Abstract:
The organic reef of Changxing Formation in the LHC area of northeastern Sichuan Basin, as the main production layer, has shifted from the exploration stage to the development stage after several years of development. In addition, an accurate assessment of their development potential is crucial and needs to be achieved through geological modeling. However, deep organic reefs have blurred boundaries and unclear internal structural responses due to insufficient seismic imaging resolution. Moreover, there is a significant difference in porosity between organic reefs and non-reefs under the same impedance background, making traditional modeling methods fail to achieve accurate characterization of reservoir parameters. To solve this problem, a facies controlled modeling method based on seismic data processed by a steerable pyramid method for geological feature enhancement was proposed. First, the steerable pyramid method decomposed seismic data into multiple scales and multiple directions and reconstructed the data for geological feature enhancement, improving the accuracy of organic reef identification. Secondly, according to the seismic response characteristics of the organic reef and the restoration results of palaeogeomorphology, the three-dimensional favorable facies zone model of the organic reef was established. Finally, the inversion results of the reservoir were extracted into the geological model, and Bayesian facies controlled modeling was carried out to improve the consistency of geological rules with in-well and seismic information and realize the fine characterization of reef porosity. The application test shows that the porosity distribution of the facies controlled model is point-like, which is more consistent with the distribution characteristics of the organic reef and has a good agreement with the logging results, which proves that the proposed method is reliable. This method can facilitate the precise calculation and description of reservoir reserves in the future.