烃源岩滞留油气作用及其对泥页岩含油气率的影响

摘要

The residual shale hydrocarbon is universal,and the residual oil and gas exist in a variety of phases,which include separate phase,absorbed phase,water-dissolving phase and oil-dissolving phase.Among them,the oil is mainly in separate and absorbed phases,while gas residues in many ways.Based on the principle of material balance,a new method of calculating the residual hydrocarbon content according to variance of calculate the residual hydrocarbon index was put forward.The results show that the quantity of residual shale oil and gas is mainly affected by the abundance,type and evolution degree of the organic matter,and other factors such as mineral composition,temperature and pressure conditions.Generally,the greater the abundance of the organic matter and the higher the temperature and pressure,the greater the amount of residual oil and gas.The properties of residual Shale oil and gas are mainly affected by the type and the evolution degree of the organic matter.Source rocks of high evolution degree and type-Ⅲ organic matter give priority to residual gas and the residual oil mainly exists in source rocks of type-Ⅰ organic matter and low evolution degree.The amount of the residual oil in upper member mudstone in fourth Shahejie Formation of Dongying Sag was worked out as 58.42 × 10s t,which shows that there are good prospects of shale oil in the exploration area.%泥页岩滞留油气的形式主要包括游离态、吸附态、水溶态和油溶态,其中,石油主要以游离态和吸附态滞留为主,天然气则以多种方式滞留.依据物质平衡原理,提出了依据滞留烃指数变化计算泥页岩滞留油量的方法.研究结果表明:泥页岩滞留油气量主要受有机质的丰度、类型和演化程度以及矿物组成和温压条件等影响.一般地,有机质丰度越大、温度压力越高滞留油气量越大.泥页岩滞留油气的性质主要受有机质类型和演化程度影响,Ⅲ型有机质和高演化程度的泥页岩以滞留气为主,而Ⅰ型有机质和低演化程度的泥页岩以滞留油为主.东营凹陷沙四上亚段泥岩滞留油量为58.42×108t,表明泥岩具有较好的含油前景.