The overall objective of this project is to determine the properties that affect cement's capability to produce a fluid-tight seal in an annulus. The project primarily focuses on deepwater applications, but general (shallow) applications were also examined. The research focuses on the measurement and correlation of cement's mechanical properties to the cement's performance. Also, research was conducted to determine which laboratory methods should be used to establish the cement's key properties. Finally, a method of quantifying laboratory test results and scaling them to field conditions was developed. This method, contained in a spread sheet, can be used to estimate cement seal performance in actual well operations. The below-attached summary of reports includes a summary of all results obtained throughout the project as well as copies of all previous reports (6-reports).
The data from this project were used to create a method of estimating a particular cement composition's ability to maintain annular seal under conditions of actual well operation. This method of scale-up from laboratory mechanical property and performance data to estimation of full scale performance is presented in attached spreadsheet MMS PH 1 - Energy Analysis.xls. The results of the Annular Seal testing were analyzed by utilizing an energy approach, in which the energy applied to the pipe / cement / formation system constitutes the mechanism of failure. Resisting the applied energy are the mechanical properties of pipe, cement, and formation, operating as a system. This methodology is essentially a macro approach, intended to eventually understand the relative effects of both production heat up as well as pressure application on the integrity of the cement sheath. By analyzing the data in terms of energy applied to the system verses the cement's mechanical properties and ability to resist seal failure, disparate forms of energy application and their effects on cement/steel seal can be correlated and understood.
The project has been completed.