METHOD OF PRODUCING BACKFILL CEMENT SWELLING AGENT Russian patent published in 2024 - IPC C04B40/00 C04B14/08 C04B22/06 C04B28/02 C09K8/467 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of producing a swelling agent for oil well cement, which relates to the technology of additives to cement slurry of oil wells for cementing wells. Method involves grinding dolomite, calcium stearate and magnesium stearate in a ball mill to obtain material, which after mixing is mixed with diatomite. Mixed material is dried and briquetted to produce briquettes. Drying process conditions include the use of a box-type air blower at temperature of 90 °C for 12 hours. Briquetting process conditions include application of pressure of 50–65 kN, subsequent pressure increase at rate of 0.2 kN/s, then, pressure is reduced after holding under pressure for 185–200 s and pressure is maintained at ≤ 4.5 kN during depressurisation. Process of preliminary sintering of briquettes is performed with further grinding after cooling to obtain powder. Powder is subjected to high-temperature calcination and is quenched after holding at a predetermined temperature for a certain period of time to obtain a lump swelling agent. Lump swelling agent is ground in a ball mill to obtain a cement swelling agent.

EFFECT: reduced volumetric shrinkage of cement during hydration and increased interlayer sealing capacity of cement rings.

8 cl, 4 dwg, 1 tbl, 3 ex