关键词: 青石峁气田, 成藏条件, 地质条件, 勘探开发, 关键技术

Abstract: Qingshimao gas field was explored in 2022, which has the proved area of 2 151 km² and proved reserves of 1 459×10⁸m³, making it the eighth gas field of hundred billion cubic meters in Changqing oilfield. By reviewing the exploration history of Qingshimao gas field, the geological characteristics of natural gas accumulation are summarized as follows. The main gas-bearing stratum of Qingshimao fas field is the Member 8 of the Permian Xiashihezi Formation; the main source rocks are coal seams and dark mudstones in Carboniferous Benxi Formation, Permian Taiyuan Formation and Shanxi Formation, characterized by widespread hydrocarbon generation. Delta front subfacies sedimentary system is developed, where the distributions of sand bodies are controlled by multiple provenances, multiple drainage systems, strong supply and multiple channel. The reservoir is dominated by fluvial channel sandstones with an average porosity of 7.9% and an average permeability of 0.363 mD, indicating a tight reservoir, and the connectivity of sand bodies is controlled by their distribution. The pressure coefficients of gas reservoir range from 0.78 to 0.90, demonstrating a low pressure gas reservoir. The reconstructed gas reservoir under the control of lithology and structure was formed due to long-term continuous charging under low hydrocarbon generation intensity, adjustment and transformation of tight reservoirs by fault systems, and high source-reservoir pressure difference. The three-dimensional seismic exploration, sand body fine characterization, and well location selection under complex gas-water relationships are key technologies for exploration and development of Qingshimao gas field.

Key words: Qingshimao gas field, accumulation condition, geological condition, exploration and development, key technology