川西坳陷中段上三叠统须四段经历了复杂的成岩作用以及强烈的构造演化,导致了天然气藏成藏的多期性,决定了天然气聚集和分布的复杂性。因此,对川西坳陷中段须四段天然气藏成藏期次的研究一直是勘探领域研究的重点,至今尚未取得统一的认识。通过采集新场、成都凹陷、中江—回龙、龙门山前、知新场不同构造单元重点井砂岩样品进行包裹体测试分析,并对须四段上、下2个亚段进行成藏期次的系统研究。对包裹体基本特征镜下观察及均一温度埋藏史—热史图投点的研究表明:川西坳陷中段须四下亚段为一期成藏,主要在早—中燕山期便进行了大规模的天然气充注,且后期得到了较好的保存;须四上亚段具有2期成藏的特征,早期成藏发生在早—中燕山期,但大都经过后期的改造,此后在早喜马拉雅期再次进行天然气充注,即第二期成藏。通过对晚侏罗世、早白垩世川西须四段古构造分析,进一步明确了燕山期、喜马拉雅期古构造对川西坳陷各构造单元须四段天然气聚集和分布的控制作用。 The upper section of the Upper Triassic Xu 4 in the central western Sichuan Depression underwent complicated diagenesis and strong tectonic evolution, leading to the multi-period of gas accumulation and determining the complexity of natural gas accumulation and distribution. Therefore, the study of the accumulation period of the Xu 4 member gas reservoirs in the middle section of the western Sichuan depression has been the focus of the exploration field, and so far no unified understanding has been obtained. The inclusion samples of sandstone samples collected from Xinchang, Chengdu sag, Zhongjiang-Huilong, Longmen Piedmont and Zhixin site with different tectonic units were tested for inclusion analysis, and the upper and lower sub-sections of the fourth member were collected for reservoir formation Systematic research. Microscopic observation of the basic characteristics of inclusions and homogenization temperature burial history-thermal history mapping study shows that: the middle section of the western Sichuan-Sichuan sub-fourth sub-interval is a period of accumulation, mainly in the early-middle Yanshan period, a large-scale Of the natural gas charge, and the later period has been well preserved. The fourth member of the Upper Member has the characteristics of second-stage accumulation. Early accumulation took place in the early-middle Yanshanian period, but most of them were rebuilt in the later period. Later, during the early Himalayan period, Gas filling again, the second phase of accumulation. Based on the palaeo-tectonic analysis of the fourth member of Xujiahe Formation in the western Sichuan during the Late Jurassic and Early Cretaceous, the Yanshanian and Himalayan palaeostructures further clarified the control over the accumulation and distribution of natural gas in the fourth member of each structural unit in the western Sichuan Depression.