非交联缔合结构压裂液新型增黏辅剂优选与性能评价

Selection and Evaluation of Novel Tackifying Adjuvant in Non-Crosslinked Associative Structural Fracturing Fluid

研究了以疏水缔合聚合物GRF-1H为稠化剂的非交联缔合结构压裂液基液与疏水尾基碳原子个数分别为6、10、14的新型非离子表面活性剂(GS-1、GS-2、GS-3)复配后体系表观黏度的变化规律,优选出了适用于该压裂液的增黏辅剂GS-3;确定了该辅剂的最佳浓度及适用温度范围;评价了其对压裂液基液黏性及黏弹性的影响。实验结果表明,加入微量(0.03%率0.05%)GS-3即可大幅提升基液表观黏度,其最佳浓度为体系峰值表观黏度对应的浓度,适用温度范围为30率90℃;在测试浓度范围内,随GS-3浓度增加,体系表观黏度先增大后减小,变化趋势符合Biggs三阶段模型;温度从30℃增至120℃时,体系表观黏度先增大后减小,63℃下的增黏率最大(168%);GS-3还可大幅提升基液黏弹性,储能模量可提升1率10倍;使用GS-3作为增黏辅剂,可达到降低压裂液稠化剂用量的目的。

Viscosity change regularity of adding novel non-ionic surfactants(GS-1,GS-2 and GS-3)with different hydrophobic chain length to non-crosslinked associative structural fracturing fluid using hydrophobic associative polymer as thickener was investigated. The number of carbon atoms in hydrophobic tail of GS-1,GS-2 and GS-3 was 6,10 and 14,respectively. GS-3 was selected as the optimal tackifying adjuvant for the fracturing fluid accordingly. The optimum concentration and application temperature range of GS-3 were obtained. And the influence of GS-3 on the viscosity and viscoelasticity of base fracturing fluid was also investigated. The results of experiments showed that the apparent viscosity of fracturing fluid could be greatly increased by adding traces GS-3(0.03% —0.05%). The optimum concentration of GS-3 was the concentration corresponding to the peak apparent viscosity of complex system and its applicable temperature range was 30—90℃. Within the test concentration range,the apparent viscosity of system increased first and then decreased,the change trend accorded with Biggs' s 3 periods model. When the temperature increased from 30℃ to 120℃,the apparent viscosity of system also increased first and then decreased. The maximum tackifying rate was 168% at 63℃. The viscoelasticity of fracturing fluid was also enhanced simultaneously. The storage modulus could be increased 1—10 times according to the concentration of thickener. So the dosage of thickener could be greatly decreased by using GS-3 as tackifying adjuvant.