METHOD FOR DRILLING A WELL WITH AN EXPOSED RESERVOIR Russian patent published in 2022 - IPC E21B21/08 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, in particular to methods for the primary opening of productive formations by wells with flushing at variable pressure. The method includes drilling a well and exposing the exposed formation to "depression" and "repression" modes. The modes of "depression" and "repression" on the formation are carried out when drilling is stopped during intensive absorption by the formation of the drilling fluid used in drilling without the use of bridging agents. "Depression" is caused by lifting the drilling tool on the drill string to reduce the liquid level, and "repression" - by lowering the drilling tool on the drill string after the liquid level is restored and adding liquid to the well to raise the liquid level above at least 50 m, after which the modes "Depressions" and "repressions" are repeated in a similar way until the onset of the "saturation mode", the decrease in fluid absorption by the formation to values that are acceptable for continuing drilling. Periodically, the impact on the exposed formation by the modes of "depression" and "repression" is repeated after increasing the injectivity of this formation until the intensive absorption of the boron solution, which excludes the effective washing out of the rock destroyed by the bit to the surface.

EFFECT: deepening is provided by drilling the wellbore without clogging the opened productive formation, time costs are reduced.

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