中高温清洁压裂液体系PA-VES120的研发

Development of medium-high temperature clean fracturing fluid PA-VES120

为提高清洁压裂液的耐温性能,通过实验合成了阳离子双子表面活性剂PA-S18,并利用红外光谱和核磁共振技术对其分子结构进行了表征。以PA-S18为主剂,配制了中高温清洁压裂液体系PA-VES120,并对其耐温抗剪切性能、破胶性能及对地层伤害程度进行了实验评价,结果表明:该体系在120℃、170 s^(-1)下剪切60 min,粘度保持在40 mPa·s以上,可满足悬砂性能要求;该体系破胶简单,利用2%的原油、柴油、混苯作为破胶剂,2 h内均能完全破胶;该体系对岩心基质渗透率损害率和动态滤失渗透率损害率均在10%左右,对地层伤害较小。PA-VES120清洁压裂液体系的成功研发,对于提高海上低渗油气藏中高温地层压裂增产效果具有重要意义。

In order to increase the temperature resistance of clean fracturing fluid,a type of cationic bimolecular surfactant PA S18 was synthesized and the molecular structures of the product were characterized by the IR and NMR.The medium-high temperature clean fracturing fluid system PAVES120 has be made up by using PA-S18 as main agent.The properties of resistance to high temperature and shearing,gel breaking,and formation damage were evaluated in the lab.The evaluation results show that PA-VES120 fracturing fluid system is sheared by 60min at 120℃ and 170s^-1,with the viscosity kept higher than 40 mPa· s,which meets the requirements for proppant carrying capacity; the system breaks gel simply and completely in 2 h by using 2% crude oil,diesel and mixbenzene as gel breaker; and the system damages the core permeability and dynamic filtration permeability both within 10%,showing little damage to formation.The successful R ＆ D of PA-VES120 has great significance for improving the fracturing effect in the low permeability and medium-high temperature oil gas reservoir in offshore fields.