摘要
安塞油田王窑区经过20多年的注水开发,储层有不同程度水淹,长期的水驱冲刷引起储层微观特征改变。针对不同水淹区域部署检查井进行储层微观特征变化及机理研究,对检查井密闭取心资料的分析研究表明:强水淹层段储层的粒度粗,面孔率高,孔喉结构较均匀。在强水淹层段有新生矿物方解石的生成,与原生矿物有明显区别。与注水开发前原始储层相比,储层粘土矿物的迁移及新生矿物的产生,导致注水开发后储层的物性变差。注水开发中后期储层吼道中值压力增加,退汞效率降低,相渗曲线变差,水驱油效率降低。
Through more than 20 years＇ water flooding development, the microscopic characteristics of reservoirs in Wangyao Area of Ansai Oilfield have been changed in some degree due to long-term water flooding and washing. In order to investigate the changing mechanism of formation characteristics, inspection wells are deployed in different water flood areas, and sealing core data from these inspection wells are analyzed. Results have shown that reservoirs which are strongly watered out have coarse granularity, high surface porosity and good pore throat structure. Besides, neogenic calcite which is obviously different from the original mineral is generated in these intervals. Compared with the initial formation before water driving, physical properties of water flooded reservoirs get worse because of the migration of clay mineral and generation of new minerals. The effects of water flooding mainly show up in the increased median pressure of reservoir throat during the middle and late stage of water flooding. There is lower mercury withdrawal efficiency and poorer relative permeability curve, which decreases the displacement efficiency of water flooding.
出处
《西北地质》
CAS
CSCD
2013年第3期183-190,共8页
Northwestern Geology
基金
大型油气田及煤层气开发重大专项"鄂尔多斯盆地大型岩性地层油气藏勘探开发示范工程"(2008ZX05044)
关键词
储层微观特征
新生矿物
粘土矿物
水淹层
渗流特征
microscopic characteristics of reservoirs
neogenic minerals
clay mineral
water flooded layer
percolation characteristics
