The Application Of AVO Technology And Multi-attribute Analysis In Coal-bed Methane Exploration

In this paper, using AVO technology and multi-attribute analysis comprehensively, a coal-bed methane prediction flow is established, which includes coal-bed thickness prediction, fracture prediction and gas accumulating area prediction.Firstly, the feasibility of AVO technology in coal-bed methane data is discussed, including the distinguishability of AVO technology for the gas content of coal bed, and the influence of coal-bed thickness and surrounding-rock lithology in AVO effect. Then rock-physics analysis is applied to make cross-plots of elastic parameters, for choosing the gas-sensitive parameters. Finally, do coal-bed methane prediction to real data from the perspective of thickness prediction, fracture prediction and gas accumulating area prediction. In coal-bed thickness prediction, through the optimization of post-stack inversion methods, geostatistical inversion is chosen to predict the thickness of coal bed which the resolution is much higher. In fracture prediction, the application results of coherence technology and ant-tracking technology are compared. And then they are used to predict fractures of different scales accordingly. In the prediction of gas accumulating area, multiple attributes are achieved by the comprehensive application of amplitude attributes, frequency attributes, absorption and attenuation technology, AVO attributes and pre-stack AVA simultaneous inversion. In the process of attribute optimization, the multi-solution problem in comprehensive interpretation is eliminated. The interpretation flow in real data gets relatively good application effect.