A Quantitative Assessment of Atmospherically generated Foam Cements: Insights, Impacts, and Implications of Wellbore Integrity and Stability.

The primary function of well cement is to provide casing support and zonal isolation for the life of a well (Thiercelin et al., 1998; Singamshetty, 2004; Iverson et al., 2008). Failure to achieve one or both of these conditions can lead to a migration of fluids up the wellbore and result in both economic and ecological disasters, as exemplified by the Deepwater Horizon oil spill on April 20, 2010. To avoid these kinds of failures, the cement must have sufficient strength to secure the casing in the hole and withstand the stresses of drilling, perforating, enhanced oil recovery, and hydraulic fracturing and also be able to keep the annulus sealed against the formation. This thesis analyzes and presents in detail some of the mechanical and physical properties of atmospherically generated foamed cements typically used in deep offshore wells in the Gulf of Mexico. Both static and dynamic measurements were taken across a range of foam qualities and include permeability, porosity, compressive strength, Young’s modulus (E), and Poisson’s ratio (ν). Investigating the properties of a range of foam qualities and cement recipes provides better understanding of the effect that different amounts of entrained air can have on cement performance and reliability. To better represent the behavior of cements in the wellbore, we subjected cements to pressure cycling and the measurements were analyzed over the range of these pressures. Our results show how these foamed cements behave and will prove to be a good baseline for future testing on cements generated under in-situ conditions.