US 9,809,738 B2
Microbial-enhanced well cementing and remediation
Karen Luke, Calgary (CA); and Duane Brownlee, Calgary (CA)
Assigned to Trican Well Service Ltd., Calgary (CA)
Filed by TRICAN WELL SERVICE LTD., Calgary (CA)
Filed on Nov. 7, 2014, as Appl. No. 14/536,430.
Claims priority of application No. 2832791 (CA), filed on Nov. 7, 2013.
Prior Publication US 2015/0122486 A1, May 7, 2015
Int. Cl. E21B 33/13 (2006.01); C09K 8/467 (2006.01); C09K 8/42 (2006.01); C04B 28/02 (2006.01)
CPC C09K 8/467 (2013.01) [C04B 28/02 (2013.01); C09K 8/428 (2013.01); E21B 33/13 (2013.01)] 19 Claims
 
1. A method of cementing a wellbore comprising:
a) preparing a cement composition comprising a pumpable slurry of cement, water and a healing agent that comprises Bacillus pseudofirmus that is tolerant to pressure of 98 atm (10 MPa) and 20° C.;
b) delivering the cement composition into the wellbore; and
c) allowing the cement composition to set,
wherein the wellbore has a downhole pressure of 1 atm-1000 atm (0.1-100 MPa); andwherein when the integrity of the set cement composition is breached, activating the Bacillus pseudofirmus in the set cement thereby causing them to grow and replicate at a pressure of at least 98 atm (10 MPa) to thereby restore the integrity of the set cement composition.