BSEE Concludes Study on Testing Seal Viability of Cement Plugs
BSEE recently concluded a study performed by CSI Technologies of Houston, Texas to assess its current regulations related to testing cement plugs used to permanently or temporarily abandon offshore oil and gas wells.
The basis for this project was to establish a best practice for evaluating cement plug seals for well abandonment, built on a comprehensive engineering study of the fundamentals governing cement plug seal performance. It assessed the necessary attributes of the seal formed by a cement plug, and determined the effects of wellbore geometry, cement properties, and placement methods on these attributes. Bond and seal effectiveness determined by current plug evaluation methods described by BSEE’s regulations (pressure testing and weight testing) were evaluated to identify potential leak pathways and failure mechanisms. Through this study, CSI Technologies found that the current requirements were not a sufficient way to test the viability of a cement plug seal between well zones. They were able to identify an optimum verification method for the cement plug seal, as well as a correlation to relating well geometry, cement properties, and placement methods for forming an effective seal. CSI Technologies also provided recommendations for future work, which could potentially help improve the way intermediate plugs are tested.
The final report has been made available for download through BSEE’s website at http://www.bsee.gov/Research-and-Training/Technology-Assessment-and-Research/Project-680.aspx