LIGHTENED CEMENTING SOLUTION, CEMENTING SOLUTION FOR PRODUCTIVE ZONE OF WELL AND METHOD FOR CEMENTING WELLS Russian patent published in 2005 - IPC

FIELD: oil and gas industry.

SUBSTANCE: lightened cementing solution has Portland cement, lightening admixture, aluminum oxychloride and water, as lightening admixture has admixture from the group: clay, Tripoli powder, diatomite, vermiculite, perlite, and as aluminum oxychloride has at least one compound from the group: aluminum hydrooxychloride, aluminum pentaoxychloride, aluminum tetraoxychloride with following ratio of components in portions of mass: Portland cement - 100, said lightening admixture - 5-10, said aluminum oxychloride - 0.05-1, water - until receiving water-cement relation - 0.6-1.4. Cementing solution for productive well zone has Portland cement, aluminum oxychloride and water, as aluminum oxychloride has at least one compound from the group: aluminum hydrooxychloride, aluminum pentaoxychloride, aluminum tetraoxychloride, and, additionally, water-loss decreasing substance and antifoaming additive, with following ratio of components in portions of mass: Portland cement - 100, said aluminum oxychloride - 0.05-4, water loss decreasing substance - 0.2-0.6, antifoaming additive - 0.02-0.06, water - until receiving water-cement relation 0.45-0.50, while said cementing solution can additionally contain accelerator and/or plasticizer in amounts 0.04-0.6 portions of mass each. Method for cementing wells includes washing with buffer solution with following feeding of cementing solution, after washing by buffer solution serial feeding of condensed pack of cementing solution is performed - metal silicate, said lightened cementing solution, and then said cementing solution for productive well zone. Cementing solution for productive well zone can additionally contain accelerator and/or plasticizer in amounts 0.04-0.6 portions of mass of each.

EFFECT: full filling and reliable engagement of stone with rock and casing string.

3 cl, 11ex, 2 tbl