基于油气运移最小能耗率原理的成藏期地层倾角窗口研究——以鄂尔多斯盆地上古生界致密气藏为例  

Study on stratigraphic dip window in accumulation period based on the principle of minimum energy dissipation rate of oil and gas migration: Case study of the Upper Paleozoic tight gas reservoirs in the Ordos Basin

作　　者：王任一 许彪 李江涛 张登辉 陈之龙 Renyi WANG;Biao XU;Jiangtao LI;Denghui ZHANG;Zhilong CHEN(School of Petrochemical&Energy Engineering,Zhejiang Ocean University,Zhoushan 316022,China;PetroChina Qinghai Oilfield Company,Dunhuang 736202,China)

机构地区：[1]浙江海洋大学石油化工与环境学院,浙江舟山316022 [2]中国石油青海油田分公司,甘肃敦煌736202

出　　处：《天然气地球科学》2024年第1期30-40,共11页Natural Gas Geoscience

基　　金：浙江省自然科学基金(编号:LY20D020002)资助~~。

摘　　要：对于成藏期地层倾角与油气聚集资源量之间关系的研究,国内外学者多局限在勘探实践案例统计分析及简化物理模拟实验研究方面,缺少对成藏期地层倾角与油气聚集资源量之间理论关系的研究。从油气运移最小能耗率原理出发,在理论上严格证明了油气运聚系统成藏期地层倾角窗口的存在。处于成藏期地层倾角窗口,油气运移有效驱动功率最弱,油气运聚系统能耗率最小,油气运聚效率最高,赋存发育油气资源量最大。回答了成藏期地层倾角到底是较大还是较小时有利于成藏的问题,揭开了侯连华等(2021)对国内已投入商业开发的44个天然气有效区带和49个石油有效区带的油气资源量,与其主成藏期平均地层倾角二者间呈一“开口向下抛物线”统计特征之谜。同时,利用该理论对鄂尔多斯盆地上古生界致密气藏地层倾角窗口演化变迁进行研究。上古生界高压致密古气藏由净浮力梯度、剩余压力梯度和排驱压力梯度三者之和为其油气运移有效驱动力,缓慢减小到由净浮力梯度与排驱压力梯度二者之和为其油气运移有效驱动力的现今低压致密气藏。与之相对应,高压致密古气藏由较小成藏期地层倾角窗口(0.2°~0.3°)缓慢变为现今低压致密气藏相对较大成藏期地层倾角窗口(0.35°~0.45°)。Scholars at both the domestic and foreign are mostly confined to the statistical analysis of exploration practice and simple physical simulation experiments when studying the relationship between stratigraphic dip and hydrocarbon resources during hydrocarbon accumulation period.There is a lack of research on the theoretical relationship between stratigraphic dip and hydrocarbon resources during hydrocarbon accumulation period.Based on the principle of minimum energy dissipation rate of oil and gas migration,the existence of stratigraphic dip window of hydrocarbon migration and accumulation system is strictly proved during hydrocarbon accumulation period.It has been shown that when the stratigraphic dip window is in the hydrocarbon accumulation period,the effective driving power of hydrocarbon migration is the weakest,the energy dissipation rate of hydrocarbon system is the lowest,the hydrocarbon migration and accumulation efficiency is the highest,and the amount of hydrocarbon resources reserved is the greatest.This study resolves the puzzle of why the amount of hydrocarbon resources on 44 natural gas effective zones and 49 oil effective zones that have been put into commercial development in China by Hou et al.(2021),and the average stratigraphic dip in the main hydrocarbon accumulation period exhibit the statistical characteristic of“downward parabola of opening”and explains the influence of stratigraphic dip size of hydrocarbon accumulation period on oil-gas reservoir formation.At the same time,this theory is used to study the evolutionary change of the stratigraphic dip window of tight gas reservoirs in the Upper Paleozoic of the Ordos Basin.The Upper Paleozoic high-pressure tight paleo-gas reservoirs,where the sum of net buoyancy gradient,excess-pressure gradient,and discharge pressure gradient is the effective driving force of hydrocarbon migration,gradually change to the modern low-pressure tight gas reservoirs,where the sum of net buoyancy gradient and discharge pressure gradient is the effective driv

关 键 词：油气运移最小能耗率原理 成藏期地层倾角窗口 鄂尔多斯盆地 低压致密气藏 气藏调整 

分 类 号：TE122.2[石油与天然气工程—油气勘探]