一种延迟交联的抗高温加重胍胶压裂液的研究

深井储层埋藏深、岩性致密，破裂压力和裂缝延伸压力高，导致压裂施工压力高、难度大，常规压裂液密度低，无法保证施工安全和措施效果。为此，合成了一种有机硼交联剂YGB 1，通过交联时间的测定对交联比和调节剂用量进行优化；并对稠化剂、加重剂和其他添加剂进行了优选，形成了密度为1.35 g/cm³、延迟交联时间在3～17 min内可调、适用于160 ℃储层的加重胍胶压裂液配方。通过耐温耐剪切实验、悬砂实验、降阻实验和破乳实验对压裂液的各项性能进行了测定，结果表明，该加重胍胶压裂液各项性能优异，在160 ℃、170 s^-1下剪切2 h后黏度仍保持在150 mPa·s以上；当混砂比为25%时，使用20～40目的陶粒在90 ℃条件下测试悬砂实验，悬浮0.5 h后，陶粒无沉降；测试管路为6 mm，当排量为3.5 m³/h时，加重压裂液的降阻率为61%；破胶液表面张力为24.8 mN/m，残渣含量为398.2 mg/L；破胶液防膨率为91%。

A Study on a Kind of Delayed Crosslinking Anti-high Temperature Weighted Guanidine Gel Fracture Fluid

The problems of deep well reservoir, such as deep burial depth, tight lithology, high fracture pressure and fracture extension pressure, lead to high pressure and difficulty in fracturing, and low density of conventional fracturing fluid, which cannot guarantee the construction safety and effect of measures. In order to solve the above problems, a kind of organoboron crosslinking agent YGB-1 was synthesized in this paper, and the crosslinking ratio and the amount of regulator were optimized by the determination of crosslinking time. The thickening agent, weighting agent and other additives were optimized to form a fracturing fluid formula with density of 1.35 g/cm³, adjustable delay crosslinking time within 3～17 min, and suitable for 160℃ reservoir. Various properties of the fracturing fluid were measured through the temperature and shear resistance test, suspended sand test, resistance reduction test and demulsification test. The results showed that the enhanced guanidine gel fracturing fluid had excellent properties. The viscosity remained above 150 mPa·s after 2 h shear at 160℃ and 170 s^-1. At 90℃, when the sand ratio is 25%, the ceramsite (20～40 meshes) was suspended for 0.5 h without settlement. When the test line is 6 mm and displacement is 3.5 m³/h, the drag reduction rate of the weighted fracturing fluid is 61%. The surface tension of the broken glue solution was 24.8 mN/m, and the residue content was 398.2 mg/L. The anti-swelling rate of broken glue solution was 91%.