疏水缔合聚合物/表面活性剂压裂液的性能

Study on the Performance of Hydrophobic Associating Polymer/Surfactant Fracturing Fluid

摘要:

采用动态流变仪考察了疏水缔合聚合物HAP溶液的稳态流变性能，并考察了表面活性剂对HAP溶液的影响。结果表明：HAP溶液的表观黏度随着剪切速率的增加而下降随后基本不变。以HAP和十二烷基硫酸钠（SDS）配制了一种疏水缔合聚合物压裂液HAP-M，评价了其耐温耐剪切性、黏弹性、触变性、静态悬砂性能和破胶性能。HAP-M压裂液具有较好的耐温耐剪切性能，在90℃、170s-1的条件下连续剪切90min黏度仍能保持在50mPa?s以上。通过黏弹性测试，得出HAP-M压裂液的储能模量G'和损耗模量G''随应力基本不发生变化，G'大于G''，说明HAP-M压裂液具有黏弹性并且以弹性行为为主。HAP-M压裂液触变性优于羟丙基胍胶（HPG）压裂液。HAP-M压裂液静态悬砂性能较好，在砂比40%条件下，砂子的沉降速率为8.2?10-4mm/s。在80℃下加入过硫酸铵破胶剂，1h内即可破胶，破胶液黏度在5mPa?s以下，表面张力为25.14mN/m，与航空煤油的界面张力为0.56mN/m。

Abstract:

Steady rheological behavior of HAP aqueous solution was investigated by using dynamic rheometer. Effect of surfactant on HAP aqueous solution was also investigated. The results showed the apparent viscosity of HAP aqueous solution decreased and then kept constant with the increment of shear rate. A hydrophobic associating polymer fracturing fluid (HAP-M) were prepared by HAP and sodium dodecyl sulfate (SDS). Heat and shear resistance, viscoelasticity, thixotropy, proppant-carrying capacity and gel breaking property of HAP-M fracturing fluid were evaluated. HAP-M fracturing fluid has a good heat and shear resistance. Its viscosity can remain above 50 mPa•s after shearing at the rate of 170 s-1 for 90 min at the temperature of 90℃. According to the viscoelasticity results of HAP-M fracturing fluid, both of the storage modulus (G') and loss modulus (G″) do not change with the stress changing, and G' is larger than G″, which indicates that HAP-M fracturing fluid is of viscoelasticity and mainly elastic behavior. Furthermore, the thixotropy of HAP-M fracturing fluid is better than that of hydroxypropyl guar gum (HPG) fracturing fluid. The sedimentation rate is 1.18 mm/s on the condition of 40% sand ratio，which indicates that the fracturing fluid has a good proppant-carrying capacity. The gel breaker of ammonium persulfate can make the fracturing fluid gel break in 1 h at 80℃.The viscosity of gel breaking liquid is less than 5 mPa•s and the surface tension and interfacial tension of that are 25.14 mN/m and 0.56 mN/m, respectively.