PROCEDURE FOR STRENGTHENING UNSTABLE ROCK DURING DRILLING MAINLY INCLINED AND HORIZONTAL HOLES Russian patent published in 2011 - IPC C09K8/28 E21B33/10 

FIELD: gas and oil production.

SUBSTANCE: unstable interval of reservoir in hole is opened by means of drilling equipment with inhibited polymer drilling mud on water base. Further, there is pumped water-repellent composition with the following component contents, wt %: hydrocarbon product 10.0-60.0; tall oil or a product of its processing 1.0-3.0, amine-containing emulsifier of reverse emulsions 1.0-3.0, the said inhibited polymer drilling mud - the rest. A bath out of composition is set in an interval of the unstable reservoir for a period of not less, than 0.5 hour. Further, during drilling water-repellent composition having been used in form of the bath is transited into drilling agent by circulation.

EFFECT: raised degree of strengthening unstable rock due to its maximal hydrophobisation and mudding by forming water repellent barrier in kind of layer of reverse emulsion in near-borehole zone of well upon reservoir opening; water-repellent barrier further prevents rock contact with disperse water medium of drill agent thus facilitating complex of structure-mechanical properties of said layer at following drilling.

6 cl, 1 tbl