Application of Pre-Stack Geostatistical Inversion in Horizontal well Tracking of Thin Reservoir in well Area

Thin oil layers have become the focus of oil and gas resources exploration due to the large number of oil layers and rich reserves. Fuyu Formation in the sag area of an oil field in the east belongs to a low porosity and low permeability reservoir, and the production of vertical wells is relatively low. The application of horizontal well technology can effectively improve the production. The third member of Fuyuquan Formation has the characteristics of thin interbed reservoir, which increases the difficulty of horizontal well implementation. The resolution of seismic data is limited, and the difference of geophysical response between reservoir and non-reservoir is small, which makes it difficult to solve the problem of thin interbed prediction by wave impedance inversion and pre-stack simultaneous inversion. The application of prestack geostatistical inversion technology can improve the vertical resolution of reservoir prediction, and then accurately depict the spatial distribution of the reservoir. In this paper, taking well F area as the test area, combining with regional geological knowledge, the seismic inversion results with high vertical resolution are obtained through reservoir sensitive parameter analysis and prestack geostatistics inversion technology. It also guides the design of horizontal well trajectory and monitors the change of horizontal well trajectory in real time during implementation. The results show that using pre-stack geostatistics inversion technology can greatly improve the drilling rate of thin oil layers in horizontal wells.

Automated summary

Thin oil layers have become a focus in the exploration of oil and gas resources. The use of horizontal well technology is necessary to improve production in low porosity and low permeability reservoirs. However, the implementation of horizontal wells in thin interbed reservoirs is challenging, and conventional seismic data has limitations in predicting these reservoirs. This study demonstrates the effectiveness of prestack geostatistical inversion technology in improving reservoir prediction and guiding the design and monitoring of horizontal well trajectories.