Abstract: Using natural sandstone core samples,the effect of wettahlity alteration of reservoirrocks caused by oil-based mud on water flood behavior was studied through establishingmodels of reservoir rocks and simulating the processes of the mud filtrate invasion,displace-ment restoration and water flooding.The test results showed that the increased rate of watercut raised,and both the recovery efficiency and oil production are substantially reduced afterthe sandstOne core were altered from water-wet to oil-wet.It was found that oil-based mudwith stronger oil-wet behavior had more significant effect on recovery efficiency,indicatingthat wettability reversal is an important mechanism of formation damage induced by oil-based completion fluids,Meanwhile,a comparison study on water-based mud and their com-ponets of water flood behavior has been conducted.

Key words: oi-based mud, rock, wettability, oil displacement efficiency, formation damage

摘要： 使用天然砂岩岩样,通过建立油藏岩石模型和模拟泥浆滤液侵入油层、恢复驱替、水驱等过程,研究了油基泥浆引起的油藏岩石润湿性改变对水驱油动态的影响.试验结果表明,当水湿砂岩转变为油湿之后,模型的含水上升率增大,驱油效率和产油量明显下降.并发现油湿作用较强的油基泥浆对驱油效率的影响更为显着,从而表明润湿反转是油基完井液对储层造成损害的一个重要机理.与此同时,对水基泥浆及其组分影响水驱油动态的情况也进行了对比研究.

关键词: 油基泥浆, 岩石, 润湿性, 驱油效率, 地层损害