OIL-WELL SUCKER-ROD PUMP Russian patent published in 2001 - IPC

FIELD: oil industry; pumping oil and other liquids from wells. SUBSTANCE: pump has plunger, plunger rod, cylinder accommodating suction and delivery valves and plunger rod guide with passage posts. Plunger is made in form of blind sections arranged in tandem and sealed in cylinder. Sections are coupled with plunger rod and with each other for free displacement and deflection of section axis from plunger rod axis of other section. Plunger rod is sealed in plunger rod guide. Sand filter is installed in passage ports of plunger rod guide. Owing to such design, wear of friction surfaces of plunger and cylinder is reduced at reduced requirements to rectilinearity of cylinder. EFFECT: improved sealing and repairability of machine and operating conditions of bottom-hole assembly of drill string. 2 cl, 2 dwg