H039-0004
Thermo Hydro Chemical Numerical Analysis of the Efficacy of Subsurface Sealing Materials
Tuesday, 8 December 2020
Poster
Ipsita Gupta, Louisiana State University, Craft & Hawkins Department of Petroleum Engineering, Baton Rouge, LA, United States and Temitope Ajayi, Louisiana State University, Craft and Hawkins Department of Petroleum Engineering, Baton Rouge, LA, United States
Abstract:
Plugged wells in offshore facilities are constantly exposed to different forms of subsurface fluids and conditions. These fluids and the conditions in which they exist vary in temperature, composition, salinity etc. The capacity of the sealing materials used in these platforms to maintain their integrity over extended time periods remains one of interest. As the impact of these fluids and conditions are more likely to affect the geochemical integrity of these materials, a thermal, hydro chemical (THC) model is developed in this study to investigate the ability and efficacy of these materials to maintain integrity. A representative brine sample of the deep Gulf of Mexico platforms is used as input to the THC model. A geological stack of different rock types is also used to investigate the impact of different rock types on the overall assessment of the sealing materials. The assessment is performed through a sequential non-iterative algorithm where flow, heat, transport and chemical processes are coupled.
Results show the importance of the sealing materials binding to the rock type. The sharp pH difference at the binding interface could provide an important consideration in the design of sealing materials. In addition, compounds such as ettringite influence significantly the decrease or increase in the pore spaces present in these sealing materials.
In conclusion, we have been able to model the impact of unfavorable offshore conditions on the geochemical integrity of sealing materials used in plugging wellbores post production. This would provide important results for material designers in ensuring more effective materials are designed capable of effective subsurface sealing.
Funding for this research is from the National Academy of Sciences, Engineering and Medicine (NASEM) Gulf Research Program (GRP) grant on “Mitigating Risks to Hydrocarbon Release through Integrative Advanced Materials for Wellbore Plugging and Remediation” under award number 200008863.
This content is solely the responsibility of the authors and does not necessarily represent the official views of the GRP or the NASEM.
