油水两相同时流动出砂规律模拟试验

油气开采过程中，地层流体介质变化是油气井出砂的一个重要原因，水侵引起的出砂量急增可能会引起灾难性的后果。因此，研究水侵对地层出砂的影响，是进行合理的完井设计和油田开发中后期出砂管理的基础。针对油田生产过程中综合含水上升趋势．通过简易防砂室内模拟试验，系统分析了疏松砂岩油水两相同时流动情况下的出砂规律和出砂特征、不同油水比例下流量和出砂量的动态变化规律、产出砂粒粒度分布和蚯蚓洞形成情况。结果表明：出砂伴随着整个试验过程；岩样总出砂量随含水量的增加而增加；岩样出砂后流量有上升趋势，但在油水体积比较大时，可能由于发生砂拱破坏，试验过程中流量出现波动；试验后期均发生了岩样坍塌现象，表明出水会导致岩石骨架发生破坏，使出砂变得更加严重。

Laboratory Simulation of Sand Production Under Oil-water Simultaneous Flow in Unconsolidated Sand Pack

One factor that influences the onset of sand production is water breakthrough during the production of the reservoirs. The accumulative sand production coinciding with water can cause catastrophic problems. Based on the water content rising tendency in the oilfield, a series laboratory experiments has been performed to better understand sand production behavior of unconsolidated sandstone under different oil-water simultaneous flow conditions. The dynamic changes of flow rate, sand production rate and grain size distribution of produced sand with time and wormholes formed after the tests under different oil/water ratio have been systematically described. The influence of oil/water ratio on sand production and wormhole formation is analyzed. The experiment results demonstrated that accumulative sand production increases with the increasing of water content; production rate also increases after sand is produced; and water can cause serious sand production due to sand arch or wormhole collapse.