利用储层成垢离子物源实现优势通道调整提高水驱效率

Improvement of Water Flooding Efficiency by Using the Reservoir Forming Ion Source to Realize the Adjustment of the Dominant Channel

为了解决CaCl_2水型油田地层水的高矿化度对深部液流转向剂性能的负影响,降低转向剂成本,进而实现降本增效的目的,本文研究了一种由多种无机材料经特殊工艺加工合成的复合硅酸盐微凝胶转向剂OMGL在CaCl_2水型油田高矿化度地层水中的凝胶性能、封堵转向性能及现场应用情况。该转向剂主要利用高矿化度地层水(注入水)中的Ca2+、Mg2+作为交联剂发生交联反应。室温下,0.6%OMGL在油田水中凝胶化反应在12~24h内完成;随着OMGL浓度升高,体系的凝胶化程度增高,组分为3%OMGL+1%CaCl_2水溶液体系的凝胶化程度达100%。OMGL与地层水中的Ca^(2+)、Mg^(2+)发生凝胶反应形成的粒径0.05~2μm的微凝胶,对低渗小孔基质进入困难,而在优势通道岩石骨架表面通过—Si—O—Si—键形成稳定的微凝胶涂层。转向剂OMGL对渗透率级差在10~50倍范围岩心的调堵效果比较理想。该转向剂已在国内外不同温度不同矿化度条件油藏开展深部调驱现场试验,改善水驱效果良好,注水压力平均升高2~3 MPa,对应油井增油效果良好,有效期在1年以上。

In order to solve the negative influence of the high salinity of formation water on the performance of the deep liquid flow divertring agent in the CaCl2 water type oilfield, reduce the cost of the steering agent, and then achieve the purpose of reducing the cost and increasing the efficiency, the gel performance, plugging and diverting performance and field application of a composite silicate microgel diverting agent OMGL, synthesized by a variety of inorganic materials through special processes, in the CaCl2 water type formation water was discussed. The diverting agent OMGL reacted with Ca^2＋ and Mg^2＋ in high salinity formation water （injected water）. The gelation reaction of 0.6%OMGL in oil field water completed within 12--24 h at room temperature. With the increase of OMGL concentration, the gelation degree of the system increased and the gelation degree of the 3%OMGL＋ 1%CaCl2 aqueous solution system was 100%. The microgel with particle size of 0.05--2μm was formed by the gel reaction of OMGL with Ca^2＋ and Mg^2＋ in the formation water, which was difficult to enter the low permeability microporous matrix, and a stable microgel coating was formed through the --Si--O--Si-- bond on the surface of the rock skeleton of the dominant channel. The diverting agent OMGL was ideal for plugging the core with a permeability ratio of 10 ~ 50 times. This kind of diverting agent had been carried out in the field experiments with different temperatures and different salinity conditions at home and abroad, the effect of the enhancement of oil recovery of water flooding was good, the water injection pressure increasing by 2--3 MPa, and the oil increasing effect being good and the effective period being over 1 years.