DRY MIXTURE FOR BUFFER SOLUTION Russian patent published in 2008 - IPC C09K8/40 

FIELD: chemistry, inorganic.

SUBSTANCE: invention is related to dry mixtures for production of controllable-density buffer solutions used in cementing of casing strings in petroleum, gas and other wells. The dry mixture for the buffer solution includes, % by mass: 20-35 sand, 64-79 clay activated by grinding and preliminarily burnt at a temperature of 950-1000°C, 0.5-1.0 semi-aquatic gypsum, 0.005-0.01 silicon.

EFFECT: higher sedimentation stability of the buffer solution produced from the dry mixture, broader solution density adjustment range, better compatibility of the buffer solution with drilling fluids and grouting mortars.

2 tbl, 1 ex