CO₂Sequestration Uncertainty Analysis, Potential Estimation And4D Seismic Monitor Feasibility Analysis Method

Carbon dioxide capture and geological sequestration (CCS) is a means of reducing greenhouse gas emissions into atmosphere. In order to avoid the high economic risk of CO2geological sequestration project, we provide a series of estimation and prediction study on sequestration site selection, which are fundamental issues for the commercial deployment of CCS. The prime focus of the selection of sequestration sites is including sequestration capacity estimation, sequestration potential evaluation and the appropriate technologies for monitoring the movement of the stored CO2. In this paper, we choose deep saline aquifer as an example and fully evaluated the uncertainty of effection factors for CO2sequestration with statistic analysis method, based on geological modeling and reservoir simulation techniques. Upon all these result, a new capacity estimation method is developed focus on little scale of site selection under the condition of exiting data absence. Otherwise, a systematic4D seismic feasibility analysis method is developed for CO2geological sequestration project, which simulate the seismic record corresponding to the movement of CO2underground.In the uncertainty analysis of CO2geological sequestration, we have some improvement, which bring time as a new factor into our analysis to the previous research results. So, we can find the master factors for the CO2sequestration results. in different injection stages. The notable interactive relationships are taken to detail analyse. And based on all these results, a regression and prediction model of CO2sequestration is built for theoretical homogeneous model, which can achieve CO2sequestration capacity estimation without simulation. All these study is mean to recognize the regularity of the relationship between different properties of reservoir and the CO2sequestration result.In practical use, we normally can get the distribution range of influencing factors. The homogeneous model can be recognized as a special situation of heterogeneous models. Then we can assume the distribution probability of the CO2sequestration simulation result in homogeneous may have some relationships with heterogeneous model. Based on this assumption, we develop a new method which show encourage result in our practical test, but the applicability of this method still need more study and further demonstration.A systematic4D seismic feasibility analysis method, which build the relations between seismic response and the results of geological modeling and reservoir simulation that indicate the CO2displacement and migrate in the underground is developed for CO2geological sequestration project. At last, a new method, which combine reservoir simulation, to predict pressure distribution and separate the effect of preesure and saturation for4D seismic interpretation is developed. For the absence of real data, only part of uncertainty is evaluated by numerical test in this thesis.