CEMENTING METHOD FOR PRODUCTION STRING OF GAS WELL DRILLED IN PERMAFROST GROUND Russian patent published in 2006 - IPC E21B33/13 C09K8/473 

FIELD: oil production industry, particularly to develop and exploit deposits in permafrost territories.

SUBSTANCE: method involves injecting buffer liquid and plugging composition in tubing space; forcing thereof with displacement liquid, wherein the displacement liquid is three-phase foam. Light-weight plugging composition is injected in well before main plugging composition injection. The light-weight plugging composition comprises filler, namely gas-filled microspheres. Suspension including nonfreezing liquid having density exceeding mix liquid of above light-weight plugging composition and gas-filled microspheres treated with lanoline acids taken in amount of 0.1-0.4% of total gas-filled microsphere mass, is supplied to tubing space before light-weight plugging composition injection. Nonfreezing liquid volume and total microsphere mass are calculated from formulas. The plugging composition volume is selected to provide well filling for depth from well bottom to productive formation roof. The suspension volume is enough to fill hole annuity between well head and permafrost rock bottom. Light-weight plugging composition is taken in amount, which provides hole annuity filling from productive formation roof to permafrost rock bottom. The gas-filled microspheres are formed of glass or silica-alumina or polymeric material.

EFFECT: increased efficiency of well cementing.

2 cl, 1 ex, 1 tbl