改性多元醇防塌剂的研制及其作用机理研究

Development of modified polyalcohol anti-sloughing agent and its anti-sloughing mechanisms

通过降解和阳离子化反应,研制出了抑制性好而增粘负效应较低的改性多元醇防塌剂SD-306;通过红外光谱分析了改性多元醇防塌剂的分子结构,证明阳离子化反应引入了正氮基团;通过滚动分散、电动电位测量、粒度分布测量、吸附以及压力传递等实验手段,探讨了改性多元醇防塌剂的作用机理。结果表明,改性多元醇的防塌机理主要为:通过吸附包被防止泥页岩颗粒水化分散;多元醇吸附在泥页岩颗粒表面,改变其表面电荷,压缩扩散双电层,抑制泥页岩颗粒水化;吸附于地层岩石表面成膜,覆盖裂缝和孔隙表面,从而阻缓压力和钻井液滤液传递。

A novel polyalcohol anti-sloughing agent SD-306 with good anti sloughing function and lower side effect of increasing viscosity was developed through modifying polyvinyl alcohol （PVA）, It was proved that the modified PVA has ortho-nitrogen radicals by molecular structure analysis through infrared spectrum, The anti-sloughing mechanisms of modified polyalcohol were studied deeply through experiments including rolling and dispersing recovery, zeta potential and particle size distribution measuring, adsorption and pressure transmission. The following are the anti-sloughing mechanisms： The mud shale particles are prevented to hydrate and disperse by adsorbing and coating. The and shale particles hydration is checked through altering their surface charge and compressing their diffused double layer with polyalcohol adsorbing. The pressure and filtrate transfer are blocked through forming film and covering on the surface of slits and pores after adsorbing on the surface of rock in the stratum.