BOTTOMHOLE ZONE TREATMENT METHOD FOR HORIZONTAL WELL Russian patent published in 2014 - IPC E21B43/27 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: bottomhole zone treatment method for a horizontal well includes running-in into the treated bottomhole zone of a hydroperforator with a one-way acting pipe string with nozzles faced upwards, impact of hydrocarbon solvent jet through it, then impact by acid solution, process withhold for reaction with acid, running-out of the equipment from the well, swabbing and bringing the well into production. Before running-in, at the head of a horizontal well, the lower end of the pipe string is equipped bottom upwards with a centralising tube, the one-way acting hydroperforator with nozzles faced upwards, a pulsed liquid pulsator, a valve consisting of a saddle and body with openings covered tightly by the saddle fixed by a shear pin in regards to the body, the pipe string is run in into the bottomhole of a horizontal well until it backs the centralising tube. Then in pulse mode, in two stages, the bottomhole zone is impacted through the hydroperforator at first by a hydrocarbon solution jet, then by a jet of hydrochloric acid. While implementing two stages with simultaneous injection of hydrocarbon solvent or hydrochloric acid the pipe string is moved from the bottomhole to the head at constant speed along the length of the horizontal well screen. When injection of hydrochloric acid is completed the hydroperforator is placed at the well screen end from the well head side, then a plug is set at the head to the pipe string and flushed by process liquid through the pipes till it sets at the valve saddle and the shear pin is destroyed under pressure in the pipe string. Then the process is withhold during 1 hour, at that in process of this withhold the pipe string is run in until the hydroperforator rests in the bottomhole of a horizontal well. Then, during three cycles, 0.5 m³ of process liquid is injected to the pipe string and tubing-casing annulus in turn. When withhold time is over reaction products are washed out by return circulation in one and a halve volume of the well.

EFFECT: effective treatment for bottomhole zone of a horizontal well due to expansion of the stratum area treatment, exclusion of the well screen clogging, reduction of the process duration when this method is implemented.

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