纳米SiO2防气窜乳液制备及分散稳定性研究  

Preparation and dispersion stability of nano-SiO2 anti-migration emulsion

作　　者：杨红歧[1] 魏浩光[1] YANG Hongqi;WEI Haoguang(SINOPEC Research Institute of Petroleum Engineering,Beijing 100101,China)

机构地区：[1]中国石油化工股份有限公司石油工程技术研究院,北京100101

出　　处：《石油化工应用》2020年第5期109-113,共5页Petrochemical Industry Application

基　　金：“十三五”国家科技重大专项“高压低渗气井水平井固井技术研究”部分研究内容,项目编号:2016ZX05021-005。

摘　　要：针对高温高压超深油气井防气窜固井技术难题,以纳米SiO2作为原材料制备的防气窜乳液具有良好的抗温性和防气窜效果,但超细纳米材料颗粒表面存在非常多的硅羟基,极易团聚在一起,乳液里的固相材料会沉淀、结块,造成产品失效。本文以搅拌分散为实验手段,研制了纳米SiO2防气窜乳液,通过Zeta电位、表观黏度、粒径分析、稳定性分析等表征方法,研究了影响乳液分散稳定性的化学因素。结果表明:纳米SiO2乳液的pH值应在11~12,颗粒间的静电斥力强,乳液的平均粒径小、表观黏度低,分散效果好;电解质存在压缩双电层效应,可大幅度降低纳米颗粒间的静电斥力,制备纳米SiO2防窜乳液应避免引入电解质;电位阻型分散剂SCNF加量达到5%时就接近饱和吸附量,当分散剂加量过大后,只能对外相水产生增黏作用;加入稳定剂增加了纳米SiO2颗粒的布朗运动阻力,可以大幅度提高纳米SiO2防窜乳液的稳定性,所制得的乳液平均粒径小于200 nm,固含量可达45%,室温下可储存一年以上,底部无析水沉淀现象。Anti-migration in view of the high temperature and high pressure deep oil and gas well cementing technology problem,anti-migration with nano SiO2 as raw material preparation of emulsion has good resistance to temperature and anti-migration prevention effect.But the ultrafine nanomaterials particles exist a lot of surface,easy to reunite together,the solid phase in the emulsion material will precipitate,agglomerate,cause product failure.This paper researches on the chemical technology of producing nano-SiO2 anti-migration emulsion by the experimental method of dispersers and the measurements such as rheological property,particle size analysis,stability analysis and so on.The result indicates that during pH value between 11 and 12 the nano-SiO2 emulsion has the strong electrostatic repulsion between the particles,and the average particle size of the emulsion is small,then the apparent viscosity is low.The production of nano-SiO2 anti-migration emulsion should avoid introducing electrolyte which compresses their diffused double layer and largely decreases the electrostatic repulsion between nano-particles.It will be closed to saturation adsorption when the dosage of the potential steric hindrance dispersant SCNF reaches 5 percent.If the dosage of dispersant is too much,it will increase the viscosity of external water.Adding the stabilizer can increase the Brownian motion resistance of nano-SiO2 particles,which can greatly improve the stability of the nanometer anti-migration emulsion.The produced emulsion has the feature that its average diameter is less than 200 nm,and solid content can reach 45 percent.It can store more than one year at room temperature without water separating and sedimentation at bottom.

关 键 词：纳米SIO2 乳液 分散 稳定性 黏度 静电斥力 

分 类 号：TE256.7[石油与天然气工程—油气井工程]