Abstract: A set of unconventional marl reservoirs are developed in the Member 1 of Maokou Formation in Hechuan-Tongnan area of Sichuan Basin, with great resource potential but lack of deep research. Aiming at the identification problem of favorable marl reservoirs and combining with geological, core and logging data, the paper studies the lithofacies, accumulation characteristics, gas-bearing properties and influencing factors of the reservoirs, identifies the favorable reservoir characteristics of the Member 1 of Maokou Formation, proposes a quantitative lithofacies identification method based on using the sorting coefficient and low resistivity surface ratio from imaging logging data, and further calculates the total organic carbon (TOC) content by use of multiple regressive method. Moreover, efforts are made to optimize the multi-mineral interpretation model containing talc, improve the calculation accuracy of mineral component content and porosity, and finally establish the identification criteria for favorable reservoirs and perform fine interpretation on single wells in the study area. The research results show that the development of the favorable reservoirs of the Member 1 of Maokou Formation is mainly controlled by factors such as lithofacies, TOC content, physical properties, mineral component and content, and on this basis, the logging evaluation criteria and results for favorable reservoirs are in good agreement with gas test results. Regionally, the multi-well interpretation results show that the Member 1 reservoir of Maokou Formation is comparable in transverse direction, and the thickness of the reservoir gradually thickens from SE to NW. The research understanding and method have important guiding significance for target selection during gas testing and marl reservoir "sweet spot" prediction of the Member 1 of Maokou Formation in Hechuan-Tongnan area of Sichuan Basin, and have broad application prospect.

Key words: unconventional, marl, favorable reservoir, logging evaluation, Hechuan-Tongnan, Member 1 of Maokou Formation

摘要： 四川盆地合川—潼南地区茅口组一段（茅一段）发育一套泥灰岩非常规储层，资源潜力巨大，但研究程度低。针对泥灰岩有利储层识别难的问题，综合地质、岩心和测井资料，对储层的岩相特征、储集特征、储层含气性及影响因素开展了研究，明确了茅一段有利储层的特征，提出了利用成像测井资料提取的分选系数和低阻面比率开展岩相定量识别的方法，并应用多元回归法计算出总有机碳（TOC）含量，优化了含滑石的多矿物解释模型，提高了矿物组分含量和孔隙度的计算精度，最后建立了有利储层的识别标准并对区域内的单井进行了精细解释。研究结果表明，茅一段有利储层的发育主要受岩相类型、TOC含量、物性、矿物组分及含量等因素控制，而以此为基础建立的有利储层测井评价标准及评价结果与试气结果吻合较好；区域上，多井的解释结果显示茅一段储层在横向上可对比，在平面上储层厚度由SE向NW方向逐渐变厚。研究认识及方法对四川盆地合川—潼南地区茅一段泥灰岩储层的试气选层和甜点展布预测等具有重要指导意义，应用前景广阔。

关键词: 非常规, 泥灰岩, 有利储层, 测井评价, 合川—潼南, 茅口组一段