水基压裂用聚电解质复合溶液的研究

Study on Composite Polyelectrolyte Solution Used in Water Base Fracturing Fluid

以物理交联为出发点,以聚电解质复合为基础,探讨聚电解质复合溶液作为压裂液稠化剂的可行性。实验发现调节阴、阳聚电解质的分子量和阳离子度等条件得到均相稳定的聚电解质复合物。分子量为80万和阳离子度为9.1%的阳离子聚合物与分子量为2 200万的阴离子聚合物复合形成具有高黏弹性能的聚电解质复合物。聚电解质复合物溶液的电子扫描显微镜(SEM)表明,通过库伦力的作用而形成的聚电解质复合物形成网络结构,且不同状态的聚电解质复合物的网络结构不同。对可以作为压裂液增稠剂的聚电解质复合物溶液的流变分析表明,其具有良好的黏弹性能,在频率大于0.1 Hz时,储能模量远大于耗能模量。黏温曲线显示在170 s-1剪切速率下、130℃时,该聚电解质复合物溶液的黏度仍保持在40 m Pa·s以上。实验现象表明均相聚电解质复合物有望形成一种新的超分子压裂液体系。

Composite polyelectrolyte solution is studied for its use in fracturing fluid as thickening agent.It was found that stable homogeneous composite polyelectrolyte can be obtained by adjusting the molecular weights of anionic and cationic polyelectrolytes,and the cationic degreeof cationic polyelectrolytes.A cationic polymer with molecular weight of 800,000 and cationic degree of 9.1%,when mixed with an anionic polymer with molecular weight of 22,000,000,produces a composite polyelectrolyte with high viscoelasticity,Study of the composite polyelectrolyte with SEM shows that network structures are generated in polyelectrolyte formed through Coulomb force,and the network structures vary with different polyelectrolyte morphology.Analyses of the rheology of the solution of a composite polyclectrolyte used in fracturing fluids show that it has excellent viscoelasticity,and the storage modulus is far greater than the loss modulus at a frequency of 0.1 Hz.Viscosity- temperature curves show that at shear rate of 170 s^(-1) and 130℃,the composite polyelectrolyte solution still retain viscosity that is greater than 40 mPa·s.Homogeneous composite polyelectrolyte is expected to be used to prepare a new fracturing fluid system,