The most important aspect in wellbore construction is creating and maintaining wellbore integrity and zonal isolation. The potential of freshwater contamination has captured the attention of the public and media. A crossflow between productive intervals or saltwater zones can result in environmental and legal challenges, and lost production. The number of wells developing annular pressure over time has become a concern and expense for operators. The design and placement of a competent cement seal in the annulus is critical in addressing these issues. This presentation describes how the testing has progressed from Code 32, the first API code, to the present day ISO and API guidelines. The audience should gain a better understanding of what cement is needed to do and the laboratory tests required to make sure it does.
Don Purvis is an independent technical consultant who has done extensive research on cement flow dynamics and testing methodology. He has held research, engineering, and management positions with major service companies and operators. He holds two process patents and has authored multiple technical papers and journal articles. He has given technical presentations on good cementing practices both inside and outside of the oilfield community. Purvis holds an electrical engineering degree from Oklahoma State University.