WELL CONSTRUCTION METHOD Russian patent published in 2020 - IPC E21B7/00 E21B43/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used in secondary wells opening. Method includes drilling a well in a productive formation along an ascending or descending trajectory of a shaft, lowering and cementing a production string, preliminary determination of physical and rheological parameters of the fluid in formation conditions with due allowance for its composition, secondary penetration of formation with different density of perforation providing for uniform distribution of pressure drop along whole length of ascending or descending section of well between formation and borehole space. Ascending or descending endings of the shafts in the productive formation are drilled at an angle which excludes local descending or ascending areas for corresponding ends of the shafts. Production string is installed for the whole length of the well with further casing, and the well is used as the injection well. Perforation is performed after well casing by means of perforators or without perforator method taking into account selected suction or injection interval in ascending or descending borehole. Suction or delivery interval in the ascending or descending end of the well bore is preferable to be located in the zone of the formation with the least permeability.

EFFECT: enlarging functional capabilities due to implementation and in injection wells, achieving intensification of production of formation fluid and injectivity of working agent at secondary opening of wells by perforation to increase oil recovery factor or gas recovery factor.

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