吉木萨尔页岩油乳化原因分析

Analysis of Emulsification Causes of Jimusar Shale Oil

罗腾 郭拥军 郑苗 蒲迪 邬国栋 李霞 胡俊 金诚

LUO Teng GUO Yongjun ZHENG Miao PU Di WU Guodong LI Xia HU Jun JIN Cheng

为了探究吉木萨尔页岩油乳化严重的原因，首先将吉木萨尔油田稠油分离成胶质、沥青质、剩余分3 个组分，然后使用元素分析仪测定原油及其胶质的元素组成，采用高分辨傅立叶变换离子回旋共振质谱仪（FT-ICR MS）分别对原油及其胶质中化合物的分子组成进行鉴定。研究结果表明，吉木萨尔页岩油的胶质含量为 43.19%，沥青质含量为0.31%，剩余分含量为56.5%，其中，胶质中的N含量是原油的2.3 倍左右，胶质中O和S含量是原油的1.82 和1.29 倍，说明吉木萨尔原油的主要乳化活性成分来自胶质。在负离子（-ESI）模式下，原油和胶质中非碱性极性化合物的相对分子质量分布范围均为200～600 Da，质量中心在m/z=350 处；主要检测到了咔唑类（N1）、咔唑类氧化产物N1O1和N1O2及石油酸（O2）和酚类（O1）化合物，各组分含量大小顺序为：N1>N1O1>N1O2>O2>O1。由于N1类化合物含量较高导致了原油的乳化和缚水能力增加；此外N1的氧化产物N1O1和N1O2增加了原油的亲水性、极性和乳化性。O2和O1的存在进一步增强了原油的乳化能力。在正离子（+ESI）模式下，吉木萨尔原油及其胶质的碱性化合物相对分子质量范围在150～640 Da之间，原油的质量中心在m/z=350 处；胶质组分的质量中心在m/z=340 处；主要检测到N1和N2两种含氮化合物。其中N1类化合物占绝对优势，结构可能为八氢吖啶类、八氢菲啶类、喹啉类或异喹啉类化合物。该类物质在高温下微溶于水或亲水性增加，将导致原油在 高温下乳化性增强。因此，导致吉木萨尔页岩油乳化严重的主要表面活性物质为原油胶质中的含氮极性组分及其氧化物，此类化合物具有较高的界面活性，易在界面上吸附，促进界面张力降低，并且增强界面膜强度，导致乳状液稳定性增加，乳化性增强。

In order to explore the cause of serious emulsification of the Jimsar crude oil，the crude oil was separated into three components，including colloid，asphaltene，and remaining components，using precipitation and chromatographic separation methods.The elemental analysis of the crude oil and colloid was determined by elemental analyzer. The molecular composition of the heavy oil and the colloid was identified by electrospray technology（ESI）combined with high-resolution Fourier transform ion cyclotron resonance mass spectrometer（FT-ICR MS）. The results showed that the colloid content of the crude oil was 43.19%，the asphaltene content was 0.31% and the residual content was 56.5%. The elemental analysis results showed that the nitrogen content in the colloid was about 2.3 times as high as that of the crude oil，the content of O and S in colloid was 1.82 and 1.29 times as high as that of crude oil，indicating that the main emulsifying active components of Jimsar crude oil came from colloid. In the -ESI mode，the relative molecular weight of non-alkaline compounds was within 200—600 Da and the mass center of crude oil and colloid is at m/z= 350. The molecular structure type and relative abundance of various compounds in the mass spectrum were then analyzed. The content relation of each component in the mass spectrum was，N1>N1O1>N1O2>O2>O1. It is speculated that the higher content of carbazole（N1）compounds leaded to the increase of the emulsification and water-binding capacity of the crude oil；in addition，N1O1 and N1O2，the oxidation products of N1，increased the hydrophilicity，polarity and emulsification of the crude oil. The structure of O2 （acid）and O1（phenol）was also analyzed. Their existence further enhanced the emulsification ability of the crude oil. In the +ESI mode. The molecular weight of the alkaline compounds of Jimusar crude oil and its colloid was within 200—600 Da. The mass center of crude oil was at m/z=350，while the mass center of colloid was at m/z=340. In the +ESI mode，there were two types of nitrogen-containing heteroatoms，N1 and N2，of which N1 domained the absolute predominance，which may be compound of octahydroacridines，octahydrophenanthridines，quinolines or isoquinolines. Such substances enhanced the emulsifying ability of crude oil under acidic，neutral or high temperature conditions. It was inferred that the main cause of the serious emulsification of Jimusar shale oil was the polar components in the colloid，which had high interfacial activity and were easily adsorbed on the interface to promote the reduction of interfacial tension and the increase of interfacial membrane strength，hence was conducive to the stable existence of the emulsion.

10.19346/j.cnki.1000-4092.2022.04.011