Cement composition containing an additive of a pozzolan and a strength retrogression inhibitor

A method of cementing in a subterranean formation comprising:

• introducing a cement composition into the subterranean formation, wherein the cement composition comprises:
• cement;
• water;
• and
• an additive, wherein the additive is a pozzolan and a strength-retrogression inhibitor, and wherein a mixture consisting essentially of:
• the additive;
• water;
• and a source of calcium develops a compressive strength of at least 500 psi (3.4 MPa) at a time of 24 hours, a temperature of 190° F. (88° C.), and a pressure of 3,000 psi (20.7 MPa),
• wherein a test cement composition consisting essentially of:
• the cement;
• the water;
• and the additive, and in the same proportions as in the cement composition develops a compressive strength of at least 1,800 psi (12.4 MPa) when tested at 24 hours, a temperature of 190° F. (88° C.), and a pressure of 3,000 psi (20.7 MPa), and wherein the compressive strength of the test cement composition at a final time of 72 hours has a percent change greater than −5% from the compressive strength of the test cement composition at an initial time of 24 hours when tested at a temperature of 300° F. (149° C.) and a pressure of 3,000 psi (20.7 MPa);
• and
• allowing the cement composition to set, wherein the step of allowing is performed after the step of introducing.

A cement composition comprising:

• cement;
• water;
• and
• an additive, wherein the additive is a pozzolan and a strength-retrogression inhibitor, and wherein a mixture consisting essentially of:
• the additive;
• water;
• and a source of calcium develops a compressive strength of at least 500 psi (3.4 MPa) at a time of 24 hours, a temperature of 190° F. (88° C.), and a pressure of 3,000 psi (20.7 MPa).