Progress and direction of geological modeling for deep and ultra-deep carbonate reservoirs

Exploration and development of deep and ultra-deep carbonate reservoirs have been a hot and key research topic in the industry. Accurately depicting the spatial distribution and physical property parameters of the reservoirs has been a major challenge for an efficient oil and gas exploration and development. Based on an analysis of current development of reservoir geological analysis, logging evaluation, seismic prediction, geological modeling and other related technologies, this study is focused on figuring out the development mechanisms and distribution patterns of highquality deep carbonate reservoirs by overcoming the data issues (scarcity, low quality and inaccuracy) and the high heterogeneity nature of the reservoir. A series of key technologies for characterization and modelling of the deep carbonate reservoirs have been developed, including technologies for construction of multi-scale and multi-attribute deep carbonate reservoir knowledge base;new technologies for geological analysis such as macroscopic to microscopic geological observation, in-situ micro-area qualitative and quantitative analysis for reservoir sedimentation and diagenetic environment, experiment and numerical simulation technologies for mechanism and process of reservoir development;new logging interpretation technologies, such as reservoir type identification and quantitative parameter evaluation based on global logging simulation, and sedimentary microfacies identification based on machine learning;new seismic prediction methods, such as seismic petrophysical modeling, machine learning technologies for rock physics guided reservoir parameter prediction and uncertainty evaluation;new geological modeling technologies such as new algorithm of multipoint geostatistics, geological process simulation, and geological modeling based on artificial intelligence. The technological processes of geological modeling of carbonate reservoirs under the control of karst unconformity, fault and sedimentary facies have been established respectively and applied to oil and gas reservoirs in Tahe, Shunbei and Yuanba blocks in the Tarim Basin and the Sichuan Basin, providing scientific basis for exploration and development deployment. The future research direction of geological modeling for deep and ultra-deep carbonate reservoirs is also predicted: updating geological knowledge base to support geological modeling;expanding the modeling technology based on geological process and improving its application;developing geophysical interpretation and prediction technologies based on artificial intelligence to improve the ability to depict complex reservoirs;developing new modeling methods based on artificial intelligence to continuously improve the accuracy of reservoir characterization and the reliability of models;and establishing rapid updating technology of geological models for deep reservoirs to continuously improve the efficiency and accuracy of model updating.