耐高温高矿化度海水基压裂液体系研究及应用

为满足海上高温低渗油田压裂施工的需求,以丙烯酰胺、丙烯酸、N-乙烯基吡咯烷酮和长链季铵盐阳离子单体为原料,制备了一种新型两性离子型聚合物稠化剂CHY-2,并以此为主要处理剂,研制了一套适合海上高温低渗油田的耐高温高矿化度海水基压裂液体系。该压裂液体系具有良好的耐温耐剪切性能,在160℃,170 s-1的剪切速率下实验120 min后,体系黏度仍能保持在100 mPa·s以上;压裂液基液具有良好的耐盐性能,使用105000 mg/L的模拟水配制的基液黏度较高。此外,该压裂液体系还具有较好的滤失性能、悬砂性能和破胶性能,并且破胶液对储层天然岩心基质渗透率的伤害率小于10%,具有较好的低伤害特性,能够满足海上油田压裂施工的要求。现场应用结果表明,海水基压裂液配制过程简单,性能稳定,X-11井压裂施工过程顺利,压后日产油量18.3 t,取得了良好的压裂施工效果。

RESEARCH AND APPLICATION OF HIGH TEMPERATURE AND HIGH SALINITY SEAWATER BASED FRACTURING FLUID SYSTEM

In order to meet the requirements of fracturing operation in offshore high temperature andlow permeability oilfield,a new amphoteric polymer thickener CHY-2 was prepared from acrylamide,acrylic acid,N-vinyl pyrrolidone and long-chain quaternary ammonium salt cationic monomer as raw materials,and a set of high temperature resistant and high salinity seawater based fracturing fluid system suitable for offshore high temperature and low permeability oilfield was developed.The fracturing fluid system has good temperature resistance and shear resistance,and the viscosity of the system can still be maintained at 100℃after 120 min test at a shear rate of 170 s-1.The results show that the base fluid of fracturing fluid has good salt resistance,and the viscosity of base fluid prepared with 105000 mg/L simulated water is higher;in addition,the fracturing fluid system also has good filtration performance,suspended sand performance and gel breaking performance,and the damage rate of gel breaker to the permeability of natural core matrix is less than 10%,which has good low damage characteristics,and can meet the requirements of offshore oilfield fracturing Requirements of workers.The field application results show that the preparation process of seawater based fracturing fluid is simple and its performance is stable.The fracturing process of well X-11 is smooth,and the daily oil production after fracturing is 18.3 t,which has achieved good fracturing effect.