油气成藏“相—势”耦合作用探讨——以渤海湾盆地济阳坳陷为例

STUDY OF FACIES AND POTENTIAL COUPLING EFFECT IN OIL AND GAS POOL FORMATION——A CASE STUDY IN THE JIYANG DEPRESSION, THE BOHAI BAY BASIN

王永诗

Wang Yongshi

中国石油化工股份有限公司, 胜利油田分公司, 地质科学研究院, 山东, 东营, 257015

Research Institute of Geological Sciences, Shengli Oil Field, SINOPEC, Dongying, Shandong 257015, China

渤海湾盆地济阳坳陷的勘探实践表明,同一成藏动力条件下,油气充注成藏过程中油气等流体突破储层进/出口界面的抵抗力(突破压力)存在差异,导致选择性地进入储集体和孔隙.将油气的这种突破作用和选择性充注归因于储层介质属性(相)、流体流动能力(势)和两者之间的耦合作用,重点探讨其作用机制,建立"相—势"耦合控藏模型,揭示储层有效接纳油气的临界条件,指出随着油层变浅,远离烃源岩,浮力和烃源岩剩余排替压力降低,油水界面张力增加,储层介质接纳油气的临界渗透率和临界孔隙度逐渐变大,从而建立油气成藏的临界条件预测模型,进一步丰富断陷盆地油气勘探理论与方法.

Exploration practices in the Jiyang Depression of the Bohai Bay Basin have indicated that,under the same dynamic condition of oil and gas pool forming,resistivity(breakthrough pressure) of entrance and exit interface is different,so fluid enters reservoir and pore respectively.It is caused by reservoir property(facies),fluid dynamics(potential) and their coupling effect.Mechanism of the effect is discussed and pool-controlling model is set up.Critical terms for reservoir to hold oil and gas are pointed out.As reservoir getting shallow and far away from source bed,buoyancy and residual entry pressures of source rock reduce,oil-water interface tension increases,and critical permeability and porosity for reservoir to hold hydrocarbon gradually increase.Thereby,critical qualification forecast model of pool forming is set up to enrich exploration theory and method in continental fault basins.

国家“十五”重大科技攻关项目(2001BA605A09)

https://doi.org/10.11781/sysydz200705472