对深层—超深层油气保存条件的评价,既要考虑物理散失也应考虑化学损耗,如烃类氧化蚀变为非烃类气体.热化学硫酸盐还原作用(TSR)常见于含膏碳酸盐岩层系中,古油藏、膏岩、地层水、高温和孔隙型碳酸盐岩储层是控制TSR发生的5个主要因素.烃类含量与干燥系数、非烃类含量与酸性气体指数以及碳、硫同位素等3类强度指标在一定程度上可以反映TSR强度及定性评价烃类化学损耗程度,但都难以满足定量评价的需要.因此,需要建立新的TSR烃类损耗评价方法,从而完善深层—超深层海相碳酸盐岩层系油气保存条件评价技术.

The evaluation of deep-ultra deep oil and gas preservation conditions should concern not only physical loss but also chemical loss, such as the oxidation of hydrocarbons into non-hydrocarbon gases. Thermochemical sulfate reduction (TSR) commonly occurs in gypsum-bearing carbonate strata. There are five main factors controlling TSR, which are paleo-oil reservoir, gypsolyte, formation water, high temperature and porous carbonate reservoir respectively. Hydrocarbon content and dry gas coefficient, non-hydrocarbon content and acidic gas index, carbon and sulfur isotopic compositions are three kinds of TSR intensity index. To a certain extent, they can qualitatively reflect the intensity of TSR and be used for qualitatively evaluating the chemical loss of hydrocarbons, but they can't meet the needs of the quantitative evaluation. Therefore, it is necessary to establish a new method of TSR hydrocarbon loss evaluation for the deep-ultra deep marine sequences.