过硫化物对压裂液破胶性能的实验研究

Experimental study on the fracture performance of the fracturing fluid by the over sulfide

针对过硫酸盐对压裂液破胶性能的问题,通过设计实验探究K_2S_2O_8对压裂液破胶性能的影响。考察过硫酸钾浓度、破胶温度等影响因素条件下,以破胶液表观黏度为5.0m Pa·s时所需的时间为破胶时间,研究过硫酸盐的破胶性能。深入分析了水基压裂常用的稠化剂羟丙基瓜胶的结构和过硫酸盐破胶的原理,温度影响K_2S_2O_8的分解速度,K_2S_2O_8的速率常数与半衰期的关系。并采用表观粘度、表面张力及残渣含量等表征实验,探究过硫酸盐破胶规律。实验结果表明:温度为60℃时,随着K_2S_2O_8破胶剂浓度增加,破胶时间缩短,破胶液粘度和表面张力逐渐降低。通过对比温度实验,温度为70℃时,压裂液越易破胶,破胶时间越短,粘度和表面张力降低,残渣含量相对降低越明显。

In view of the problem of the breaking performance of persulfate to fracturing fluid, the influence of potassium persulfate on the fracture property of fracturing fluid was studied through design experiment. Under the influence of factors such as the concentration of potassium persulfate and gel breaking temperature, the gel breaking time was studied when the apparent viscosity of the gel was 5.0mPa·s, and the gel breaking performance of the persulfate was studied. The structure of hydroxypropyl guar gum and the mechanism of persulfate gel breaking were analyzed in detail. The temperature affected the decomposition rate of potassium persulfate and the relationship between the rate constant of potassium persulfate and the half-life of persulfate. And the apparent viscosity, surface tension and residue content were used to characterize the experiment, he results show that the gel breaking time is shortened and the viscosity and surface tension of the breaker decrease with the increase of the coneentration of potassium persulfate breaker at 60℃. When the temperature is 70℃, the fracturing fluid is more easily broken, the shorter the gel breaking time, the lower the viscosity and the surface tension, and the lower the residue content.