Abstract:

Dongying Formation in the southern Liaodong Bay Basin contains a series of complex reservoirs controlled by both structure and lithology. At present, industrial oil and gas flow have been obtained after drilling. The reservoir is thin and the lithology changes greatly laterally with complex distribution and strong heterogeneity, causing great difficulties to oil and gas exploration. High-precision seismic inversion method is an effective way to solve the complexity of such oil and gas reservoirs. In this paper, the seismic phase controlled nonlinear random inversion method is used to predict the thin sandstone reservoir after stacking seismic inversion in the target interval of Dongying Formation. By reconstructing and decompressing the logging curve, the acoustic logging curve can meet the requirements of high-precision inversion. Firstly, a low-frequency velocity model is established with the constraint of seismic phase interface, and then the resolution of inversion results is improved based on the nonlinear random algorithm. Combined with the random simulation theory, the inversion results agree with to the seismic data volume. Good results have been obtained in practical application in this area, which can effectively improve the resolution of seismic data. The inversion results can characterize changes in seismic waveform and highlight the geological and sedimentary characteristics. The inversion results are in good agreement with the actual drilling data and can effectively identify thin sandstone reservoirs. Based on the inversion results, this paper characterizes the reservoir distribution of Dongying Formation in Liaodongwan depression, which provides a reliable basis for further exploration and development.

Key words: facies controlled stochastic inversion, well-logging curve reconstruction, decompressing correction, reservoir
characterization, Dongying Formation, Liaodong Bay Basin