摘要
鉴于胍胶压裂液破胶不彻底、残渣含量高，活性水压裂液流变性能差的缺点，研制了以非离子聚丙烯酰胺聚合物（A-1）作为稠化剂、有机锆（G-1）作为交联剂的冻胶压裂液，考察了pH值、温度、交联比（交联剂与基液体积比）和矿化度对有机锆冻胶压裂液的影响。优选出了有机锆冻胶的典型配方：0.5%A-1+2.5%G-1，并对该配方进行了性能评价。结果表明，锆冻胶压裂液具有低滤失、易破胶、悬砂性能好的特点，在90℃下，初始滤失量仅为16.41×10-3 m3/m2，滤失系数为6.66×10-4m/min1/2，在剪切170 s-1下剪切2 h后的黏度仍保持在50 mPa·s以上，破胶液对岩心的损害仅为14.88%，适于低渗透油气藏的改造。
Abstract
As the limitations of high content of water insoluble substance and high residual content to the gum fracturing fluids and poor rheological property to the active water fracturing fluids, the article studies a new fracturing fluid was studied using a nonionic polyacrylamide (A-1) as the thickening agent and organic zirconium (G-1) as the cross-linking agent. By investigating the gelation time, the formulation of the fracturing fluid adapted to site operation was optimized as follows: 0.5%A-1+2.5%G-1, and the effects of different factors, such as pH value, temperature, volume ratio of crosslinker to based liquid and salinity, on performance of the zirconium gel was analyzed. The evaluation tests showed that the aqueous zirconium gel was suitable to low permeable oil reservoir. The fracturing fluid had characteristic of low filtrate loss, little residue of the gel-breaking and good capability of transporting sand. The initial filtration rate was only about 16.41×10-3 m3/m2 and the filtration coefficient was 6.66×10-4m/min1/2at the temperature of 90℃. The zirconium gel possessed shearing resistance, the viscosity remained above 50mPa·s after sheared at shear rate of 170 s-1 for two hours. The damage of gel-breaking liquid to the formation was 14.88% and the gel breaking liquid was easy to flow back.
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