响应面优化深层废弃水基钻井液无害化处理工艺

针对大庆油田深层致密气废弃水基钻井液固液分离难、泥饼含水率高（＞80%）、存在二次污染的问题，开展了废弃水基钻井液无害化处理技术研究，在分析废弃水基钻井液特性与处理难点基础上，应用Box-Behnken中心组合实验和响应面分析法，通过考察破胶剂、助凝剂与絮凝剂的最佳配比对废弃钻井液固液分离效果的影响，创新建立了固液分离泥饼含水率与处理配方参数间的数学模型，研发出了以脱稳絮凝为核心的废弃水基钻井液无害化处理技术，形成了脱稳-絮凝-固液分离处理工艺。现场实验结果表明，废弃水基钻井液经该项技术处理后，泥饼含水率为47%，泥饼浸出液悬浮物含量为63 mg/L，泥饼浸出液中石油类、COD等9项主要污染指标符合GB 8978—1998《污水综合排放标准》、DB23/T 693—2000《黑龙江省废弃钻井液处理规范》相关要求，该技术成果解决了大庆油田深层水基钻井液破胶脱稳效果差等难题，具有较好的推广应用价值。 

Response Surface Optimization of Biosafety Disposal of Waste Water Based Drilling Fluids for Deep Drilling

Water based drilling fluids have been used to drill deep tight gas wells in Daqing Oilfield. In the treatment of the waste drilling fluids, it was found that the solids and the liquids were difficult to be separated from each other, the mud cakes had water-cut of greater than 80%, and secondary contamination existed in future operations. A study on the bio-safety disposal of waste water based drilling fluids was conducted to solve these problems. Based on the analyses of the characteristics of and difficulties in the treatment of the water drilling fluids, the Box-Behnken Central Composite Experiment and Response Surface Method were chosen as a means of study. By exploring the effects of the optimum ratio of gel breaker, coagulant aid and flocculant on the solid-liquid separation efficiency of the waste water based drilling fluids, a new mathematical model was established describing the relationship between the water-cut of mud cakes for solids-liquid separation and the treatment recipe parameters. A method for the biosafety disposal of waste water based drilling fluids was developed, with destabilization and flocculation as the core technique. Using the mathematical model and the biosafety disposal method, a destabilization-flocculation-solid-liquid separation technique was established. Field test results have shown that a waste water based drilling fluid, after treatment with the technique, formed a mud cake with water-cut of 47%, the suspension content in the mud cake leachate was 63 mg/L. Nine major pollution indices such as COD etc. of the waste drilling fluid conform to the requirements of the national standard GB 8978—1998 and the local standard DB23/T 693—2000, namely, “Waste Drilling Fluid Treatment Specification of Heilongjiang Province”. This technology provides an effective solution to the poor gel breaking and destabilization efficiency of the water based drilling fluids for deep hole drilling in Daqing Oilfield and has good promotion and application values.