低品位膨润土提质改性制备钻井泥浆助剂研究

河南信阳上天梯地区蕴藏大量低品位钙基膨润土，该膨润土Φ600为2 mPa·s，滤失量为89 mL，无法满足钻井用膨润土的技术要求（GB/T 5005—2010，Φ600≥30 mPa·s，滤失量≤16 mL）。采用半干法改性工艺通过置换层间可交换阳离子制备钠基膨润土，当Na₂CO₃用量2.5%、钠化1.5 h时，滤失量降至31 mL。然后，通过单因素试验考察增效剂对钠基膨润土泥浆性能的影响，并结合X射线衍射、红外光谱和扫描电镜等测试手段考察各种增效剂的作用机理，最后通过正交试验优选和调控增效剂。结果显示，增效剂通过絮凝、桥联和交错吸附等方式形成立体网络结构，改善膨润土的泥浆性能。当添加质量分数1%的MgO和1%的APAM组成的复合增效剂时，膨润土Φ600为34 mPa·s，滤失量为12 mL，达到钻井级膨润土的技术要求。 

Study on Preparation of Drilling Mud Auxiliary by Upgrading and Modifying Low-grade Bentonite

There are a lot of low-grade calcium bentonite in Shangtianti area of Xinyang, Henan Province. The Φ600 of mud was 2 mPa·s and the filter loss was 89 mL, which can not meet the technical requirements of drilling grade bentonite(GB/T 5005-2010, Φ600 ≥ 30 mPa·s, filter loss ≤ 16 mL). Sodium modified bentonite was prepared by semi-dry modification process, when the dosage of sodium carbonate was 2.5% and sodium time for 1.5 hours, the mud filter loss decreased to 31 mL. Then, the influence of synergist on the properties of bentonite slurry was studied by single factor experiment. XRD, FTIR and SEM potential were used to investigate the mechanism of the effect of the synergist on the slurry-making properties of Bentonite. Finally, the synergist was optimized and regulated through orthogonal experiment. The results showed that the synergist facilitated the formation of network structures. when the composite synergist composed of 1% MgO and 1% APAM, the viscosity reached 34 mPa·s and the filter loss could be reduced to 12 mL, which could meet the technical requirements of bentonite for drilling.