Multi-stage salt rhythms division and its geological significance of the Xingouzui Formation in Xingou Oilfield,Jianghan Basin
Liu Jiangyan1, Zhang Changmin1, Zhu Rui1, Yang Bo1, Chen Lixin2
1 Key Laboratory of Exploration Technologies of Oil and Gas Resources of Ministry of Education, School of Geosciences,Yangtze University,Wuhan 430100,Hubei
2 Oil Production Plant in Jianghan Oilfield,SINOPEC,Qianjiang 433124,Hubei
Jianghan Basin is a typical saline lacustrine basin during the Mesozoic-Cenozoic in the eastern China. Recently,a tight oil reservoir has been found in the Xingouzui Formation of Xingou Oilfield in Jianghan Basin,and the lithology of the reservoir is dolostone and siltstone associated with salt rhythms. Based on core observation,the data of logging and all kinds of test,we have researched the characteristics of the salt rhythms and its geological significance. The scale of the salt rhythms can be divided into different levels according to the types of salts,the structure and thickness of profile. The profile characteristics of each level and their formation mechanism are analyzed. And the geological significance of salt rhythms from the perspective of palaeoclimate and oil and gas is investigated. Salt rhythms are a direct response to the lake-level variation. The wide development of eury-thermal saline minerals such as calcite and dolomite,indicates that the palaeoclimate was arid to semi-arid in Jianghan Basin during the deposition of Xingouzui Formation in Paleogene. A complete salt rhythm can form a source-reservoir-seal assemblage,which has an important meaning for hydrocarbon generation, accumulation and preservation.
Liu Jiangyan,Zhang Changmin,Zhu Rui et al. Multi-stage salt rhythms division and its geological significance of the Xingouzui Formation in Xingou Oilfield,Jianghan Basin[J]. JOPC, 2015, 17(4): 565-572.
