摘要
S88及TS1井是塔河油田钻遇下古生界巨厚白云岩地层的典型钻井。对这2口井的岩样进行岩心观察、矿物鉴定、流体包裹体测温及地球化学研究表明,S88井奥陶系蓬莱坝组及TS1井寒武系下丘里塔格组白云岩地层除受原地盆地流体的影响外还可能存在深部热液流体的影响,流体性质以高温、富87Sr且携带热化学硫酸盐还原作用产物(H2S和CO2)的酸性流体为主。热液流体的运移导致这2口井深部储层次生溶蚀孔洞的发育,使得储集物性得到改善。研究还表明,这2口井疏导层的存在为深部热液流体的向上运移及进入储层提供关键通道。S88井热液流体对储层的影响主要受控于岩相和裂缝的发育程度,白云岩段储层好于灰岩段,裂缝发育段储层优于不发育段;TS1井白云岩储层的发育主要受控于岩性组合,下部井段的膏盐层与白云岩层的共生可能是其岩石物性优于上部纯白云岩井段的主要原因。
87Sr/86Sr,δ34S and fluid inclusions were analyzed on the fracture fillings of thick dolomites in Wells S88 and TS1 in the Tahe Oilfield.The results indicate that the deep hydrothermal fluid has a significant effect on the dolomite reservoirs of the Penglaiba Formation from Well S88 and the Qiulitage Formation from Well TS1.The hydrothermal fluid is characte-rized by high temperatures and 87Sr enrichment,and may have up-migrated with H2S and CO2,which resulted likely from thermochemical sulfate reduction（TSR） of hydrocarbons.The migration of acidic hydrothermal fluid resulted in dissolution of carbonates and generation of abundant secondary vugs and micropores in Wells S88 and TS1,thereby,which improves the quality of reservoir properties.Also,faults and micro-fractures may have served as migration pathways for the hydrothermal fluid in Wells S88 and TS1.The degree to which the hydrothermal fluid influenced on quality of Penglaiba Formation in Well S88 was mostly controlled by lithology and cracks.The reservoir of dolomite strata is better than limestone strata,and fracture zone is prone to form better reservoir.In Lower Qiulitage Formation of Well TS1,TSR was enhanced by the occurrence of gypsum/anhydrite in dolomite strata,and thus might be one of main controlling factors in the development of deep favorable reservoirs.
出处
《石油实验地质》
CAS
CSCD
北大核心
2010年第1期46-51,共6页
Petroleum Geology & Experiment
基金
国家重大基础研究发展计划(973计划)(2006CB202304)项目
国家自然科学基金委-中石化联合项目(40839906)资助
