April 2023: Modeling CCS Reservoir Risks
Channel: Texas CSEE
Date: 2023-04-14

Abstract
Carbon capture and storage (CCS) is the key opportunity to reach climate change goals with more companies investing in large-scale projects. A CCS project involves CO2 capture from high-emission industries and injecting it into geological formations such as saline aquifers and depleted oil/gas reservoirs. One of the most critical barriers for long-term and large-volume CO2 storage in geological formations is the proof of safe/reliable storage and maintaining the target injectivity.  
In this talk, we highlight the main reservoir risks related to CCS and how to represent them in field-scale numerical models in order to support future projects. We will cover the CO2 trapping mechanisms in porous media and the injectivity assessment based on published laboratory and field results. These include water vaporization, dry-out effect, mineral dissolution leading to fines migration, and hydrate formation with subsequent permeability/porosity reduction. We have quantified the influence of these mechanisms on CO2 injectivity in both synthetic and real field models. 
All those mechanisms will be coupled with other phenomena involved in CCS modeling, such as CO2 solubility, hysteresis trapping, and mineralogical reactions. This integration enables the construction of models for careful evaluation of CCS projects and fills a lack of numerical studies, coupling different mechanisms observed on a laboratory scale and discussing their importance on the field scale.


Bio
Marcos Machado is a senior petroleum engineer and senior reservoir consultant from PETROBRAS, based in Rio de Janeiro, Brazil. Currently, he is spending a period of 1.5 years as a Visiting Researcher at UT, working on CCS modeling in Prof. Sepehrnoori and Prof. Delshad’s group. 
Marcos obtained his Ph.D. in Reservoir Engineering in 2009 in Brazil and has worked for PETROBRAS since 2007. He is also a Reservoir Engineering Professor in the Mechanical Engineering Department at the Pontifical Catholic University of Rio de Janeiro.