METHOD OF DRILLING FORMATIONS WITH ABNORMALLY HIGH FORMATION PRESSURE AND PREVENTING COLLAPSED WELL CASING STRING DURING OPERATION THEREOF Russian patent published in 2020 - IPC E21B21/08 

FIELD: drilling of soil or rocks; mining.

SUBSTANCE: invention relates to oil and gas industry, in particular, to drilling, construction and operation of wells at gas-condensate fields in the presence of formations with abnormally high formation pressure (AHFP). Method comprises preliminary drilling and construction of additional absorbing well. Drilling, casing and attachment of production well shaft is carried out to the roof of high-pressure water-bearing formation with AHFP with thermostating of column by creation in formed closed annular space between conductor and intermediate column of vacuum due to injection process by means of jet pump located in wellhead, as working agent for which well production is used. Performing drilling and controlled removal of formation water from high-pressure formation into absorption well due to formation energy till AHFP is reduced. Then drilling and well construction on hydrocarbon producing horizons are completed with inclusion of two sections into casing production string: opposite to high-pressure water-saturated formation and productive horizon to gas, made with perforated casing with holes, plugged with cut plugs. Perform simultaneous separate operation of high-pressure and gas-condensate horizons by equipping the well with downhole equipment, which involves lifting of formation water to day surface with downhole gas lift, their removal to the absorption well through the unit for extraction of valuable components.

EFFECT: provides for accident-free penetration of strata with AHFP, prevention of crash of well casing string during its operation at gas-condensate multilayer deposits and improvement of efficiency of deposit development due to integrated development of formation fluid.

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