FIELD: oil and gas industry.
SUBSTANCE: method includes mounting in the well of a pump unit consisting of flow column, driven centrifugal pump and reciprocating pump, a cable feeding the electric drive of the centrifugal pump from the ground control station, a packer with cable entry separating strata in a certain interval of the well, and submersible telemetry systems related by a cable with the control station. When mounting is complete, the above pumps are started simultaneously or separately in order to pump out fluid from strata through the flow column to the well surface with potential recording of their flow rates at the control station. Depending on volume of gas extracted by the lower stratum of the well fluid pumping out by the centrifugal pump is made either by direct flow through the flow column or through a nozzle of liquid jet ejector installed downstream the reciprocating pump with potential gas cap releasing from below-packer annulus cavity of the well; to this end turbulent fluid flow at output of the centrifugal pump is transferred to laminar flow. When fluid pressure drops at output of the centrifugal pump and/or power consumed by the pump is exceeded, then underground washing of the centrifugal pump is made. To this end the reciprocating pump and liquid jet ejector are removed from the pump unit by the installation tool and a bypass unit consisting of coaxial pipes with communicating radial channels is installed instead of the ejector. Then from the well mouth along the flow column through coaxial cavity and radial channels of the bypass unit washing fluid is pumped to below-packer annulus cavity of the well; the centrifugal pump is washed under pressure of washing fluid through input module and the used fluid from the latter is directed under remaining pressure through coaxial cavity and radial channels of the bypass unit to the well moth though below-packer annulus cavity of the well. Upon completed washing of the centrifugal pump the bypass unit is dismounted and liquid jet ejector and reciprocating pump are installed at its place, then pumping of the fluid from strata to the well surface is continued.
EFFECT: reduced labour costs for maintenance of the well.
2 cl, 3 dwg
