DEVICE FOR OIL RECOVERY AND TREATMENT OF WELL BOTTOM-HOLE FORMATION ZONE Russian patent published in 1999 - IPC

FIELD: oil producing industry. SUBSTANCE: device includes pump with openings in its body upper part and inlet valve, and plunger with valve installed in pump body for reciprocation. Cut-off valve is located between plunger and inlet valve. Made inside body of shutoff valve are upper and lower groups of guide projections. Located in shutoff valve is spring-loaded rod protruding above shutoff valve for contacting plunger. Rod has slots accommodating upper group of guide projections, teeth with chamfers and shoulders between teeth in lower part. Located under rod is pushing rod having, in its upper part, teeth with chamfers with opposite direction relative to chamfers of rod teeth and recesses between teeth in which lower group of guide projections are found. Lower part of pushing rod is located for vertical motion in hole of seat of shutoff valve. Located under seat on perforated plate is spring pressing ball contacting seat hole. EFFECT: provided transition from treatment of bottom-hole formation zone to oil recovery and vice versa without round trips. 2 dwg