利用流体包裹体分析和计算油气的充注史和古流体势——以鄂尔多斯盆地榆林地区上古生界为例

Analysis and calculation of hydrocarbon accumulation history and paleocurrent potential by studying fluid inclusions——An example from the Upper Paleozoic in Yulin,Ordos basin

通过包裹体测温、荧光光谱分析及流体势分析,结合区域地质资料,认为鄂尔多斯盆地榆林地区上古生界油气具有多期连续性充注特征。从晚三叠世中期到早白垩世末期,油气不断注入,烃类组分随埋深由低成熟到高成熟,虽可划分为6期,但应为连续充注的一期成藏,其中早侏罗世中期—中侏罗世末期和中侏罗世末期—早白垩世末期是两个大规模天然气充注时期。用VTFLINCPVT模拟软件计算包裹体流体势结果显示,榆32井是长期的低势区,榆43-8井和榆25井等流体势较高。

Research on fluid inclusion temperature, fluorescent spectroscopy, current potential analysis, and regional geological data, indicates that the Upper Paleozoic pools are characterized by multistage but continuous charging in Yulin, Ordos basin. From the middle Late Triassic to the end of the Early Cretaceous, hydrocarbons were continuously inputting into the reservoirs and their maturity evolved from low to high along with increasing burial depth. The charging is actually a continuous one-stage process, though it can be divided into 6 stages, of which the middle Early Jurassic-end of Middle Jurassic and the end of Middle Jurassic-end of Early Jurassic are two large scale gas charging stages. The calculated fluid inclusion potentials with PVT simula- tion software of VIFLINC indicate that paleocurrent potential is low in well Yu32 and high in well Yu43-8 and Yu25.