纳米材料对低固相冲洗液性能影响的研究

Influence of nanomaterials on the properties of low-solid drilling fluids

摘要:

低固相冲洗液是最适合绳索取心钻探工艺的冲洗液类型之一，但其防塌护壁能力和钻孔净化能力弱，阻碍了绳索取心钻探工艺在复杂地层的应用。本文通过实验研究，分析了纳米四氧化三铁、纳米氮化硼、纳米二氧化钛、多壁碳纳米管和纳米二氧化硅对低固相冲洗液的流变性能和滤失性能的影响规律。结果表明：纳米四氧化三铁、多壁碳纳米管和纳米氮化硼对低固相冲洗液的性能影响最明显，且具有增粘提切的作用。在此基础之上，通过正交实验分析了上述3种纳米材料复合后对低固相冲洗液性能的影响规律，得到性能优良的复合纳米低固相冲洗液体系优化配方：3%钠基膨润土+0.5%CMC-HV+0.3%纳米四氧化三铁+0.9%纳米氮化硼+0.9%多壁碳纳米管。最后，分析了纳米材料改善低固相冲洗液性能的作用机理。

关键词:纳米材料;低固相冲洗液;流变性能;滤失性能;绳索取心钻探

Abstract:

The low-solid drilling fluid is one of the most suitable drilling fluids for wireline core drilling； however， its poor anti-collapse and borehole cleaning capabilities hinder the application of wireline coring drilling in complex formations. The effects of nano-iron tetroxide， nano-boron nitride， nano-titanium dioxide， multi-wall carbon nanotubes and nano-silica on the rheological properties and filtration properties of low-solid drilling fluids were analyzed through experimental research. The results showed that： nano-iron tetroxide， multi-walled carbon nanotubes and nano-boron nitride had obvious effects on the performance of low-solid drilling fluids； furthermore， they can increase the viscosity and improve shear force. Then， the influence of the combination of the above three nanomaterials on the performance of the low-solid drilling fluid was analyzed by orthogonal experiments to obtain the optimized formulation of the composite nano-low-solid drilling fluid system with excellent performance： 3% sodium bentonite + 0.5% CMC-HV + 0.3% nano ferric oxide + 0.9% nanoboron nitride + 0.9% multi-walled carbon nanotubes. Finally， the mechanism of nanomaterials to improve the performance of low-solid drilling fluids is analyzed.

Key words:nanomaterials;low-solid drilling fluid;rheological properties;filtration properties;wireline core drilling