一种亚微米固相絮凝剂的合成及性能评价  

Synthesis and Evaluation of a Submicron Solid Flocculant GCS

作　　者：蒋官澄[1] 李新亮[1] 彭双磊 赵利[2] 李公让 张敬辉 JIANG Guancheng;LI Xinliang;PENG Shuanglei;ZHAO Li;LI Gongrang;ZHANG Jinghui(School of Petroleum Engineering, China University of Petroleum, Beijing 102249;Kelamayi Drilling Company of CNPC Xibu Drilling Engineering Company Ltd., Kelamayi, Xinjiang 834000;Shengli Drilling Technology Research Institute of Sinopec, Dongying, Shandong 257017)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]西部钻探工程有限公司克拉玛依钻井公司,克拉玛依834000 [3]胜利石油工程有限公司钻井工艺研究院,山东东营257017

出　　处：《钻井液与完井液》2017年第4期15-19,共5页Drilling Fluid & Completion Fluid

基　　金：国家"十三五"重大专项"致密油气开发环境保护技术集成及关键装备"(2016ZX05040-005);中石油集团公司"十三五"项目"钻完井工厂化作业技术集成与应用"(2016D-4503);国家863计划主题项目"致密气藏高效钻井技术研究"(2013AA064803);国家自然科学基金面上和重点支持项目(51474231;U1262201)

摘　　要：钻井过程中钻井液中亚微米无用固相的含量会越来越高,对钻井液的性能影响很大,因此有必要研发有针对性的絮凝剂以清除钻井液中的亚微米固相。通过室内研究,合成了一种基于壳聚糖的亚微米固相絮凝剂GCS。通过正交实验对合成条件进行了优化,得到最佳壳聚糖浓度为3%,壳聚糖与交联剂质量比为1:0.28,pH值为7。通过粒度分析、沉降实验,对GCS的絮凝效果进行了评价,并采用红外光谱、Zeta电位、扫描电镜等方法分析了其絮凝机理。实验结果表明,GCS絮凝效果显著,对亚微米高岭土的絮凝率在95%以上,与聚丙烯酰胺类絮凝剂相比,不增黏,絮体粒径集中且易分离;在碱性条件下,GCS具有更好的絮凝效果,随着pH值和GCS加量增大,絮凝效果增强,絮体更加稳固;GCS可通过—OH、—NH以及—C=N、—NH_2等官能团与高岭土颗粒发生强吸附作用,并与颗粒表面发生电中和作用,使高岭土颗粒电位升高、聚结沉降,达到高效絮凝作用。Submicron solids laden in drilling fluid as drilling proceeds greatly affect the properties of the drilling fluid,and are thus needed to be removed with flocculants dedicated for the submicron solids.GCS is such a flocculant synthesized with chitosan.The optimum synthetic conditions determined through orthogonal experiment were as follows:3%chitosan,mass ratio of chitosan and crosslinking agent=1∶0.28,pH=7.Particle size analysis and sedimentation test were done to evaluate the flocculating effect of GCS,and the flocculating mechanisms of GCS were determined through IR spectroscopy,zeta potential measurement and SEM.It has been found that GCS has good flocculating ability,95%of submicron kaolinite particles can be flocculated.Compared with other flocculants,such as polyacrylamide,GCS does not viscosify drilling fluids;the sizes of the flocs are narrowly distributed and are thus easy to be separated from drilling fluid.GCS has better flocculating effect in alkaline environment.At higher pH value and GCS concentrations,better flocculation can be achieved,and the flocs become more compact.GCS has-OH,-NH,-C═N and-NH2functional groups with which GCS is tightly adsorbed onto the surface of kaolinite particles through these groups,neutralizing the electric charges on the surface of the kaolinite surface,hence increasing the potential of kaolinite particles,thereby coalescing the particles to form flocs.

关 键 词：絮凝剂 亚微米 固相 水基钻井液 

分 类 号：TE254.4[石油与天然气工程—油气井工程]