黏土稳定剂和稠油降黏剂对稠油乳状液破乳性能的影响

Influence of Clay Stabilizer and Viscosity Reducer on the Demulsification of Heavy Oil Emulsion

为研究三次采油过程中黏土稳定剂和稠油降黏剂对破乳的影响机理,采用界面膨胀流变仪考察了阳离子型黏土稳定剂NT-1A、阴离子和非离子复配型稠油降黏剂JN-1A对滨南原油及四组分破乳体系界面膜强度的影响,应用原子力显微镜观察了NT-1A、JN-1A对沥青质聚集结构和形貌的影响。结果表明:原油中沥青质有较高的扩张模量;NT-1A通过静电吸引作用促进沥青质分子交联聚集体的形成,使聚集体粒径由489 nm增至665nm,导致界面膜强度增强,原油界面扩张模量由3.23 m N/m增至5.93 m N/m,脱水率由77.27%降至7.80%;JN-1A在油水界面上的吸附能力较强,部分顶替原油中的活性组分,抑制沥青质分子在油水界面上的聚集,聚集体粒径由489 nm降至215 nm,导致界面膜强度降低,原油界面扩张模量由3.23 m N/m降至1.68 m N/m,脱水率由77.27%增至87.50%。NT-1A、JN-1A主要通过改变原油中的活性组分沥青质的交联强度,影响界面扩张模量,从而影响稠油乳状液的破乳效果。

In order to study the influence mechanism of clay stabilizer and heavy oil viscosity reducer on the demulsification in the process of tertiary oil recovery, the influence of cationic clay stabilizer NT-1A and anionic and non-ionic compounded viscosity reducer JN-1A on the interfacial film strength of Binnan crude oil and four components demulsification was studied by means of interface expansion rheometer. The effects of NT-1A and JN-1A on the structure and morphology of asphaltene aggregation were observed by AFM. The results showed that asphaltene in crude oil had a higher modulus expansion. NT-1A promoted the formation of cross-linked aggregates of asphaltene molecules by electrostatic attraction and the size of aggregates grew from 489 nm to 665 nm. As a result, the interfacial film strength enhanced, which made the dilational modulus of crude oil increase from 3.23 mN/m to 5.93 mN/m and the dehydration rate reduce from 77.27% to 7.80%. JN-1A had stronger ability on the oil-water interface adsorption and replaced the active ingredient in crude oil. It inhibited the aggregation of asphaltene molecules on oil-water interface and the size of aggregates dropped from 489 nm to 215 nm. As a result, the interfacial film strength decreased, which made the dilational modulus reduce from 3.23 mN/m to 1.68 mN/m and the dehydration rate increase from 77.27% to 87.50%. NT-1A and JN-1A had a significant impact on the demulsification of heavy oil crude by changing the dilational modulus of asphaltene.