胜坨油田二区沙二段83层储层润湿性变化及对开发效果的影响

胜坨油田二区沙二段80层经过数十年的注水开发，已进入特高含水开发阶段，储层润湿性发生了很大的变化。利用不同含水开发阶段检查井岩心分析资料及物理模拟和数值模拟等技术手段，研究了储层润湿性的变化规律，揭示了储层润湿性变化的机理，分析了润湿性变化对开发效果的影响。研究表明，长期注水冲刷使储层润湿性由弱亲水转变为亲水，而且随着含水率的上升，其亲水性逐渐增强；注水过程中束缚水剥蚀力和界面收缩力的增大是储层润湿性变化的主要原因；储层亲水性增强有利于剩余油的采出和最终采收率的提高，使开发效果变好。

Reservoir wettability change of the 83 stratum of Es2 in Block No.2 of Shengtuo Oilfield and its influence on development effect

The 83 stratum of Es2 in Block No. 2 of Shengtuo Oilfield has been in the extra high water cut stage for several decade wa-terflood development with great change on reservoir wettability. By using core analytical information of inspection chamber at different water cut stages, and several technical means such as physical and numerical simulation were applied to researching change rules of the reservoir wettability, the change mechanism of the reservoir wettability was discovered and the influence the wettability change on development results was analyzed. The results show that the reservoir wettability transformed from the hydrophobicity into hydrophilicity because of flushing by water injection for long time,moreover,the hydrophilicity was strengthened gradually with the rise of water cut. In the process of waterflooding, the increases of denudation force of irreducible water and interfacial shrinkage force was main reason of the change of the reservoir wettability. The strengthened hydrophilicity was advantageous to exploit remaining oil and to enhance the ultimate oil recovery, and improved the development effect.