METHOD OF DETERMINING AIR-TIGHTNESS OF DOWNHOLE EQUIPMENT WITH DUAL EXTRACTION OF FLUIDS FROM WELL WITH SUCKER-ROD AND ELECTRIC-CENTRIFUGAL PUMP

摘要

FIELD: oil and gas industry.;SUBSTANCE: invention can be used in dual operation of production wells. When determining air-tightness of downhole equipment with dual extraction of fluids from well with sucker-rod pump and electric-centrifugal pump, dynamic level is determined in annular space of upper site, dynamometer chart of sucker-rod pump is measured. Further, method includes measuring operation parameters of electric centrifugal pump with telemetric system, collecting a control sample of fluid from flow line for water content, making sure of good condition and tightness of wellhead equipment, stopping sucker-rod pump of upper site. Then both in lower and upper position of ground drive of sucker-rod pump, performing pressurisation of tubing string with help of electric centrifugal pump of lower site while tracking change of pressure in buffer when operating with a closed valve. After stopping electric centrifugal pump, monitoring readings of operation at control station, in presence of alarm signal "turbine rotation", making a conclusion on drainage of liquid from tubing string and leakiness of check valve of electric centrifugal pump. At identical rate of rise and drop of temperature on buffer of well in different positions of ground drive of sucker-rod pump and pressure drop rate within a range of not more than 2 MPa for 15 minutes, making a conclusion on tightness of switch and tubing string in range of electric centrifugal pump to well head. At rate of increase of pressure on buffer of well in upper position of ground drive of sucker-rod pump below and rate of drop higher than in lower position of drive of sucker-rod pump, making a conclusion of leakage of sealing cup in lock support of switch. If in upper position of ground drive of sucker-rod pump electric centrifugal pump does not develop pressure at well buffer, and in lower develops and there is lifting of liquid level in annular space, then conclusion is made on output of sealing cup of sucker-rod pump from lock support switch. If both in both lower and upper position of ground drive of sucker-rod pump rate of pressure drop on buffer is more 2 MPa for 15 minutes, then conclusion is made on leakage of switch and/or tubing string in range of electric centrifugal pump to well head. Sucker-rod pump and electric-centrifugal pump are then put into operation without stopping sucker-rod pump of upper site, stopping operation of electric centrifugal pump of lower site. Immediately after shutdown of electric centrifugal pump of lower site, fluid level in annulus is monitored, and pressure change is measured periodically under packer based on readings of telemetric system on display panel of controller of control station. At stable increasing in level of liquid, conclusion is made on leakage, and at constant level of liquid, conclusion is made on tightness of packer or section of tubing string from electric centrifugal pump to packer.;EFFECT: determination of tightness of downhole equipment.;1 cl, 2 dwg