METHOD OF FORMATION TREATMENT Russian patent published in 2014 - IPC E21B43/25 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and may be used for treatment in wellbottom zone. Method of formation treatment includes running-in of pipe string with packer to perforated interval. The well equipped with master and casing valves is flushed. Packer is seated above the stratum, thereafter the well is treated by acid solution pumping through the pipe string in pulsed mode. Before treatment the optimal intake is set for formation. 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 the well is flushed with process liquid at open master and casing valves by straight ring circulation during 1 hour. Then process liquid circulation is continued; periodically casing valve is closed until bottomhole pressure increases per 3-5 MPa in comparison with initial pressure with subsequent opening of the casing valve till transparent liquid appears. At that permitted pressure for production string is not exceeded. Thereafter ring circulation is continued within half an hour. 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 packer is released and the well remains under exposure. Then acid-clay cut mud heated up to temperature of 40-50°C is pumped to the pipe string, the packer is seated, acid-clay cut mud is pressed to the formation by process fluid under pressure that does not exceed permitted pressure on formation. The packer is released and the well remains under exposure. After exposure period the valve is actuated and impulse liquid pulsator is cutoff. Then the packer is released, the pipe string is run-in so that radial openings of the valve are located opposite the formation and by reverse ring circulation reaction products are washed out during 1 hour. Thereafter the master valve is closed and process fluid is pumped to the formation though annulus and actual intake value is determined for the formation.

EFFECT: improving efficiency of bottom-hole area treatment and simplifying process of the method implementation.

3 dwg, 1 ex