RU102672U1 - INSTALLING A SUBMERSIBLE CENTRIFUGAL PUMP - Google Patents

Abstract

 Installation for oil production, containing a submersible electric pump unit that combines an electric motor with hydraulic protection, a pump and a cable line, lowered into the well on lifting tubing, wellhead equipment, a control station and a transformer, characterized in that in the lower part of the installation through a threaded nipple an electrode insulated from the installation casing and production casing is installed and is connected via an additional cable to the positive pole of the DC source (cathodic station shields) installed on the earth's surface, the negative pole of which is connected to the wellhead.

Description

The utility model relates to the oil industry and can be used to intensify oil production by rodless pumps in difficult geological conditions.

A well-known downhole pump is a vertical single-acting structure with a fixed cylinder, a movable metal plunger and ball valves; lowered into the well on a string of tubing and sucker rods (1). Oilfield Equipment: Handbook / Ed. EI Bukhalenko 2nd ed., Revised and supplemented by M .: Nedra, 1990. - 559 pp., Ill. - analogue.

The disadvantage of a downhole pump is its applicability only in low-yield wells and the need to use complex metal-intensive ground equipment (rocking machine), as well as its limited applicability with a large gas factor and a large curvature of wells, typical for cluster drilling.

The aim of the invention is to increase the efficiency of lifting in difficult geological and technical conditions; deviated wells and with intense corrosion. The closest technical solution is the installation of a submersible centrifugal pump, which includes a submersible electric pump unit, which combines an electric motor with hydraulic protection, a pump and a cable line, lowered into the well by lifting tubing; mouth equipment; a control station and a transformer, which are installed at a distance of 20-30 m from the wellhead. (2) Oilfield equipment: Handbook / Ed. EI Bukhalenko 2nd ed., Revised and supplemented - M .: Nedra, 1990. - 559 p.: Silt, - prototype.

However, the disadvantage of this device is reduced performance under complicated geological conditions, increased viscosity, significant gas factor and corrosion insecurity of oilfield equipment in conditions of increased aggressiveness of the lifted fluid.

The goal is achieved by the fact that an electrode isolated from the installation casing and production casing is installed through a threaded nipple in the lower part of the installation, and through an additional cable it is connected to the positive pole of the DC source (cathodic protection station) installed on the earth's surface, the negative pole of which is connected to the wellhead.

The proposed design will allow the formation of a sufficient cathode potential, relative to the anode-charged electrode, and to protect the downhole equipment from electrochemical corrosion on the installation casing and the lower part of the production string in an electrically conductive medium (water emulsified in oil).

In FIG. The inventive device is schematically depicted.

Installation of a submersible centrifugal pump consists of a submersible pump unit, consisting of a submersible centrifugal pump 1 and motor 2 (electric motor with hydroprotection), cable assembly 3, lowered into the well on the tubing string 4, ground-based electrical equipment - transformer complex substation 5, cable providing energy supply to the electric motor, which is attached to the hydroprotection, the pump and tubing pipes with metal belts 6, which are part of the pump. In the end part of the motor housing through a threaded nipple 7, a pin 8, insulating inserts 9, and an insulator 10, an electrode 11 made of corrosion-resistant steel, a nut 12 and o-rings 13 and 14 are placed. The device includes a cathodic protection station 15, cable 16 and a section cable 17. Moreover, the “positive” terminal of station 15 is connected via cable 16 to the built-in electrode 11, and “negative” - to the wellhead.

The device operates as follows. Below a submersible centrifugal pump, under the action of an created electric field, water emulsified in oil and containing salt solutions decomposes as a result of secondary electrical reactions into hydrogen molecules H ₂ from H atoms at the cathode (protected equipment) and oxygen molecules O ₂ from OH radicals at the anode (electrode 11 ) Also, in addition to the cathodic polarization of downhole equipment, due to secondary electrochemical reactions, a protective, smooth, passivating black Fe ₃ O ₄ magnetite film is formed on the metal surface of the body elements, which prevents further corrosion. At the same time, due to the degassing of water, and the formation of gas bubbles, conditions are created that prevent the deposition of salts on the surface of the columns and the formation of a highly dispersed gas-liquid mixture of reduced density, which contributes to the creation of additional depression on the reservoir.

Information sources:

1. Oilfield equipment: Handbook. / Ed. E.I. Bukhalenko. - 2nd ed., Revised. and add. - M .: Nedra, 1990 .-- 559 p .: silt, p. 53-58.

2.1. Oilfield Equipment: Directory. / Ed. E.I. Bukhalenko. - 2nd ed., Revised. and add. - M .: Nedra, 1990 .-- 559 p.: Silt, pp. 113-137.

Claims (1)

Installation for oil production, containing a submersible electric pump unit that combines an electric motor with hydraulic protection, a pump and a cable line, lowered into the well by lifting tubing, wellhead equipment, a control station and a transformer, characterized in that in the lower part of the installation through a threaded nipple an electrode insulated from the installation casing and production casing is installed and is connected via an additional cable to the positive pole of the DC source (cathodic shields) installed on the earth's surface, the negative pole of which is connected to the wellhead.