疏水两性黄原胶的制备及流变性能评价

Preparation and Rheology Evaluation of Hydrophobic Amphoteric Xanthan Gum

为提高黄原胶的基本性能并拓宽其在石油开采领域的应用,采用环氧氯丙烷和十六叔胺合成了疏水阳离子醚化试剂(3-氯-2-羟丙基二甲基十六烷基醋酸铵),以此醚化试剂对黄原胶(XG)改性制备了疏水两性黄原胶(HAXG),研究了HAXG溶液的流变性能(表观黏度、触变性、流动曲线、黏弹性能)以及携砂性能、减阻性能、耐温耐剪切性能。结果表明,改性后HAXG溶液的表观黏度显著增强,0.4%HAXG溶液黏度(172.38 m Pa·s)是0.4%XG溶液黏度(42.54 m Pa·s)的4.05倍。XG和HAXG溶液具有假塑性流体的剪切变稀特性,其流动曲线均可用Cross模型进行描述。相较于XG,HAXG溶液具有更好的触变性能、黏弹性能和网络结构,从而表现出更加优良的携砂性能和耐温耐剪切性能。HAXG溶液的减阻性能好于XG,0.12%XG和HAXG溶液在光滑管中的最大减阻率分别为57.80%和65.01%。HAXG可作为减阻剂用于滑溜水压裂液。

In order to improve the basic performance of xanthan gum and widen its application, hydrophobic cationic etherifying agent （3-chloro-2-hydroxypropylhexadecyldimethylammonium acetate） was prepared by epichlorohydrin and hexadecyldimethylamine, and then a novel hydrophobic amphoteric xanthan gum was synthesized by xanthan gum （XG） and the etherifying agent. The rheological properties, proppant carrying capacity, drag reduction and heat and shear resistance of HAXG solution were studied in detail. The rheological results showed that the apparent viscosity of HAXG solution was significantly enhanced. The apparent viscosity of 0.4% HAXG solution （172.38 mPa. s） was 4.05 times as big as that of 0.4% XG solution （42.54 mPa · s）. Both XG and HAXG solutions behaved as pseudoplastic shear-thinning fluids, and the shear thinning behavior could be fitted quite well with Cross model. Compared with XG solution, HAXG solution exhibited more obvious thixotropy, much stronger viscoelasticity and network structure, thus better proppant carrying capacity and better heat and shear resistance. Both the two solution exhibited good drag reduction performance. With the concentration of 0.12%, the largest drag reduction rate of XG and HAXG solution was 57.80% and 65.01% respectively, indicating HAXG solution exhibited better drag reduction than XG solution. HAXG could be used as a drag reducing agent for slickwater fracturing fluid.