一种新型添加剂在玉门油田化学驱先导性试验中的应用

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.

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

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.