DEVELOPMENT METHOD OF BOTTOM-HOLE ZONE Russian patent published in 2014 - IPC E21B43/27 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry. Method of bottom-hole zone treatment includes running-in of pipe string with packer to perforated interval, washing of the well equipped with master and casing valves, packer seating above the formation and treatment of the well by pumping of hydrochloric acid solution through the pipe string in pulsed mode, process exposure for reaction and extraction of reaction products. Optimal intake of the formation is set before treatment of bottom-hole zone. Then the pipe string at the well mouth below packer is equipped with impulse liquid pulsator, at that a valve is mounted between the packer and liquid pulsator. The pipe string is run-in into the well so that packer is located above the formation, thereafter with open master and casing valves the well is flushed by straight ring circulation during 10-20 minutes. The casing valve is closed and process liquid is pumped into the formation under pressure that does not exceed permitted pressure to the production string during 5-10 minutes. The casing valve is closed and process liquid is drained from the well. Washing and drainage of process liquid is repeated 3-5 times. Then hydrocarbon solvent is pumped to the pipe string, the packer is seated, hydrocarbon solvent is pressed into the formation by process fluid under pressure not exceeding permitted pressure to the formation; the well is subjected to process exposure. When process exposure is completed the valve is actuated, liquid pulsator is cut off, the packer is released, the pipe string is run-in additionally so that radial openings of the valve are located opposite the formation; and then the well is washed out by process liquid at open master and casing valves by straight ring circulation during 2 hours. At that casing valve is closed partially periodically till bottom hole pressure increases per 3-5 MPa in comparison with the initial pressure value transparent liquid appears; at that permitted pressure for production string is not exceeded. Thereafter hydrochloride acid solution and acid-clay cut mud heated up to temperature of 40-50°C is pumped to the pipe string, the packer is seated, hydrochloride acid solution and acid-clay cut mud are pressed to the formation by process liquid under pressure that does not exceed permitted pressure on formation, the packer is released and the well remains under exposure, then by return ring circulation reaction products are washed out till transparent liquid appears, hereupon actual intake of the formation is defined.

EFFECT: increasing efficiency of bottom-hole zone treatment due to increase of bottom-hole zone intake with simultaneous simplification of process and reduction of treatment costs and duration.

5 dwg