Publications

For a well in Indonesia, a completion packer was set above top of cement in a 3 ½ in monobore production string. Following the Operator’s operating procedure, the packer was pressure tested after the cement placement. Three days after the cementing job, the packer was tested again. These tests contributed to damage the cement sheath integrity, including the generation of a microannulus. This was validated by cement stress analysis. This analysis evaluates the stresses applied to the cement sheath, and the result showed a failure in traction and the existence of a microannulus due to these pressure tests. With packer failure, the flow paths that are created could cause the hydrocarbons to migrate to the surface or to be trapped below the wellhead, leading to a pressure buildup. Therefore, self-healing cement was proposed to fill the gap and give a contingency barrier to the well integrity. This self-healing cement system is based on a responsive material with intrinsic self-healing properties automatically activated upon hydrocarbon exposure that rapidly seals the hydrocarbon path. The system has properties equivalent to conventional cement systems and requires no modifications to standard surface equipment. Within hours, the downhole well integrity is restored, thereby reducing the health, safety, and environmental risks plus the extra costs associated with remediation of these problems, including loss of production. The self-healing cement system was successfully pumped in the 3 ½ in monobore production string. This was the first application of self-healing cement in Indonesia, and it was successful in achieving zonal isolation, even in the case of a packer failure and cement sheath traction failure due to pressure tests performed on the well after the cement had set.