深层碳酸盐储层再平衡流体包裹体特征及其原始捕获条件确定  

The Characteristics of Re-Equilibrated Fluid Inclusions in Deep Carbonate Reservoirs and Determination of Their Original Trapping Conditions

作　　者：陈勇 韩雨航 鲁雪松[2] 宋一帆 马行陟[2] 范俊佳[2] Chen Yong;Han Yuhang;Lu Xuesong;Song Yifan;Ma Xingzhi;Fan Junjia(School of Geosciences,China University of Petroleum,Qingdao 266580,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580 [2]中国石油勘探开发研究院,北京100083

出　　处：《地球科学》2023年第2期413-428,共16页Earth Science

基　　金：国家自然科学基金项目(No.42173042,41873070)。

摘　　要：深层碳酸盐储层中流体包裹体往往因经历复杂地质演化而发生再平衡,正确判识流体包裹体再平衡对于准确解释古流体演化具有重要意义.以四川盆地安岳气田震旦系灯影组白云岩储层为例,通过岩相学、拉曼光谱测试及显微测温方法结合构造演化史判别了再平衡流体包裹体及其类型,并利用再平衡流体包裹体极值均一温度等数据进行PVT模拟确定了各期包裹体的原始捕获条件.结果表明安岳气田震旦系灯影组储层中第Ⅱ、Ⅲ、Ⅳ期白云石中流体包裹体发生了爆裂变形,第Ⅴ期方解石中流体包裹体发生了拉伸变形,而第Ⅳ期石英中包裹体再平衡特征不显著,其中第Ⅱ、Ⅲ期白云石中流体包裹体在埋藏升温过程中再平衡,而第IV期白云石和第V期方解石中流体包裹体在抬升降温过程中再平衡.第Ⅱ、Ⅲ、Ⅳ期成岩矿物中流体包裹体的捕获压力和捕获温度依次递增,至第Ⅳ期矿物形成时达到峰值,而后第Ⅴ期方解石中流体包裹体的捕获压力和捕获温度较第Ⅳ期则出现降低.结合流体包裹体捕获温压条件和埋藏史准确限定了各成岩期矿物的形成期次和时间,其结果可与同位素定年对比.Complex geological evolution often leads to re-equilibration of fluid inclusions in deep carbonate reservoirs, and correctly identifying re-equilibration is of great significance to accurately explain paleo-fluid evolution. In this paper, taking the dolostone reservoir of Sinian Dengying Formation in Anyue gas field in Sichuan Basin, China as an example, the characteristics and types of re-equilibration are identified by petrography, Raman spectroscopy and micro-thermometry combined with the history of tectonic evolution, and original trapping conditions of each stage fluid inclusions are determined by PVT simulation based on the maxima or minima homogenization temperature of re-equilibrated fluid inclusions. The results show that fluid inclusions indolomi tes at stage Ⅱ, Ⅲ and Ⅳ are deformed by decrepitation, and fluid inclusions in calcite at stage V are stretched, while re-equilibration characteristics of fluid inclusions in quartz at stage Ⅳ are not obvious. Re-equilibration of fluid inclusions in dolomites at stage Ⅱ and Ⅲ are in the process of burying and temperature increasing, while re-equilibration of fluid inclusions in dolomites at stage Ⅳ and in calcite at stage V are in the process of uplift and temperature reducing. The trapping pressure and trapping temperature of fluid inclusions increase from stage Ⅱ to stage Ⅳ, reaching the peak of temperature and pressure at stage Ⅳ, while the trapping pressure and trapping temperature of fluid inclusions in calcite at stage V are lower than those at stage Ⅳ. Combining trapping conditions and burial history can accurately determine the formation age of minerals at different diagenetic sequence, and the results can be compared with data from isotopic dating.

关 键 词：再平衡流体包裹体 古压力 深层碳酸盐储层 白云岩 四川盆地 石油地质 

分 类 号：P59[天文地球—地球化学]