摘要
塔河油田奥陶系缝洞型储层是该区最重要的油气生产层段,古岩溶作用产生的大量溶洞作为油气的存储空间,具有举足轻重的意义。通过对11口井充填溶洞的岩心观察,划分出化学沉(淀)积岩相、搬运型岩相、垮塌型岩相、渗流充填相4大类溶洞充填相。搬运型岩相为溶洞的早期充填产物,当地表岩溶的溶蚀作用发展到一定程度时岩石会发生崩落,崩落的结果就产生了垮塌型岩相,后期的渗流充填相以填隙物的形式充填在垮塌型岩相里。据区内Ta井的典型溶洞充填特征,归纳出其充填序列为上部的溶洞破裂相、中部的塌陷相及下部的海水侵入充填相。溶洞充填物中微量元素、稀土元素等的地球化学特征,证实区内存在海水-淡水混合岩溶,对油田的开发生产具有很好的指导意义。
The Ordovician carbonate fracture-cavern reservoir has been the most important oil and gas production interval in Tahe oilfield.Large numbers of karst caverns conduced by the paleo-karstification play an important role in the oil and gas storage.The karst caverns filled with sedimentary deposits are divided into four karst cavern filled facies,which are speleothem facies,transposition lithofacies,collapse-breccia facies,vadose filling facies,in 11 karst caverns filled wells.The transposition lithofacies is the karst cavern fillings at the early stage.When the corrosion of surface karst develops to a certain extent,the rocks break down to form the collapse-breccia facies,and later stages the vadose fillings is the interstitial matrix in collapse-breccia facies.From the model of well Ta,the authors get a caverns＇ filling order,which has the top cavern disturbed facies,middle collapse facies and the bottom marine influx filled facies.The trace element and rare earth element geochemistry characterization of cavern fillings proves the marine-meteoric water mixed karst,which will guide the production of the oilfield.
出处
《现代地质》
CAS
CSCD
北大核心
2010年第2期287-293,共7页
Geoscience
基金
中国石化西北油田分公司勘探研究院项目(KY-S2006-031)
关键词
塔河油田
奥陶系
溶洞充填物
地球化学
Tahe oilfield
Ordovician
karst cavern filling
geochemistry
