【摘要】 研究了鄂尔多斯盆地上古生界气田地下流体动力场演化和流体动力场特征以及与气水分布的关系,获得了气田流体动力学和天然气藏多方面的认识。盆地北部和东部上倾地区发育大气水下渗—向心流。盆地西南部下倾区为天然气聚集区。多数气藏内部能量亏损,天然气处于滞流状态。中间过渡带为天然气越流漏失区,气水共存。在盆地沉积埋藏阶段,天然气运移进入储层并溶解于地层水中,流体压力不断增强,发育地层压实水离心流。在天然气随离心流运移过程中,部分天然气游离,往储层上翘一侧漏失。随着天然气的漏失作用,地层流体压力不断降低,天然气和地层水几乎处于滞流状态。随着喜山期的沉积埋藏作用,处于封闭和滞流状态的气藏逐渐出现能量亏损,地层流体低压进一步发育。更多还原

【Abstract】 The oil and gas migration and accumulation ar e closely related to the formation and evolution of underground fluid dynamic fi eld. The Upper Paleozoic tight gas reservoir in E’erduosi Basin was formed unde r the back-ground of westward low-angle inclination. The centripetal flow indu ced by meteoric water permeating downwards is developed in the stratigraphic upd ip regions along the northern and eastern basin edges, where the water was produ ced. But the stratigraphic downdip region in the southwest part of the basin is the stagnant area of gas accumulation, where the gas was produced. The gas is in the stagnant condition because of deficiency in energy in most gas reservoirs. The intermediate zone between both of them is the loss zone of gas override flow , where the gas coexists with the water. In the sedimentary and buried stage, th e natural gas was dissolved into and migrated with formation water, and, at the same time, the centrifugal flow induced by sedimentary compaction occurred along with the increase in fluid pressure. In the course of gas migration with the ce ntrifugal flow, part of gas was escaped from the formation water and moved to th e upwarp portion of the reservoir. Along with the escape of gas, the formation p ressure decreased unceasingly, and the gas and formation water almost kept stagn ant. Because of the sedimentation and burial in Himalayan epoch, the deficiency in energy occurred gradually in the gas reservoir being in sealing and stagnant conditions and the formation pressure became lower and lower.更多还原