2) contains a suspension 7, a housing in the form of a hollow cylinder (not designated by a separate position), heating elements (not designated by separate positions) and a current lead. In this case, the heating elements are located along the outer surface of the housing and are placed along the vertices of an equilateral triangle. The heater is configured to maintain a predetermined temperature as a result of constant or short-term cyclic heating controlled and / or set by the control system. In addition, the heater is connected to the geocable 21 control unit (Fig. 3).

The heater is modular, the number of modules 8, 9, 10 (Fig. 1) is selected depending on the required power and can be from 2 to 12 pieces. Each module 8, 9, 10 is equipped with a closed-loop temperature sensor. In this case, the modules are connected to each other using a flange connection, or using cables, or chains, or flexible connection.

Heating elements (Fig. 3) are made of induction and / or resistive principle of operation. In this case, the cavity of the cylinder is filled with a heat-conducting material. Ribs are placed on the outer surface of the heater body 1.

The heater (Fig. 1) contains pins 1 and nuts 2 for attaching the upper module to the suspension 7, a gasket 3 (for example, paronite), a spring washer 5, a bolt 6, a plug 11 and an O-ring 4 (Fig. 2).

Let us consider an example of a layout and a method of using a pumping unit and a heater in a well (Fig. 3) with a complete set of equipment for a variable frequency drive and a downhole heater of a unified type. When implementing the method, the energy consumption of the pumping unit is reduced by reducing the viscosity of the liquid, it becomes possible to replace the pumping unit with a pumping unit with a lower power.

Collect the installation run down into the well (Fig. 3), consisting of heater 1, pump 2, tubing 3, check valve 4, branch pipe (1/2 m) 5, whipped valve 6, branch pipe (1/2 m) 7 , Rudak rings 8, tubing strings 9, klyams 10, two-channel protector 11 on all tubing couplings, cable 12, wellhead fittings 13 with two cable entries, terminal box 14, control station 15, transformer 16, double branch pipe 17, couplings 18, protection of the end device 19, thermal converter 20, geocable 21. Clamps (for example, model PKK 73) are installed on each tubing, three pieces. Cable protectors (for example, models PK 73/2) are installed on all tubing couplings. Heater 1 and the pumping unit are lowered into the well, the product is heated and lifted out of the well using pump 2, while using the control unit 15, the preset temperature of heater 1 is maintained. Heater 1 is installed under the pumping unit, while heating is performed continuously or for a short time. cyclically, and the heating temperature and the mode of operation of the heater are controlled and / or set using the control unit 15, which is part of the pumping station control station or installed separately.

The pumping unit and heater are controlled by signals from process parameters sensors. The heater 1 is connected to the control unit 15 by a geocable 21. The heater 1 is modular, the number of modules is selected depending on the required power and ranges from 2 to 12 modules. The modules are connected to each other using a flange connection, or using cables, or chains, or a flexible connection. Each heater module 1 consists of several electric heating elements, which are placed in the heater at the vertices of an equilateral triangle, while the cylinder cavity is filled with heat-conducting material. Each module is equipped with a closed loop temperature sensor. In addition, ribs are placed on the outer surface of the heater body. The heater 22 and the pumping unit are lowered into the well, the product is heated and lifted out of the well using the pump 23, while using the control station 15, the preset temperature of the heater 22 is maintained, the heater 22 is installed under the pumping unit, while heating is performed continuously or for a short time. cyclically, with the heating temperature and the heater operating mode being controlled and / or set using the control system 15, which is part of the pump unit control station or installed separately, while the pump unit and the heater are controlled according to signals from the process parameter sensors. The heater 22 is connected to the control station 15 by a geocable 21. In addition, the heater 22 is modular, the number of modules is selected depending on the required power and ranges from 2 to 12 modules. In addition, the modules are connected to each other using a flange connection, or using cables, or chains, or flexible connection. In addition, the heater 22 is selected from an inductive and / or resistive operating principle. Each heater module 22 consists of several electric heating elements, which are placed in the heater along the vertices of an equilateral triangle, while the cylinder cavity is filled with a heat-conducting material. In addition, each module is equipped with a closed loop temperature sensor. In addition, ribs are placed on the outer surface of the heater body.

A functional diagram of a control system for wells with high viscosity products is shown in Fig. 4 when the variable frequency drive and the downhole heater work together. The control controller 37 regulates the rotation speed of the drive motor 33 by means of the frequency converter 34. At the same time, the downhole heater is controlled unified type 35. By generating a signal for the power unit 36. Structurally, the controller 37, the frequency converter 34 and the power supply unit 36 can be installed both in the control unit of the downhole 15 (Fig. 3), and separately for the purpose of unification with the existing equipment stock. Control is carried out according to signals from sensors of technological parameters 381, 382, ..., 38p. The composition of the sensors varies depending on the well design, system configuration and the type of pump used.

The maximum efficiency of the invention is achieved when the downhole heater provides a temperature regime of operation in the range from the pour point of paraffins and resins contained in the produced product (for example, oil emulsion) to the temperature of emulsion coking.

This result is achieved by combining the operation of a pumping unit with a frequency-controlled drive, as well as constant and / or short-term cyclic heating of the produced product inside the well using electric heating equipment, due to which its rheological properties change, in particular, the viscosity decreases, which reduces or eliminates decrease in the energy characteristics of downhole pumping units and makes it possible to use pumping units, in particular, installations of submersible electric centrifugal pumps, without a significant margin in pressure, power and flow. Thus, the efficiency of the production of viscous oil well products is increased due to the joint control of the pumping unit and the downhole heater according to the data from the process parameters sensors.

With regard to the downhole heater, the technical result consists in increasing the efficiency and reliability of the downhole heater due to the rational arrangement of the heating elements and efficient heat transfer to the environment.

The conducted patent analysis revealed differences from the prior art, and therefore the proposed heater meets the criterion patentability "novelty". The proposed heater can be implemented with equipment manufactured by the industry using known materials and technologies, produced and successfully passed downhole tests, and therefore the proposed heater meets the criterion of patentability "industrial applicability".

It should be understood that after a specialist considers the above description with an example of implementation of a downhole heater and the layout of the pumping unit and heater in the well, as well as the accompanying drawings, other changes, modifications and implementations of the claimed invention will become apparent to him. Thus, all such changes, modifications and implementation options, as well as other areas of application that do not differ from the essence of this utility model, should be considered protected by this utility model within the scope of the attached claims.

Claims

Claim

1. A method of producing oil well products, consisting in the fact that

- the said heater is made with the possibility of adjusting the rotation frequency;

- said heater is made of series-connected heating modules, each of which is configured to regulate temperature;

2. Installation for implementing the method according to claim 1, comprising

- a pump made with the possibility of speed control;

- Control block;

- sensors for placement in the well;

3. Downhole heating module for implementing the method according to claim 1, comprising

- suspension;

- body; - heating elements;

- current lead;

- temperature sensor;

- said body is made in the form of a hollow cylinder;

- the said heating elements are located on the outer surface of the said body and are placed at the vertices of an equilateral triangle;

4. The device according to claim 3, characterized in that it is connected to the geocable control unit.

5. The device according to claim 5, characterized in that it is made with the possibility of connecting with other modules using a means selected from the group: flange connection, cable, chain.

6. The device according to claim 3, characterized in that the heating elements are made of an inductive and / or resistive principle of operation.

7. The device according to claim 3, characterized in that ribs are placed on the outer surface of the heater body.