渗吸采油用非交联缔合型清洁压裂液体系

Non-crosslinked Associative Clean Fracturing Fluid System for Imbibition Oil Recovery

任洪达 许成军 孙锡泽 蒲迪 董景锋 郭拥军

REN Hongda XU Chengjun SUN Xize PU Di DONG Jingfeng GUO Yongjun

为进一步提高渗吸采油压裂液焖井后的采收率，研究了破胶液中不同残渣含量及稠化剂相对分子质量对渗吸采收率的影响，通过渗吸剂优选及其对非交联缔合型稠化剂（CFZ）增黏、耐温耐剪切、渗吸采收率性能的影响研究，构建优化了一套残渣低、相对分子质量低的渗吸采油非交联缔合型清洁压裂液体系。研究表明：破胶液中残渣含量及相对分子质量越低，对渗吸采收率影响越小。配方为0.3% 稠化剂CFZ+0.2% 渗吸剂SZX-1+0.06% 破胶剂APS 的渗吸采油非交联缔合型清洁压裂液体系，在90 ℃、170 s-1下剪切90 min 的黏度为77.43mPa·s，破胶液在油湿岩心表面接触角为31.6°，油水界面张力为0.66 mN/m，残渣含量为17.2 mg/L，相对分子质量为1.15×104，渗吸采收率为14.8%。该体系可为进一步提高压裂后的渗吸采收率提供理论依据及技术支持。

In order to further improve the recovery of imbibition fracturing fluid after well shut-in，the effects of different residue content and molecular weight of the thickener in fracturing fluid gel breaker on imbibition recovery were studied. Through the optimization of imbibition agent and its effects on the viscosity increasing，temperature resistance，shear resistance and imbibition recovery performance of non-crosslinked associative thickener（CFZ），a set of imbibition recovery non-crosslinked associative clean fracturing fluid system with low residue and low molecular weight was constructed and optimized. The results showed that the lower the residue content and molecular weight in gel breaker，the smaller the effect on imbibition recovery. When the system， composed of 0.3% thickener CFZ + 0.2% imbibition agent SZX-1 + 0.06% gel breaker APS，was sheared at the temperature of 90 ℃ and at the shear rate of 170 s-1 for 90 min，the viscosity was 77.43 mPa·s. The contact angle of the gel breaker on oil wet surface was 31.6°，the oil-water interfacial tension was 0.66 mN/m，the residue content was 17.2 mg/L and the molecular weight of the thicker in the gel breaker was 1.15 × 104 ，the imbibition recovery was 14.8%. The system provided the theoretical basis and technical support for further improving the imbibition recovery after fracturing.

10.19346/j.cnki.1000-4092.2022.02.010