丁基羟基茴香醚提高冲洗液抗高温性的研究

针对油基钻井液难清洗，易与水泥浆产生絮凝，影响固井质量的问题，制备了以糠醛作为清洗助剂的水基冲洗液TGD-65。为使TGD-65适用于高温条件下的固井作业，引入了BHA （丁基羟基茴香醚）作糠醛高温稳定剂，并制备了TGD-60。实验结果表明，BHA可明显提高糠醛在高温条件下的稳定性，使TGD-60在160℃下对油基钻井液仍具有很好的乳化分散作用，可完全破坏油基钻井液的结构，使其分散成细小的液滴，从而转变为水包油状态。同时，高温处理后的冲洗液TGD-60对油基泥饼具有良好的润湿性，其在高温条件下的冲洗效率也由TGD-65的79.71%提升至99.18%。 

Use Butylated Hydroxyanisole to Improve High Temperature Stability of Flushing Fluid

Oil base drilling fluids (OBMs) are widely used because of their high temperature stability, resistance to salt and calcium contamination, good lubricity and low filtration rate, the problems of using OBMs are difficulty in cleaning them off the borehole wall and casing string and being ready to flocculate, thus negatively affecting the quality of well cementing. To effectively flush residue OBMs off the borehole wall and the surface of casing strings, a water base flushing fluid, TGD-65, was formulated, with furfuraldehyde as flushing additive. BHA, a high temperature stabilizer for furfur-aldehyde was used for the flushing fluid (called TGD-60) to work at elevated temperatures. Experimental results showed that BHA had the ability to enhance the high temperature stability of furfur-aldehyde, rendering TGD-60 good emulsification dispersion to OBM at 160℃, completely breaking the structure of OBM to small-sized droplets. The OBM was finally turned into oil-in-water emulsion. Meanwhile the flushing fluid after high temperature treatment had good wettability to the mud cakes formed by OBM, and the flushing efficiency at high temperatures was enhanced from 79.71% to 99.18%.