1. College of Geo-exploration Science and Technology, Jilin University, Changchun 130026, China;
2. State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100083, China;
3. Key Laboratory of Shale Oil/Gas Exploration and Production Technology, SinoPEC, Beijing 100083, China;
4. Exploration & Production Research Institute, SinoPEC, Beijing 100083, China

Based on the rock physics model of shale, according to the rock physics model of equivalent self consistent approximation (SCA), the authors build the quantitative relationship between P-wave, S-wave and the rock density, rock composition and rock porosity to find a pore aspect ratio can minimize the error of the theoretical P-wave velocity and the actual P-wave velocity. Then the authors use this pore aspect ratio as the constraint condition to achieve the prediction of shear wave velocity. The inversion algorithm uses the artificial fish swarm algorithm to calculate the optimal aspect ratio, and compares the predicted shear wave velocity with the actual measured shear wave velocity which proves the effectiveness of the artificial fish-swarm algorithm.