METHOD FOR DEVELOPMENT OF MULTI-HOLE BRANCHED HORIZONTAL WELL Russian patent published in 2016 - IPC E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry. Development method of multi-hole branched horizontal wells involves separate development of each branched shaft drilled from the main horizontal part of the well using the tubing string with packer and swab limiter arranged in lower part of vertical section of tubing string, packer seating and acid treatment of branched shaft, pumping of 10-15% solution of hydrochloric acid with further process exposure for reaction with further development of well swabbing cycles. In the well first coil tubing is run, equipped from below with hydraulic whipstock with jet nozzle at the end of the separate acid treatment for each members shaft starting from the middle to the well head, the flexible pipe string with hydraulic whipstock and jet nozzle is lowered in branched well bore up to the thrust of jet nozzle in the bottomhole of branched shaft. Then at open casing valve acid pumping is started with simultaneous rise of flexible pipe string of branched shaft without bringing 3 m to inlet of branched shaft from the main part of horizontal well at rate providing continuous replacement of the entire volume of branched shaft by acid. After filling of branched shaft with acid at closed annular valve the acid is flushed by process fluid of through hydraulic whipstock and jet nozzle from branched shaft into formation. Now, a string of flexible pipes and hydraulic whipstock with jet nozzle are removed from branched well shaft to main horizontal part of the well and process is exposed for reaction. Similarly remaining branched wellbores are processed. After acid treatment of all branched boreholes string of flexible pipes with hydraulic whipstock and jet nozzle are removed from the well and tubing string with swab limiter and inflatable packer on lower end is lowered into well following with alternating individual development of each branched borehole starting from the most remote from the wellhead. Inflatable packer is set in the main horizontal part of the well with arrangement of lower end of the tubing string opposite the inlet of quick branched shaft, and development of each branched shaft is made by swabbing cycles via the tubing string in the volume of main horizontal part of the well from bottomhole to the inlet into the branched shaft plus two volumes of developed branched shaft.

EFFECT: higher efficiency of acid treatment, quality of development of contaminated productive formation, reliability.

1 cl, 2 dwg