Amphoteric polymer suspending agent for use in calcium aluminate cement compositions

摘要

A cement composition for use in a well that penetrates a subterranean formation comprises: a calcium aluminate cement or calcium magnesia cement; water; a fluid loss additive; and a suspending agent, wherein the suspending agent is a polymer and wherein the polymer: (A) is amphoteric; (B) has a molecular weight greater than 100,000; and (C) does not increase the fluid loss of the cement composition greater than 15% at a temperature of 145° F. (63° C.) and a pressure differential of 1,000 psi (7 MPa) compared to a cement composition consisting of the cement, the water, and the fluid loss additive. A method of cementing in a subterranean formation comprises: introducing the cement composition into the subterranean formation; and allowing the cement composition to set.

主权项

1. A method of cementing in a subterranean formation comprising:
introducing a cement composition into the subterranean formation, wherein the cement composition comprises:
(A) a calcium aluminate cement or calcium magnesia cement;(B) water;(C) a fluid loss additive; and(D) a suspending agent, wherein the suspending agent is a polymer and wherein the polymer:
(i) is amphoteric;(ii) has a molecular weight greater than 100,000; and(iii) does not increase the fluid loss of the cement composition greater than 15% at a temperature of 145° F. and a pressure differential of 1,000 psi compared to a test cement composition consisting of the cement, the water, and the fluid loss additive and in the same proportions as the cement composition; and causing or allowing the cement composition to set after the step of introducing.