顺宁油田长21低渗砂岩储集层非均质性特征及其开发意义

鄂尔多斯盆地顺宁油田长2^1低渗砂岩储集层具有较强的非均质性，致密夹层比较发育，渗透率剖面属正、反韵律复合型；非均质性呈现纵向强于横向、河道边侧部强于河道主体、长2^1-2层强于长2^1-1层的规律。分析认为，微观非均质性是制约储集层渗透性的关键，沉积相带和成岩作用对储集层非均质性控制明显，非均质性对油气分布及注采剖面有重要的约束和影响；致密夹层能够有效地阻挡流体的纵向渗透，约束层内渗流，并阻止人工裂缝的穿层延伸，有利于集中水驱能量，提高水驱效率和储量动用程度，是划分开发小层、编制注水开发方案的重要依据。图5表3参17

Aeolotropism and its exploitation significance of Chang 21 low permeability sandstone reservoir of Yanchang Formation, Shunning Oilfield

Synthetic analysis of the aeolotropism and oiliness of Chang 21 reservoir bed in Shunning Oilfield,Ordos Basin reveals: the reservoir has serious aeolotropism,developed compact interlayers,and permeability sections with the normal-abnormal rhythmicity;The aeolotropism is more serious vertically than horizontally,in river sides than in river body,and in Chang 21-2 reservoir bed than in Chang 21-1.Microsopic heterogeneity is the key factor restricting reservoir's permeability.Sedimentary facies belt and diagenesis obviously control the permeability,which influences the oil-gas distribution and water injection profile or production profile.The compact interlayers in Chang 21 can effectively block vertical seepage of liquids,restrict intralayer seepage,and stop artificial cracks from breaking through.They are favorable to collecting water drive energy,increasing water drive efficiency and reserves utilization degree,and are the important basis for dividing exploitation members and working out water-injection development plan.