Jandhyala, Siva Rama Krishna (Halliburton) | Pangu, Ganesh (Halliburton) | Deshpande, Abhimanyu (Halliburton) | Wolterbeek, Tim (Utrecht University) | Cornelissen, Erik (Shell Global Solutions International B.V.) | van Eijden, Jip (formerly at Shell Global Solutions International B.V.)
Expansion additives have been used in cement plugs to mitigate the potential risk of plug failure resulting from shrinkage. These additives are effective only when their amount is tailored for downhole boundary conditions, and their role should be well understood. This work discusses using an improved testing method that enhances the dependability of the volume change measurement and exhibits the impact of test boundary conditions on the shrinking and expanding behaviors of cement plugs.
Boundary conditions investigated with this method include temperature, pressure, water access to the cement from the formation, and the role of mechanical constraints. Dependability is demonstrated by verifying the repeatability and reproducibility of the method at two different laboratories. Together with the noninvasive continuous volume change, supplementary measurements, such as ultrasonic compressive strength, tensile strength, and chemical composition analysis, have provided inferences about the mechanism of volume change.
The new method embodies all attributes listed in
These observations were possible because the test method can capture temporal and boundary condition effects more aptly. Thus, the improved method provides a dependable measurement for tailoring plug properties.