高浓度高分子量部分水解聚丙烯酰胺与低黏纤维素共混堵漏体系性能评价

Performance Evaluation of Low Viscosity Cellulose and Partially Hydrolyzed Polyacrylamide with High Concentration and High Molecular Weight Blend System

姚普勇

YAO Puyong

为获得高浓度高分子量聚合物与低黏纤维素共混堵漏体系的性能特征，采用应力控制流变仪、黏度计、扫描电子显微镜和冻胶阀承压测试装置等研究了高浓度、高分子量部分水解聚丙烯酰胺（HPAM）与低黏纤维素、醋酸铬交联剂、pH调节剂（NaHCO3）共混堵漏体系的黏弹性和固化后的承压强度。结果表明，HPAM溶液的储能模量随相对分子质量的增加而增大；添加低黏纤维素与交联剂可大幅提高HPAM溶液的黏弹性，体系黏度和固化后承压强度均随低黏纤维素加量的增加而增大；NaHCO3可延缓体系交联的速度，随NaHCO3加量增大，体系黏度和承压强度略有降低。25 g/L HPAM+1500 mg/L 低黏纤维素+100 mg/L 醋酸铬交联剂+20 mg/L NaHCO3体系的泵注性能良好，泵注时间90 min内的黏度控制在2 Pa·s 以内；该体系耐盐性良好，在70℃油藏温度条件下固化后的承压强度为0.5 MPa/m，满足堵漏作业封堵性能要求。在L-357 井堵漏施工中，挤注压力最高达11.9MPa，挤入量6 m3，施工完成后对漏失层段试压15 MPa，30 min内压力保持不变。图6 表5 参22

In order to obtain the performance characteristic of low viscosity cellulose and polymer with high concentration and high molecular weight blend system，the viscoelasticity and bearing strength after curing of plugging system which was composed of partially hydrolyzed polyacrylamide（HPAM），cellulose，chromium acetate cross-linking agent and pH regulator（NaHCO3）were investigated by using stress controlled rheometer，viscometer，scanning electron microscope and self-made gel slug pressure testing device. The results showed that the storage modulus of HPAM aqueous solution increased with increasing molecular weight. The viscoelasticity of HPAM aqueous solution could be improved significantly by the addition of crosslinking agent and cellulose with low viscosity. Both the viscosity and bearing strength of this system increased with increasing concentration of cellulose，while that decreased with increasing concentration of NaHCO3 because the cross-linked rate was delayed by NaHCO3. The system which was composed of 25 g/L HPAM，1500 mg/L low viscosity cellulose，100 mg/L chromium acetate crosslinker and 20 mg/L NaHCO3 had good pumping performance and salt tolerance，and its viscosity was lower than 2 Pa·s when the pumping time was 90 min. The bearing strength of the curing system was 0.5 MPa/m at reservoir temperature（70℃），which met the requirements of plugging in sealing operation. In the L-357 well plugging construction，the injection pressure was up to 11.9 MPa，and the extrusion capacity was 6 m3. After the completion of the construction，the pressure loss test of the leakage section was 15 MPa，and the pressure in 30 min remained the same.

10.19346./j.cnki.1000-4092.2017.03.007