Deep learning for predicting water saturation using rock physics analysis and eostatistics theory: A case study of the Psh8 in GFZ area, Ordos Basin
Wang Yong-gang, Wang Ya-ting, Zhao De-yong, Cai Ke-han, Liu Wei-fang,*, and HeYu-ting
1. Exploration and Development Research Institute of PetroChina Changqing Oilfield Company, Xi’an ,Shanxi,710018,China
2. National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields,Xi’an,Shanxi,710018, China
3. GeoSoftware Technology Services(Beijing) Co.Ltd,Beijing,100015,China
Abstract Tight sandstone reservoirs have strong heterogeneity and complex gas–water relationship, causing difficulty in quantitatively predicting water saturation. Deep learning, combined with rock physics analysis and geostatistics theory, was used to predict water saturation in tight sandstone, focusing on the Psh8 in the GFZ area of the Ordos Basin. Results show that: Starting with actual wells where porosity and saturation results are obtained from log interpretations, the relationship between reservoir parameters (porosity and saturation) and elastic properties (P-wave velocity, S-wave velocity, and density) is established through the development of a rock physics model suitable for the region. Under the constraints of geostatistical laws, such as background trends of elastic and reservoir parameters and the vertical variations in logging curves, reservoir conditions (including porosity, saturation, and thickness) are simulated to generate numerous pseudowells and corresponding seismic gathers modeled using the Zoeppritz equation. A convolution neural network is used to train the target curve and predict the target body. The predicted water saturation of the Psh8 shows strong agreement with the results from two blind wells, providing a reliable basis for understanding the water saturation (Sw) of tight sandstone.
Fund: This work was Supported by : CNPC Major Project "Research on Key Technologies for Enhanced Oil Recovery in Tight Sandstone Gas Reservoirs" (No. 2023ZZ25) ; Gansu Provincial Science and Technology Major Project "Research and Application of Key Technologies for Geophysical Prediction of Natural Gas Reservoirs in Longdong Area" (No. 23ZDGA004); PetroChina Changqing Oilfi eld Company 'Qingshimao gas fi eld water-bearing gas reservoir 3D seismic fine interpretation and well position support' (No.2023QCPJ33)
About author: Correspondent: Liu Wei-fang is a senior engineer currently working at GeoSoftware Technology Services (Beijing) Co. Ltd. He graduated from the Lanzhou Branch of the Chinese Academy of Sciences with a master's degree in sedimentology in 1996. At present,he is mainly engaged in comprehensive seismic interpretation. E-mail:Weifang.liu@geosoftware.com
Cite this article:
. Deep learning for predicting water saturation using rock physics analysis and eostatistics theory: A case study of the Psh8 in GFZ area, Ordos Basin[J]. APPLIED GEOPHYSICS, 2025, 22(2): 331-341.
2025, Vol. 22 
