Abstract:

This paper studies the features of Jiamuhe Formation containing petrology, log and seismic response, in eastern slope belt of Zhongguai Uplift, northwestern Junggar Basin. Therefore we ①summarize volcanic lithological and lithofacies identification template and their distribution pattern, by integrating core section observation, core description, several series of logging data and 3D seismic data; ②distinguish lave, pyroclastic rocks, and volcanic sedimentary rocks from each other by different curve cross plots; ③use texture and structure features template of FMI to identify volcanic subtypes with similar component; ④altogether, identify 3 types 8 kinds of volcanic rocks, and 4 lithofacies considering seismic facies features. Volcanic breccia in explosion facies is widely distributed in the north of the study area, and a series of complicated superimpose volcanic architectures are distributed near wells JIN215, JIN218 and in their northern area. Lave breccia and neutral lava in overflow facies are mainly distributed in the south, while volcanic sedimentary facies is locally distributed. Furthermore, the volcanic reservoir is controlled by lithological facies, structural fracture and weathering process. Ultimately, we find out volcanic breccia in fracture-developed zone near weathering crust is the favorable volcanic rock reservoir type of this area by production test data and fracture prediction.

Key words: Zhongguai Uplift, Jiamuhe Formation, volcanics, lithofacies, controlling factor