岩壁纳米孔隙内页岩油气赋存状态研究OA
Study on occurrence state of shale oil and gas in nanopores of rock surface
页岩油气广泛分布于油页岩纳米孔隙内,壁面赋存状态是破坏其连续性特征的关键,这种小尺度效应让其开采犹如在毛细血管采血,直接影响开采效率.因此,应用分子动力学建立了多级退火模拟耦合热裂解的成烃演化方法,通过裂解产物权重分析建立了与实际质量密度一致的页岩油气模型;同时通过真实岩壁特性分析得到了粗糙干酪根和羟基化石英壁面;基于壁面模型和页岩油气模型耦合进行了复杂地质环境下页岩油气与岩壁界面效应的赋存状态研究.结果表明,页岩油气在纳米孔隙中的质量密度分布存在显著差异.在干酪根纳米孔隙中,页岩气分子主要集中在孔隙中央,而在石英纳米孔隙中,页岩气分子分布于孔隙中央及靠近壁面的区域.随着孔隙尺寸增大,第1吸附层的质量密度峰值逐渐趋于饱和,且干酪根纳米孔隙的吸附层数明显高于石英.热裂解过程中的温度对页岩油气产物组成产生显著影响,尤其是在2 200 K的高温条件下,页岩油气的目标产物占比显著提高.在此温度下,龙口油页岩的热裂解产物中,C1(甲烷)、C6(己烷)和C12(十二烷)的比例接近12∶1∶1,说明高温对页岩油气的生成具有重要影响.此外,壁面特性对页岩油气的赋存状态和开采效率产生关键影响,粗糙的干酪根壁面和羟基化石英壁面对气体的分布与吸附行为产生不同程度的影响,进一步影响了油气的释放与开采过程.
Shale oil and gas are widely distributed in oil shale nanopores.Their occurrence state on the rock surface is crucial in disrupting the continuity characteristics.This small-scale effect makes shale oil and gas recovery like blood sampling in capillaries,which directly affects the efficiency of shale oil and gas recovery.Therefore,molecular dynamics was used to establish a hydrocarbon evolution method of multi-stage annealing simulation coupled with thermal cracking.A shale oil and gas model consistent with the actual density was achieved through cracking product weight analysis.At the same time,rough kerogen and hydroxyl quartz surfaces were obtained through analysis of real rock surface characteristics.Based on the coupling of the surface model and shale oil and gas model,the occurrence state of the interface effect between the shale oil and gas and the rock surface in a complex geological environment was studied.Research shows that there are significant differences in the density distribution of shale oil and gas in nanopores.In kerogen nanopores,shale gas molecules are mainly concentrated in the center of the pores,while in quartz nanopores,gas molecules are distributed in the center of the pores and near the surface.As the pore size increases,the density peak of the first adsorption layer gradually becomes saturated,and the number of adsorption layers in kerogen nanopores is significantly higher than that of quartz.The temperature during the thermal cracking process has a significant impact on the composition of shale oil and gas products.Especially under high temperature conditions of 2 200 K,the proportion of target products in shale oil and gas increases significantly.At this temperature,the ratio of C1(methane),C6(hexane),and C12(dodecane)in the thermal cracking products of Longkou oil shale is close to 12∶1∶1,indicating that high temperature has an important role in the generation of shale oil and gas.In addition,surface characteristics have a key impact on the occurrence state and recovery efficiency of shale oil and gas.The rough kerogen surface and hydroxylized quartz surface have varying degrees of impact on the distribution and adsorption behavior of gas,further affecting the release and recovery of oil and gas.
方威;卢艳;李劢;曹立范;李晨龙;高润
武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081武汉科技大学 冶金装备及其控制教育部重点实验室,湖北 武汉 430081||武汉科技大学 机械传动与制造工程重点实验室,湖北 武汉 430081
能源科技
分子动力学模拟热裂解成烃演化纳米孔隙赋存状态
molecular dynamics simulationthermal crackinghydrocarbon evolutionnanoporeoccurrence state
《油气地质与采收率》 2026 (2)
48-60,13
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