高温老化对粘土降滤失剂体系滤失作用研究

考察了高温老化对降滤失剂SMPFL与钠蒙脱土Na-MMT复配体系的滤失性能及影响规律,通过体系黏度、红外光谱、SEM及Zeta电位等考察了体系的高温失稳机理。老化前SMPFL在Na-MMT表面的吸附造成颗粒Zeta电势、水化膜厚度以及颗粒间斥力增加,而且使颗粒在泥饼中松散堆积增大了泥饼渗透率,滤失量的降低主要原因是体系黏度的增高;虽然高温造成Na-MMT/SMPFL体系滤失量增大,但老化后SMPFL仍具有良好的控滤失性能。高温老化造成Na-MMT与SMPFL间氢键作用力减弱,加速聚合物从颗粒表面的脱附、减小颗粒水化膜厚度,而且导致SMPFL的水解。与老化前相比,老化后体系滤失量的降低主要原因是泥饼渗透率的降低。

Effect of high-temperature aging on the filtration of clay/filtrate reducer dispersion

The filtration properties of filtrate reducer SMPFL and sodium montmorillonite (Na-MMT) base mud before and after high temperature aging were evaluated. The high temperature destabilization mechanisms were deduced by viscosity, IR spectrum, SEM and zeta potential measurements. For the non-aged base mud, the adsorption of SMPFL at Na-MMT surface is contributed to the increase of zeta potential and the thickness of hydration film. The enhancement of repulsive force between Na-MMT particles causes the loose accumulation of Na-MMT particles in mud cake and the improvement of filter cake permeability. In this case the decrease of fluid loss is mainly attributed to the improvement of filtrate viscosity. The high temperature aging has significant influences on the filtration of Na-MMT/SMPFL base mud, whereas the filtrate reducer still has an excellent filtrate controlling capacity. The high temperature aging not only weakens the hydrogen bonding between SMPFL and Na-MMT, accelerates the desorption from particle surface, decreases the hydration film thickness of solid particles, but causes the hydrolysis of filtrate reducer. Compared with non-aged dispersion, the decrease of filtration for the aged dispersion is mainly attributed to the reduction of permeability.