耐高温聚合物加重压裂液的开发及性能评价

Development and performance evaluation of high temperature resistant polymer weighted fracturing fluid

针对海上高温高压超深井储层改造过程存在摩阻大、施工压力高和压裂液耐高温性能差的问题,选用甲酸钾作为加重剂,开发耐盐稠化剂,形成密度为1.40g/cm^(3)耐温170℃的加重压裂液体系,同时开发出新型破胶剂,以解决常规破胶剂过硫酸铵破胶难的问题。对该体系的耐温耐剪切性能、降阻率、静态悬砂性能以及破胶液性能进行评价。结果表明,海水基加重压裂液在170℃、170s^(-1)条件下剪切120min,表观黏度保持在50mPa·s以上;加重压裂液降阻率为60%,破胶液的黏度为5mPa·s。破胶液残渣含量、表界面张力和岩心伤害都可满足SY/T 7627—2021行业标准要求。

In response to the problems of high friction,high construction pressure,and poor high-temperature resistance of fracturing fluids in the process of renovating high-temperature and high-pressure ultra deep reservoirs at sea,potassium formate was selected as a weighting agent,and a salt resistant thickener was developed to form a weighting fracturing fluid system with a density of 1.40g/cm^(3) and a temperature resistance of 170℃.At the same time,a new type of demulsifier was developed to solve the problem of difficulty in breaking the conventional demulsifier ammonium persulfate.The temperature and shear resistance,drag reduction rate,static sand suspension performance,and gel breaker performance of the system were evaluated.The experimental results showed that the seawater based pressurized fracturing fluid maintained an apparent viscosity of over 50mPa·s after shearing at 170℃ and 170s^(-1) for 120 minutes;The drag reduction rate of the enhanced fracturing fluid was 60%,the viscosity of the fracturing fluid was 5mPa·s,and the residual content,interfacial tension,and core damage of the fracturing fluid can all meet the requirements of the SY/T 7627—2021 industry standard.