烃源岩有限空间油气生排模拟及其意义

Simulation of source rock for hydrocarbon generation and expulsion in finite space and its significance

李志明 郑伦举 马中良 徐二社 余晓露 靳广兴 慕小水

Li Zhiming Zheng Lunju Ma Zhongliang Xu Ershe Yu Xiaolu Jin Guangxing Mu Xiaoshui

中国石油化工股份有限公司 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡, 214151 2. 中国石油化工股份有限公司 中原油田分公司 勘探开发科学研究院, 河南 濮阳, 457001

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China 2. Exploration and Development Scientific Research Institute, Zhongyuan Oil field Company, SINOPEC, Puyang, He'nan 457001, China

利用DK-Ⅱ型地层孔隙热压生排烃模拟实验仪,对东濮凹陷沙三2亚段烃源岩开展烃源岩有限空间油气生排模拟研究,结果揭示烃源岩的生排烃演化呈现出4个阶段,即烃源岩在Ro值小于等于0.72%的阶段为相对缓慢生油阶段,生成的油无法排出;Ro值介于0.72%～0.80%之间的阶段为烃源岩快速生油阶段,但生成的油仍主要残留于烃源岩中;在Ro值为0.80%～1.00%时干酪根生油已结束或受到抑制,主要表现为大分子"油"向小分子"油"转化,该阶段油可以排运在烃源岩上、下邻接的砂岩层以及烃源岩表面及裂缝内,这为东濮凹陷及其他盆地或凹陷在以烃源岩为主体的发育带寻找非常规油气藏提供了依据;在Ro值大于1.00%时主要进入油裂解成气阶段,但即使在Ro为2.0%甚至2.4%时,生成的油也没有全部裂解成甲烷气,主要还是以油的形式存在,启示可以打破传统认识在更深的层位寻找石油。

Simulation of source rock for hydrocarbon generation and expulsion in finite space has been carried out with samples from the Es23 sub-section of the Dongpu sag using the hydrocarbon generation and expulsion simulation experimental instrument of type DK-Ⅱ with porosity,temperature and pressure under geological conditions.It has been concluded that the process of hydrocarbon generation and expulsion of source rock can be divided into 4 stages as follows.1)Ro≤0.72%,oil generates slowly and does not expel;2)0.72% Ro 0.80%,oil generates rapidly,but still remains in source rock;3)0.80% Ro 1.00%,oil generation from kerogen has finished or suppressed,and oil transfers from big molecular to small molecular.Oil migrates to and assemblages in the upper and lower adjacent sandstone as well as source rock surface and fracture,which may guide unconventional hydrocarbon exploration in source rock dominant belt in the Dongpu Sag or the other similar basins or sags;4)Ro 1.0%,oil cracks to gas;however,oil does not crack to CH4 completely and mainly remains in oil even though Ro 2.0% or 2.4%.The studies suggest that petroleum exploration can be carried out in deeper formation.

中国石油化工股份有限公司科学技术研究开发项目(P08060)资助

https://doi.org/10.11781/sysydz201105447