METHOD FOR PRIMARY PRODUCTIVE BED PENETRATION FOR OIL AND GAS DRILLING Russian patent published in 2006 - IPC E21B21/00 C09K8/04 

FIELD: oil and gas production, particularly for flushing boreholes, for instance by use of exhaust air from motor.

SUBSTANCE: method involves performing mechanical well drilling with the use of aqueous fresh drilling mud to which additives are sequentially admixed. Active bentonite phase is added during mechanical drilling before productive bed penetration. Nitrilotrimethylphosphonic acid N(CH₂PO₃H₂)₃ is mixed with drilling mud after productive bed penetration and mechanical well extension operation termination. Synthetic polymeric agent, namely polyethylenoxide, is added to drilling mud after well bore reaming within productive rock interval. Then at least one well bore section is filled with chalk solution without plastering reagents.

EFFECT: provision of optimal productive bed penetration conditions.

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