烃源岩孔隙流体介质对石油初次运移的影响

Effect of fluid medium in source rock porosity on oil primary migration

马中良 郑伦举 赵中熙 葛颖 徐勤

Ma Zhongliang Zheng Lunju Zhao Zhongxi Ge Ying Xu Qin

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126 2. 中国石化集团公司 油气成藏重点实验室, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, Wuxi, Jiangsu 214126, China 2. SINOPEC Key Laboratory of Petroleum Accumulation Mechanisms, Wuxi, Jiangsu 214126, China

利用自主研制的地层孔隙热压生排烃模拟仪,系统开展了氮气—水蒸气、水蒸气—液态水体系、液态水和无水体系系列生排烃模拟实验,通过对排油效率的分析对比,探讨了烃源岩孔隙流体介质对石油初次运移的影响.在生油气阶段,烃源岩孔隙空间是保持一定温度和压力的多组分(烃气、非烃气、石油、地层水)流体共存的一种相态.液态地层水是石油初次运移过程中不可缺少的运移载体.水可能是首先吸附在岩石矿物的表面,起到了一种"润滑剂"的作用,阻止了石油在矿物表面的吸附,从而有利于石油的运移.同时,生油气过程中伴生的大量的CO2,由于其独特的超临界特性,易于溶解孔隙流体中的石油,降低了油水之间的界面张力和石油的黏度,减小了石油运移阻力,促进了石油的初次运移.

With the self-designed simulation instrument for hydrocarbon generation and expulsion in formation porosity under controlled heating and pressuring conditions, a series of experiments was made with different systems such as nitrogen-water vapor, water vapor-liquid water, liquid water, and anhydrous. Oil discharge efficiency was compared to study the effect of the fluid medium in source rock porosity on oil primary migration. In the oil and gas generation phase, pore space in the source rock was charged by fluids (hydrocarbon gas, non-hydrocarbon gas, oil, formation water) with certain temperature and pressure. Liquid water was an indispensable transport carrier in oil primary migration process. Water might adsorb onto the surface of minerals, preventeding the adsorption of hydrocarbon and was favorable for hydrocarbon migration. CO2 associated with hydrocarbon generation easily dissolved in oil, which reduced the interfacial tension between the oil and water, oil viscosity and oil migration resistance, and promoted oil primary migration.

中国石化科技开发部项目"烃源岩有限空间生排烃机理研究与应用"(P11060)、国家重点基础研究发展计划(973计划)项目专题"陆相页岩油储集空间与发育模式"(2014CB239102)和"陆相页岩油资源潜力与分布规律"(2014CB239105)资助.

https://doi.org/10.11781/sysydz201501097