Research on Seismic Prediction Methods for Pore Pressure in the Canglangpu Formation Carbonate of JT1 Well Area in Sichuan Basin
Zhao Hu*, Yu Huan, Zhang Hang, Zhang Jie-wei, Li Wen-hao, Yang Heng, Dai Jing-yun, An Hong-yi
1.Sichuan Province University Key Laboratory of Natural Gas Geology, SWPU, Chengdu 610500;
2. School of Geoscisence and Technology, Southwest Petroleum University, Chengdu 610500;
3. Geophysical Division, PetroChina Southwest Oil & Gasfi eld Company, Chengdu 610041;
4. Southwest Oil&Gas fi eld Company Northeastern Sichuan Oil and Gas District, Dazhou 635000;
5. Petrochina Southwest Oil&Gas fi eld Company Exploration Division, Chengdu 610041.
Abstract：
The Canglangpu Formation in the JT1 well area of the Sichuan Basin exhibits strong lateral heterogeneity and complex overpressure mechanisms, leading to ambiguous pore pressure distribution characteristics. Conventional prediction methods, such as the Equivalent Depth Method, are either inapplicable or yield unsatisfactory results (e.g., Fillippone’s method), contributing to frequent drilling incidents like gas kick, overfl ow, and lost circulation, which hinder the safe and effi cient exploration of natural gas. To address these challenges, this paper integrates lithology, physical properties, and overpressure mechanisms of the Canglangpu Formation. From a petrophysical perspective, a pore pressure prediction model independent of lithology and overpressure mechanisms was developed by combining the poroelasticity theory, linear elastic Hooke’s Law, and Biot’s effective stress theory, with an analysis of the relationship between carbonate rock strain, external stress, and internal pore pressure. Unlike conventional methods, the model does not rely on the establishment of a normal compaction trend line. Pre-stack seismic inversion was applied to achieve 3D pore pressure prediction for the formation. Results indicate high accuracy, with a relative error of less than 5% compared to measured data, and strong consistency with actual drilling events. The proposed method provides robust technical support for pore pressure prediction in carbonate formations and drilling geological design.
. Research on Seismic Prediction Methods for Pore Pressure in the Canglangpu Formation Carbonate of JT1 Well Area in Sichuan Basin[J]. APPLIED GEOPHYSICS, 2025, 22(2): 432-446.
2025, Vol. 22 
