Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region,Tarim Basin,NW China  

作　　者：Rong-Hui Fang Mei-Jun Li Hai-Tao Lü T.-G.Wang Yuan Yuan Yong-Li Liu Zhi-Yong Ni 

机构地区：[1]State Key Laboratory of Petroleum Resources and Prospecting,College of Geosciences,China University of Petroleum,Beijing 102249,China [2]Exploration and Development Research Institute,Northwest Oilfield Branch Corporation,SINOPEC,Urumqi 830011,Xinjiang,China [3]Research Institute of Shaanxi Yanchang Petroleum(Group)Co.Ltd,Xi'an 710075,Shaanxi,China

出　　处：《Petroleum Science》2017年第4期662-675,共14页石油科学（英文版）

基　　金：funded by the National Natural Science Foundation of China(Grant No.41272158);the Foundation of State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-1503)

摘　　要：Geochemical analysis of 64 oils sampled from an Ordovician carbonate reservoir in the Tuoputai region was undertaken to study the composition of molecular markers. All the oils have similar geochemical characteristics and belong to a single oil family. They are presumed to derive from the same source kitchen and have similar oil charging history. A histogram of homogenization temperatures(Th) of aqueous inclusions in reservoir rocks shows a bimodal distribution pattern, indicating that the Ordovician reservoir has been charged twice. Coupling the measured Th(°C) with the burial and geothermal histories reconstructed using 1D basin modeling, we relate the homogenization temperature to the relevant geological ages: i.e.,425–412 and 9–4 Ma, corresponding to the Middle to Late Silurian and the Miocene to Pliocene, respectively. The oil filling orientation and pathways are traced using molecular indicators related to alkyldibenzothiophenes and benzo[b]naphthothiophenes. The oil charging orientation is from south to north generally. It can be predicted that the Ordovician reservoirs were sourced from a kitchen located to the south of the Tuoputai region, most probably between the Awati and Manjiaer Depressions. Traps located in the southern side of the Tuoputai region, along the oil charging pathways, should therefore be preferred oil exploration targets.Geochemical analysis of 64 oils sampled from an Ordovician carbonate reservoir in the Tuoputai region was undertaken to study the composition of molecular markers. All the oils have similar geochemical characteristics and belong to a single oil family. They are presumed to derive from the same source kitchen and have similar oil charging history. A histogram of homogenization temperatures(Th) of aqueous inclusions in reservoir rocks shows a bimodal distribution pattern, indicating that the Ordovician reservoir has been charged twice. Coupling the measured Th(°C) with the burial and geothermal histories reconstructed using 1D basin modeling, we relate the homogenization temperature to the relevant geological ages: i.e.,425–412 and 9–4 Ma, corresponding to the Middle to Late Silurian and the Miocene to Pliocene, respectively. The oil filling orientation and pathways are traced using molecular indicators related to alkyldibenzothiophenes and benzo[b]naphthothiophenes. The oil charging orientation is from south to north generally. It can be predicted that the Ordovician reservoirs were sourced from a kitchen located to the south of the Tuoputai region, most probably between the Awati and Manjiaer Depressions. Traps located in the southern side of the Tuoputai region, along the oil charging pathways, should therefore be preferred oil exploration targets.

关 键 词：Oil population Oil charging events Fluid inclusion 1D numerical modeling Oil filling pathway 

分 类 号：TE344[石油与天然气工程—油气田开发工程]