【摘要】 针对超临界CO₂压裂液黏度低、携砂性能差等缺点,进行了CO₂压裂液的增黏剂ZNJ分子设计和助溶剂优选及性能测试,对优选后的CO₂压裂液体系的流变性、携砂性、摩阻进行了测试。结果表明:在-10～60℃,10～20 MPa条件下,加1.0%～2.0%增黏剂的CO₂压裂液黏度是纯CO₂压裂液的5～61倍;增黏剂质量分数对CO₂压裂液黏度影响最大,其次是温度和压力;支撑剂在加有2.0%增黏剂的CO₂压裂液中的沉降速度比在纯CO₂压裂液中慢14.5%～37.4%,加增黏剂的CO₂压裂液携砂性能较好;在40℃,20 MPa条件下,ZNJ可有效降低超临界CO₂压裂液的摩阻;随着压裂液流速的增加,管柱摩阻急剧增加,故压裂时应选择合适的排量以降低摩阻。更多还原

【Abstract】 Aiming at the disadvantages of low viscosity and poor sand carrying capacity of supercritical CO₂ fracturing fluids, the supercritical CO₂ fluid tackifier ZNJ molecular design and cosolvent were optimized, and the performance testing was carried out.The rheological property, sand carrying capacity and friction resistance of the optimized CO₂ fracturing fluid system were tested. The results show that the viscosity of CO₂ fracturing fluid added with 1.0%-2.0% tackifier system is 5-61 times higher than pure CO₂ fracturing fluid at-10-60 °C and 10-20 MPa; the viscosity of CO₂ fracturing fluid is affected most by the mass fraction of the tackifier, followed by temperature and pressure; the proppant settling rate in the CO₂ fracturing fluid with 2.0% tackifier system is14.5%-37.4% slower than that in the pure CO₂ fracturing fluid, and the CO₂ fracturing fluid with tackifier has better sand carrying capacity; at 40 °C and 20 MPa, ZNJ can effectively reduce the frictional resistance of the supercritical CO₂ fracturing fluid; with the increase of fracturing fluid flow rate, the friction resistance of pipe string increases sharply, so the optimal displacement should be selected to reduce the friction resistance when fracturing.更多还原