柔性转向剂深部液流转向机理

Deep fluid diverting mechanism of soft diverting agent

柔性转向剂化学稳定性高,单轴抗拉、抗压缩实验表明柔性转向剂可任意变形,韧性好、不易破碎断裂。一维孔喉模型实验表明柔性转向剂的门槛压力与喉粒径比呈指数关系,当地层压差大于柔性转向剂的门槛压力时,柔性转向剂运移;否则柔性转向剂停留在地层中。网络模型实验表明,柔性转向剂颗粒通过弹性变形、塑性变形、造粒、粘连4种形式交替运移,并以"散兵"式分布在地层微小孔喉处,通过叠加原理形成暂堵蠕动带实现对地层的全程调剖并最终停留在地层深部实现深部液流转向。王官屯油田官74区块柔性转向剂调剖现场试验取得了预期效果,说明柔性转向剂可有效解决高含水油田开发后期大量注入水沿油水井间大孔道无效循环、注入水波及效率较低的问题。

Soft diverting agent features high chemical stability. Uniaxial extension and compression tests indicate that the agent could be deformed randomly and hard to be broken for its high tenacity. 1D pore throat model tests indicate that there is an exponential relationship between threshold pressure of the agent and throat-particle diameter ratio. If the formation pressure differential is higher than the threshold-pressure, the agent can move; otherwise, the agent will remain in the reservoir. Network model test indicates that the particles of the agent migrate alternatively in four forms： elastic deformation, plastic deformation, grain generation and grain conglutinating, and are distributed at microthroats in the formations like skirmishers, thus forming a temporary plugging peristalsis strip through overlapping to realize the wholeprocess profile control over the formation and finally settle at the deep section of the reservoir, so the diverting of deep fluid is completed. The field test of Guan74 block in Wangguantun Oilfield, with expected results obtained, illustrated that the soft diverting agent can overcome the problems of inefficient circulating of injected water in large pore channels between oil and water wells and of the low sweep efficiency in late development of high water cut oilfields.