Fluid loss control agents and compositions for cementing oil and gas wells comprising said fluid loss control agent

摘要

A method of cementing a well is disclosed. The method comprising pumping into the well a cement slurry comprising a solid blend including cement, water, and a fluid loss control agent, and allowing the cement slurry to set. The fluid loss control agent comprises a styrene-butadiene latex and a high molecular-weight water-soluble polymer such as a copolymer AMPS-Am. The addition of the water-soluble polymer allows drastic reduction of the quantity of latex required to achieve fluid loss control performance and even gas migration control.

主权项

1. A method of cementing a well, comprising:
(i) preparing a fluid-loss control agent consisting of a single mixture of a styrene-butadiene latex and an unhydrolyzed water-soluble polymer having a molecular weight between 200,000 and 4,000,000; (ii) adding the fluid loss control agent to a cement slurry comprising cement and water; and (iii) placing the slurry in the well.