Evaluation of the Upper Paleozoic source rocks in Western Henan, China: A case study in Luoyang Basin

The Upper Paleozoic coal-measure strata in the Western Henan has good unconventional oil and gas exploration prospects. However, there is a lack of systematic evaluation of potential source rocks. Aiming at the fully exposed the coring boreholes in the Upper Paleozoic in the Western Henan (Luoyang Basin), this paper systematically collects and analyzes samples. Considering the sedimentary environmental conditions, this paper evaluates the Upper Paleozoic source rocks in the Western Henan. The results show that the source rocks include mudstone, carbonate rocks, and coal rocks; Vertically, the source rocks are continuously distributed in the lower layer below the Dazhan sandstone of Shanxi Formation, and only locally developed above Dazhan sandstone; The organic matter type of coal and mudstone is type III, and the kerogen type of carbonate rocks is also type III, which is different from the organic matter type of general carbonate rocks (type I), which is related to the sedimentary environment. The average value of vitrinite reflectance is more than 4.27% and the average value of maximum pyrolysis temperature is more than 430 degrees C. The thermal evolution degree of source rocks reached the mature to over-mature stage, which tends to gradually increase with the increase of depth, which may be related to Meso-Cenozoic tectonothermal events. (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

The study systematically evaluates the source rocks in the Upper Paleozoic in Western Henan, finding mudstone, carbonate rocks, and coal rocks with type III organic matter and mature to over-mature thermal evolution stage. The thermal evolution tends to increase with depth, possibly related to Meso-Cenozoic tectonothermal events.