Cement-Sheath Integrity in Marcellus Shale Play

The Marcellus Shale Play poses complex problems for operators seeking successful productivity in an unpredictable field, but a recent article discussing a possible increase in cement-sheath integrity highlights an unexpected result discovered by CSI Technologies researchers and their colleagues.

Published in the May edition of the Society for Petroleum Engineers Journal of Petroleum Technology, the article comprises information gleaned from a paper presented at the 2014 SPE Hydraulic Fracturing Technology Conference.

In the end, the results of the research, which focus on applied energy and energy resistance, revealed a correlation between the mechanical properties of cement and the ability of that cement to provide adequate zonal isolation. In this study, one cement system had a much lower success rate than the other cement system, both applied to the intermediate casing string.

Because the intermediate casings in the Marcellus Shale are set in straight hole and at relatively shallow depth using similar mixing and placement issues, no short-term zonal isolation issues were expected.

However, loss of zonal isolation after drilling and completion processes pointed to mechanical cement-seal damage that would result in the creation of flow paths.

Resolving this issue would require extensive testing revolving around post-cementing operations, which included analysis of the energy resistance of the cement system in place. In the accompanying picture, a cement sample is hooked up to strain gauges and an industrial tester to measure its mechanical properties.

To read the full article and the results of the test, visit http://www.spe.org/jpt/.