分子膜(MD)在岩石粉表面的吸附特征及提高采收率研究

Study on the Adsorption Characteristic of Molecular Diaphragm(MD) on Rock Powder Surface and Enhanced Oil Recovery

分子膜驱油技术因其操作运用简单、不伤害储层、价格便宜等优点而成为提高油田采收率的重要方法之一。采用紫外分光光度计法研究了分子膜(MD)在陆梁油田白垩系呼图壁河组岩石粉上的静态吸附特征以及在模拟岩心中的动态吸附规律,采用Zetasizer2000研究了分子膜(MD)吸附在石英砂表面的Zeta电位变化;并进行了分子膜(MD)室内驱油实验研究。研究结果表明:1分子膜(MD)在岩石粉上12 h后吸附可达到平衡,吸附量受液固比、膜剂浓度影响,动态吸附特征曲线可分为3个阶段;2分子膜(MD)吸附在石英砂表面后会提高石英砂表面的Zeta电位,使石英砂表面呈电中性或弱正电性;3分子膜(MD)驱可降低注入压力及后续水驱注入压力,总体采收率在水驱的基础上再把采收率提高8%左右。

The molecular diaphragm( MD) floodingis one of the important methods to enhance oil recovery because of its high displacement efficiency、harmless reservoir、low-cost. Static adsorption characteristic of the molecular diaphragm( MD) on rock powder in Luliang oilfield of Hutubi river group of cretaceous and dynamic adsorption rule in simulated core is studied by using the UV spectrophotometer. The Zeta potential change of quartz sand with molecular diaphragm( MD) concentrations is studied by using the Zetasizer2000. Finally,using the molecular diaphragm( MD) laboratory displacement experiment is conducted. The research result shows that: Firstly,adsorption can be balanced when the adsorption time up to 12 h,and the amount of adsorbance was related to the solid to liquid ratio and its concentration,and the curve of dynamic adsorption rule can be divided into three stages. secondly,Zeta potential of quartz sand will rise so that the quartz sand are electrically neutral or weakly electropositive when the molecular diaphragm( MD) be absorbed on quartz sand. Lastly,molecular diaphragm( MD) flooding can reduce injection pressure and injection pressure of subsequent water flooding,and it can improve the recovery ratio of the water flooded crude oil by 8%.