一种新型添加剂在玉门油田化学驱先导性试验中的应用

THE APPLICATION OF A NEW ADDITIVE IN THE PILOT CHEMICAL FLOODING PROJECT IN YUMEN OIL FIELD

对于高粘土含量、地层水矿化度和硬度较高的油藏，在采用化学驱（如表面活性剂－聚合物驱、微乳状液驱、聚合物驱等）提高石油采收率时，为了保持驱油段塞的稳定性维持其在驱替过程中的最佳状态，通常是在注入化学剂段塞之前预光挤入碱水（或盐水）预冲洗油层。但是，这将拖长施工时间且花费昂贵。我们合成了一种有机高分子化合物（商业代号ＢＰＡ），将其直接加入到化学体系中，对驱油体系的界面性质、相行为、溶液性质、配伍能力、渗流和驱油试验等系统试验研究表明，所得到的驱油体系性能优于传统使用的驱油体系；在不进行预冲洗的情况下，加入ＢＰＡ的驱油体系配方可以得到较高的驱油效果。其作用机理是：（１）增加岩石粘上表面的Ｚｅｔａ电势（负值）；（２）络合多价金属阳离子；（３）增强表面活性物质的活性。在老君庙油田Ｌ油层进行的现场试验表明，在注入加有ＢＰＡ的驱油剂之后，注入井的注入压力（保持们同注入量）下降１４．４％～１７．８％，其吸水率上升了２７０％，导流系数上升１９０％，表面活性剂的吸附量明显降低。

Traditionally preflush by dkdine and salty water have been used in conjunction withchemical flooding for maintaining optimum state of reservoirs with high clay and high salini-ties.However,all preflushes tend to prolong the time as well as to increase the expenditures.We have synthesized a high molecular weight polymer,BPA which can be introduced to thechemical flooding formulation directly. This will eliminate any preflush requirement.The na-ture of this technique is as follows:1.increase the negative values of Zeta potential,2.complexation of muItivalent cations,3.increase interfacial activity of surfactant.The technique is su-perior when compared with the traditional formulation. Field experiment at Laojunmiao ind-cated the following:injection pressure, lowered from 14.4%-17.8%, water imbibition,in-creased 270%,mobility ratio increased 190%,adsorption of surfactant greatly lowered.