成都理工大学学报（自然科学版）2025，Vol.52Issue(4)：689-703,15.DOI:10.12474/cdlgzrkx.2024060301
浅湖相烃源岩生气潜力评价——以川东北地区须家河组为例
The evaluation and gas potential of shallow lacustrine source rocks:a case study of the Upper Triassic Xujiahe Formation in the northeastern Sichuan Basin,China
摘要
Abstract
Shallow lacustrine source rocks(SLSRs)are generally considered to be poor source rocks.However,some recent exploration discoveries suggest that SLSRs have good gas generation potential.To evaluate the gas potential of SLSRs in the Xujiahe Formation in the northeastern part of Sichuan Basin,in our study we analyse the total organic matter content(TOC),conduct rock-eval pyrolysis,perform maceral observation and analysis,make vitrinite reflectance measurements,and perform a burial history analysis of collected samples.The thicknesses of source rocks are determined based on well logging data,and the amount of generated gas is subsequently calculated.The geological and geochemical characteristics of SLSRs are compared with semi-deep lacustrine source rocks(SDLSRs)from the Xujiahe Formation in the western part of Sichuan Basin.The results show that the thicknesses of the SLSRs range from 15 to 110 m,while those of the SDLSRs vary from 400 to 1 000 m.The TOC of the SLSRs is between 0.56%and 19.80%with an average of 3.68%,whereas the SDLSRs have a content of 0.59%to 47.26%with an average of 4.79%.Both the SLSRs and SDLSRs primarily contain type Ⅲ organic matter.In terms of maturity,both sets of source rocks are mainly in the mature-highly mature stage,but the vitrinite reflectance values of the SLSRs are slightly lower than those of the SDLSRs.The gas generation intensities of the SLSRs are in the range(1.5～8)×108 m3/km2,and those of the SDLSRs are in the range(100～260)×108 m3/km2.Although the form range is much lower than that of the SDLSRs,it can still represents 8.4×1012 m3 of gas.This study indicates that the SLSRs have noticeable gas potential,which is why many gas fields had been discovered in the Mesozoic strata in the northeastern part of Sichuan Basin.关键词
川东北地区/须家河组/浅湖相/烃源岩评价/生气潜力Key words
northeast Sichuan Basin/Xujiahe Formation/shallow lacustrine/source rock evaluation/gas potential分类
天文与地球科学引用本文复制引用
WU Wenjie,HAN Hui,BAI Wenhua,REN Shimeng,CHEN Jintao,XIAO Suqi,WANG Yixing,HE Chunchen,WANG Jiang..浅湖相烃源岩生气潜力评价——以川东北地区须家河组为例[J].成都理工大学学报（自然科学版）,2025,52(4):689-703,15.基金项目
国家自然科学基金项目(41702077) （41702077）
中央高校基本科研业务费专项资金(2682016CX090). （2682016CX090）
