WELL COMPLETION METHOD Russian patent published in 2006 - IPC E21B21/14 C09K8/04 

FIELD: mining, particularly well completion means and productive reservoir penetration.

SUBSTANCE: method for exposing productive reservoir with the use of optimal complex well drilling technique in oil field at later operation stage involves limiting drilling rig lowering speed up to 0.7 m/sec; limiting axial load and mechanical drilling speed; minimizing runs due to usage of highly-productive bits without water-jet heads along with minimum acceptable shush pump capacities; performing well flushing during drilling equipment lowering at every 500 m depth. Drilling mud comprises carboxymethyl cellulose in amount of 0.5-1.0% by weight, surfactant in amount of 0.01-0.03% by weight, mineral salt in amount of 0.2-0.7% by weight, chalk in amount of 15.0-30.0% by weight, alkali in amount of 0.05-0.1% by weight, condensed spent sulfite-alcohol liquor in amount of 0.5-0.9% by weight and flotation reagent in amount of 0.1-1.0% by weight, remainder is water. The drilling mud may also have powder clay taken in amount of 5.0-7.0% by weight.

EFFECT: reduced bottom zone mudding and increased efficiency of following productive bed treatment with hydrochloric acid due to increased fullness of chalk solution in productive reservoirs, reduced hydrochloric acid consumption.

2 cl, 4 ex, 2 tbl