基于包裹体PVTx数值模拟恢复油藏古温压---存在的问题、对策及应用实例  

Reconstruction of paleo-temperature and pressure of oil reservoirs based on PVTx simulation:problems,strategies and case studies

作　　者：席斌斌[1,2,3] 蒋宏 许锦[1,2,3] 陈强路 尤东华[1,2,3] XI Binbin;JIANG Hong;XU Jin;CHEN Qianglu;YOU Donghua(SINOPEC Key Laboratory of Petroleum Accumulation Mechanisms,Wuxi,Jiangsu 214126,China;State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Wuxi,Jiangsu 214126,China;Wuxi Research Institute of Petroleum Geology,SINOPEC,Wuxi,Jiangsu 214126,China)

机构地区：[1]中国石化油气成藏重点实验室,江苏无锡214126 [2]页岩油气富集机理与有效开发国家重点实验室,江苏无锡214126 [3]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214126

出　　处：《石油实验地质》2021年第5期886-895,共10页Petroleum Geology & Experiment

基　　金：国家自然科学基金委员会企业创新发展联合基金集成项目“海相深层油气富集机理与关键工程技术基础研究”(U19B6003);中国石化基础前瞻课题“深部碳酸盐岩储层地质作用机理及定量表征关键技术研究”(JC-2020-KT002-3)。

摘　　要：包裹体PVTx数值模拟是恢复油藏古温压的重要手段。由于无法精确地确定油包裹体的组成,以及油包裹体成分在地质演化过程中可能发生不可逆的次生变化,现有方法恢复的古温压存在不确定性。一般而言,与油包裹体伴生的盐水包裹体成分相对简单,且遭受次生蚀变影响的概率较低。因此,尝试将伴生的盐水包裹体作为独立的地质压力计在塔里木盆地顺南地区SN1井进行了应用研究。包裹体岩相学研究显示,SN1井高角度裂缝充填的方解石中,发育大量遭受过次生蚀变的含沥青烃包裹体及伴生的盐水包裹体。包裹体古温压恢复显示,伴生的盐水包裹体呈现异常高的均一温度(超过170℃),均一压力波动范围大,且存在异常高压(39.1 MPa起,甚至超过165.8 MPa)。上述现象可能与热流体活动和原油充注后所经历的裂解增压过程有关。基于盐水包裹体均一压力的最低值,结合该地区埋藏史和热演化史分析,推测热液活动时间为海西期。上述认识与该地区NE向走滑断裂活动具有较好的时空匹配关系。综上所述,油包裹体伴生的盐水包裹体作为独立的地质压力计,可以用来恢复油藏古温压的演化轨迹,并限定古流体活动的时间,能够在一定程度上弥补现有方法的不足。The PVTx simulation of fluid inclusions is a valuable method for the reconstruction of paleo-temperature and pressure of oil reservoir.Since the accurate composition of oil-bearing inclusion is very difficult to be obtained and the composition may be altered during secondary alteration processes,it may cause uncorrected results.Compared to oil-bearing inclusion,the composition of accompanied aqueous inclusion is relatively simple and could hardly be affected during secondary alteration processions.As a result,accompanied aqueous inclusions were applied to reconstruct the paleo-temperature and pressure of well SN 1 in the South Shuntuoguole area of Tarim Basin.Gas-oil-bitumen bearing inclusions and aqueous inclusions are co-existed in calcite veins of well SN 1.The homogenization temperatures of aqueous inclusions were higher than 170℃,and the homogenization pressure of aqueous inclusions is significantly fluctuating from 39.1 MPa to over 165.8 MPa.The unusually high homogenization temperature of aqueous inclusions may be caused by hydrothermal fluid activity while the fluctuation of homogenization pressure of aqueous inclusions may be caused by oil cracking.The lowest homogenization pressure of aqueous inclusion was applied to determine the charge time of hydrothermal fluid,which is Hercynian.The charging time of hydrothermal fluid is in accordance with the active time of NE-trending strike-slip faults in the South Shuntuoguole area.Thus,the co-existing aqueous inclusions potentially can be applied to reconstruct the paleo-temperature and pressure of oil reservoir to make up the deficiency of present methods.

关 键 词：含甲烷盐水包裹体 古温度 古压力 PVTx模拟 顺南地区 塔里木盆地 

分 类 号：TE135[石油与天然气工程—油气勘探]