新型非磺化环保低摩阻钻井液

深井、超深井钻探普遍采用耐温性较好的聚磺钻井液，其中磺化褐煤等磺化材料具有生物毒性、可降解性差，导致聚磺钻井液处理难度大、成本高。推荐了一套适用性强的钻井液环保性能评价标准，测试了聚磺钻井液及其主要处理剂的环保性能。以抗高温环保降滤失剂、流型调节剂代替传统磺化材料；以树枝状聚合物封堵抑制剂、纳微米封堵剂等代替磺化沥青、乳化沥青；以环保润滑剂替代原油，研发了一种新型非磺化环保低摩阻钻井液，并在塔河TK4120井进行了试验应用。结果表明，现场聚磺钻井液样本呈现中等毒性、较难生物降解、部分重金属含量超标，主要是磺化材料及原油生物降解性差和具有毒性所导致。非磺化环保低摩阻钻井液具有较强的抑制、封堵防塌及润滑性能，无毒，易生物降解。现场应用表明，该体系性能稳定，具有较强的抗温性，防塌能力强，润滑性能好，易塌地层平均井径扩大率仅为4.39%，4209 m长裸眼电测、下套管一次成功，取得了较好的应用效果。 

The Development and Application of a New Environmentally Friendly Low Friction Non-Sulfonate Drilling Fluid

Polymer-sulfonate drilling fluids, which have good resistance to high temperatures, are generally used to drill deep and ultra-deep wells. Chemicals used in these drilling fluids, such as sulfonated lignite and sulfonated methyl phenolic resin, have biotoxicity and poor degradability, resulting in difficulties in the disposal of the polymer sulfonate drilling fluids and high cost. In a laboratory study an applicable evaluation practice for testing the environmental friendliness of drilling fluids was recommended for testing the effects of polymer sulfonate drilling fluids and the main additives on the protection of environment. A new non-sulfonate drilling fluid with a balance between the functionality of the drilling fluid and environment protection was developed. This drilling fluid, with low friction coefficient, was successfully used in drilling the well TK4120 in Tahe block. Polymer sulfonate drilling fluids used in this block have moderate toxicity, poor degradability, and the contents of some heavy metals exceed the national standards. These problems come from the poor biodegradability and toxicity of the sulfonates and the crude oil used. Compared with the polymer sulfonate drilling fluids, the non-sulfonate drilling fluid developed has strong inhibitive capacity, plugging capacity and the ability to prevent the borehole wall from collapsing. It is nontoxic, easy to biologically degrade and environmentally friendly. Field application of this non-sulfonate drilling fluid indicated that this drilling fluid had stable property, good high-temperature resistance, strong ability to prevent borehole wall from collapsing, and good lubricity. The average rate of hole enlargement in the easy-to-collapse formations was only 4.39%. Wireline logging and running casing into a long open hole of 4,209 m were done successfully in the first try.