【作者】 张守春；

【导师】 查明；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2010， 博士

【摘要】 本论文充分吸收前人的研究成果,结合大量的实际资料对东营凹陷异常高压的形成机制进行了系统的分析,认为欠压实、生烃增压、地层剥蚀对流体增压有显著作用。但是由于增压机制的阶段性差异,对油气运移有影响的机制主要有生烃增压及地层剥蚀作用。根据对东营凹陷盆地演化史的分析,认为在东营运动末期地层抬升剥蚀之前异常压力的形成以欠压实为主,而在剥蚀之后以生烃增压为主;在明化镇末期又发生了一次剥蚀,造成压力场的变化而诱发流体运移。为定量地研究压力条件对烃源岩生烃演化的影响程度,本次通过开放体系和封闭体系的模拟实验,根据生烃动力学的原理进行了对比分析。认为压力对烃源岩的生烃过程具有不同程度的抑制作用,主要表现在对不同类型的烃源岩及在不同的演化阶段,其影响均有所不同;随母质生烃潜力的增大、演化程度增大、地层压力增高的情况下,抑制作用越发明显。根据实验结果,确定了四套烃源岩在演化过程中有压力条件存在的生烃动力学参数。进行了填砂和岩芯两种介质条件的油气运移模拟实验,并采用增压和卸压方式以控制动力条件的变化。在增压过程中压力首先驱动水运移,储层中的烃类逐渐富集,岩样中的含油饱和度达到一定程度时才可以促使油运移。在卸压过程中,有气体存在时,其快速膨胀可导致油、气、水大量快速涌出,该情况下的卸压条件利于油气的运移。通过对东营凹陷重要地质历史时期剩余流体压力场的分析,现今油藏总体沿剩余流体压力降低的方向分布,表现出油藏的分布与流体压力的演化具有一定的继承性。流体压力的发育从整体上影响了油藏的形成,反过来油气运移和成藏也影响了流体压力场的分布。由于增压-卸压的平衡关系,流体压力在传递过程中在不同压力系统中构成了不同的动力条件,造成了油气在成藏类型和特征上具有一定的差异性。根据剩余流体压力的演化史,分析了东营凹陷的成藏过程,油气成藏与盆地演化有密切的关系。生烃增压期油气充注不断地积累饱和度,而剥蚀期油藏进一步得以调整。更多还原

【Abstract】 On the basis of previous study and underground data, the forming mechanisms of abnormally high pressures are studied. It is concluded that the undercompaction, hydrocarbon generation and stratum denudation are obviously effective to fluid pressure buildup. Because of the episodic difference, the hydrocarbon generation and stratum denudation are the main factors influencing oil-gas migration. On the basis of basin evolutionary analysis in the Dongying Depression, it is considered that the undercompaction mainly caused the abnormal pressure before the first denudation by the uplift in Late Paleogene, while hydrocarbon generation was the main factor of abnormal pressure after the denudation. The second denudation occurred in Late Neogene, which changed the pressure field and induced fluid migration.Open- and closed-system simulation experiments were made to study the influence of pressure to hydrocarbon generation quantitatively. In conjunction with the analysis by the founded numerical model, some conclusions were made on the basis of the experiments. Pressure suppresses the hydrocarbon generation on different extents according to different source rocks and different evolutionary stages. The higher the hydrocarbon generation potential of mother materials, the higher the evolutionary degree and the higher formation pressures, the more evident the suppression of hydrocarbon generation. The kinetic parameters of hydrocarbon generation of the source rocks related to pressure were accordingly determined.Oil-gas migration experiments were performed with two kinds of media, i.e. filled sands and cores. Pressure difference was obtained to control the dynamic conditions. Pressure prior to drive water when increases. Oil becomes more and more abundant in reservoir gradually. Oil begins to migrate when its saturation get to certain extents. The mixture of oil, gas and water was expelled rapidly during pressure relief because of the existence of gas. Pressure relief makes it easy for petroleum to migrate with the existence of gas.The exess pressure fields were analyzed at critical geologic times. The present reservoirs distribute along excess pressure decreasing directions. The distribution of reservoirs is successional to the evolution of excess pressure. The development of fluid pressure affects reservoir formation as a whole, while oil-gas migration and accumulation affect the distribution of fluid pressure fields. Due to the equilibrium between pressure buildup and pressure relief, fluid pressure created different conditions in various pressure systems during its transference, which caused the differences in types and features of oil-gas reservoirs. Based on the evolutionary history of excess pressure, the reservoir forming process in the Dongying Depression was analyzed. Reservoir formation strongly correlated with tectonic activity at different stages. Oil and gas charged reservoirs to increase saturation at the stage in which pressure rises caused by hydrocarbon generation. The reservoirs were regulated during denudation.更多还原