FIELD: oil and gas industry.
SUBSTANCE: group of inventions relates to drilling and exploration of hydrocarbons. Method of pressure control in underground borehole includes preparation of buffer, transmitting fluid pressure (FPTP), mixing of composition containing oily liquid, organophilic clay and polar activator, as long as composition does not form gel-clay, introduction of FPTP buffer into well, while the first oil-based drilling mud is in the well, introduction of the second fluid with high density into the well on the upper surface of the buffer FPTP to achieve excessive total hydrostatic pressure in the well. FPTP buffer isolates the first drilling fluid from the second fluid.
EFFECT: higher efficiency of pressure control in wells during downhole operations, logging and other underground operations.
18 cl, 12 dwg, 1 tbl
