Modelling of wellbore integrity in CO2 storage sites
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Modelling of wellbore integrity in CO2 storage sites
Mon, 16/09/2019 - 14:45 to 15:15
Location:
Speaker:
Mohammadreza Bagheri
Affiliation:
Centre for Fluid and Complex Systems, Coventry University
Synopsis:
In CO2 storage sites, the defects in the cement sheaths of drilled wells endanger the effectiveness of carbon capture and storage projects. The wells in CO2 storage sites are direct connections between the underground formations and the Earth’s surface. The cement sheath acts as a barrier preventing the permeation of CO2-bearing fluids to the surrounding and inside of the well casing. However, the movement of injected CO2 from injection wells brings an acidic environment into contact with the cement sheath. The performance of cement sheath is affected by the invasion of CO2-bearing fluids. Its durability can be compromised due to the degradation process and the stress state resulted from the conditions found underground. The integrity of cement sheath is a function the cement composition, rock type, fluid pressure, stress state, temperature, and the type of wells. This work presents a methodology to investigate the stability of rock-cement-casing assemblage. The mechanical behaviour of the rock-cement-casing assemblage is coupled with the chemical alterations occurring in this assemblage during the invasion of CO2-bearing fluids. A plasticity approach is also introduced to characterise the performance of cement matrix being affected by both of failure and deformation within in altered regions.
Biography:
Mohammadreza Bagheri- Mohammadreza completed his BSc in petroleum engineering at Sharif University of Technology. His B.Sc. project was entitled: Geostatistical Analysis of Well Log Data to Characterise Structural and Reservoir Heterogeneity. The reason behind choosing this title was the idea that a majority of uncertainties in the final reservoir model originated from the reservoir characterization.
He attended the University of Tehran to study his MSc in hydrocarbon reservoir engineering. His interest in reservoir simulation led him to the reservoir characterization field. He chose 'Characterization of Reservoir Rock Heterogeneity and Distribution of Fluid Flow Properties Using Fractal Geometry' as his M.Sc. project. The main focus of this project was the static simulation of reservoirs using fractals. It is worth noting that the static simulation is one of the very first steps which is needed in the reservoir engineering.
Now, as a PhD student at Coventry University, he is working on the characterization of the behaviour of well cements exposed to CO2-bearing fluids. The prediction of CO2 leakage through well cements is crucial, especially when depleted oil and gas reservoirs are selected for CCS projects.