Research and Application of Shale Oil Fracture Prediction Method Based on Azimuthal Anisotropy Analysis
摘要
The continental rifted lake basins of the Jiyang Depression with well-developed fractures have abundant shale oil and gas resources. The fractures can effectively improve the productivities of shale oil reservoirs, but they also increase the risk of drilling, causing well leakages. Therefore, accurately predicting the fractures is the main problem that urgently needs to be solved in the shale oil exploration and development in this block. In this paper, the dynamic time warping (DTW) is used for correction of the residual anisotropic moveout in OVT gathers. Based on the moveout caused by the propagation of seismic waves in HTI media, the direction and relative strength of azimuth anisotropy can be determined, and ultimately predicting the direction and density of crack development. Applying this method to the prestack data in Niuzhuang sub-sag for fracture prediction, and comparing it with the fractures predicted by the commercial software, the results obtained by the two methods are similar. Comparing with the imaging logging results and the leakage locations during the drilling, the fractures predicted by the proposed method are more reliable, which can provide strong technical support for the efficient development of shale oil.