鄂尔多斯盆地红河油田长8油藏天然裂缝特征及其对开发的影响

Natural fracture characteristics of Chang 8 reservoir in Honghe oilfield of Ordos basin and its influence on development

鄂尔多斯盆地红河油田长8油藏是典型的致密砂岩油藏,其储层物性差,天然裂缝发育,实践证明,断层、裂缝的发育程度对红河油田油气富集和高效开发具有重要作用。针对红河油田长8储层裂缝的特征、类型、成因进行精细刻画,阐明储层裂缝形成机理和分布规律;通过系统分析长8储层裂缝与油气富集之间的关系,厘清储层裂缝对红河油田长8油藏开发动用的影响。研究表明,红河油田长8储层裂缝发育,但有效性较差;天然裂缝是长8储层的主要储集空间和渗流通道,是控制油井产能的关键因素,也是油藏注水开发效果的重要影响因素。其中,断层端部、断层上盘和断层之间的裂缝发育区是高产有利区。

Chang 8 reservoir of Honghe oilfield in Ordos basin is a typical tight sandstone reservoir with poor physical properties and developed natural fractures.The exploration and development practice for many years has proved that the development degree of faults and fractures plays an important role in oil and gas enrichment and efficient development of Honghe oilfield.According to the fracture characteristics,types and genesis of Chang 8 reservoir in Honghe oilfield,the reservoir fracture is finely described,and the formation mechanism and distribution law of reservoir fracture are clarified.Through systematic analysis of the relationship between the fractures and the enrichment of oil and gas in Chang 8 reservoir,the influence of the fractures on the development and production of Chang 8 reservoir in Honghe oilfield is clarified.The results show that the fracture of Chang 8 reservoir in Honghe oilfield is developed,but its effectiveness is poor.Among them,fracture development areas at the end of fault,hanging wall of fault and between faults are favorable areas for high production.The natural fracture is the main reservoir space and seepage channel of Chang 8 reservoir,the key factor for controlling oil well productivity,and also the important factor for affecting reservoir water injection development.