在深层—超深层油气保存条件评价研究中,既要关注天然气的物理散失,也要关注高温高压下的烃类化学损耗.热化学硫酸盐还原(TSR)常见于含膏碳酸盐岩层系中,TSR强度越大,烃类损耗程度越大.烃类含量与干燥系数、非烃类含量与酸性气体指数和碳/硫同位素系列指标在一定程度上可以反映TSR强度,但难以满足定量评价的需要.基于四川盆地高含硫化氢或者存在强烈TSR的气藏全部为常压气藏,而邻近的硫化氢含量低且未遭受过TSR的气藏普遍为超压气藏这一基本地质事实,认为TSR烃类化学损耗在超压气藏转变为常压气藏的过程中起着关键作用.因此,利用地层条件下天然气状态参数,尝试建立了TSR烃类化学损耗定量评价方法:ZnPVT状态参数评价法.以普光、元坝、建南和威远等气田的代表性钻井为例,开展了TSR烃类损耗程度评价.结果 表明:普光气田长兴组—飞仙关组气藏、元坝气田长兴组气藏、建南气田长兴组—飞仙关组气藏和威远气田灯影组气藏TSR烃类损耗分别为原始储量的18，、20，、10，和64，.该项评价结果与实际地质条件相符.

In the evaluation of deep-ultra deep oil and gas preservation conditions, not only the physical loss of natural gas should be paid attention, but also the chemical loss of hydrocarbons under high temperature and high pressure should be. Thermochemical sulfate reduction (TSR) is common in gypsum-bearing carbonate systems. The stronger the TSR is, the more the loss of hydrocarbons. Hydrocarbon content and drying coefficient, non-hydrocarbon content, acid gas index and carbon / sulfur isotope series indexes can reflect TSR strength to some extent, but it is difficult to meet the needs of quantitative evaluation. Based on the basic geological fact that all gas reservoirs with high H2S content or strong TSR in Sichuan Basin are normal pressure gas reservoirs, while the adjacent gas reservoirs with low H2S content and not subjected to TSR are generally overpressure gas reservoirs, it is considered that the chemical loss of TSR hydrocarbon plays a key role in the process of overpressure gas reservoir to normal pressure gas reservoir. Therefore, using the state parameters of natural gas under formation conditions, this paper attempts to establish a quantitative evaluation method of TSR hydrocarbon chemical loss: ZnPVT state parameter evaluation method. Taking representative wells in Puguang, Yuanba, Jiannan, and Weiyuan gas fields as examples, the degree of TSR hydrocarbon loss is evaluated. The results show that the TSR hydrocarbon losses of Changxing Formation-Feixianguan Formation gas reservoir in Puguang gas field, Changxing Formation gas reservoir in Yuanba gas field, Changxing Formation-Feixianguan formation gas reservoir in Jiannan gas field, and Dengying Formation gas reservoir in Weiyuan gas field are 18，, 20，, 10，, and 64， of the original reserves respectively. The evaluation result is consistent with the actual geological conditions.