辽河稠油蒸汽吞吐条件下降黏规律研究  

Study on Thermal Cracking for Liaohe Heavy Oil during Steam Soak

作　　者：张贵才[1] 潘斌林[2] 葛际江[1] 张焕芝[1] 

机构地区：[1]中国石油大学石油工程学院,山东东营257061 [2]胜利油田地质科学研究院采收率室,山东东营257015

出　　处：《油田化学》2007年第1期19-23,共5页Oilfield Chemistry

基　　金：2005年山东省科技攻关重大专项"特殊油藏提高原油采收率关键化学品制备及配套装备研究"(项目编号2005GG2107002)

摘　　要：对辽河稠油在蒸汽吞吐中发生的热裂解行为进行了室内实验研究。在高压反应釜中模拟热采时的井下条件,从四组分(SARA)、70℃降黏率、裂解气组成的角度分别考察了反应温度、反应时间、加水量对辽河稠油热裂解降黏效果的影响。结果表明:辽河稠油在250℃已开始发生裂解;在蒸汽吞吐条件下,SARA组成发生变化,轻质组分增加,胶体体系受到破坏,稠油黏度降低;稠油降黏率与反应温度成线性关系,温度从250℃升至350℃反应16 h的降黏率由32.03%升至98.82%;在350℃反应时间由1 h增至24 h,降黏率从38.67%升至99%。反应时间超过16 h后降黏率增长趋势变缓并趋于恒值,在其他温度下稠油黏度的变化有相同的规律,降黏率与反应时间的关系可以用同一公式表示;稠油热处理后降黏效果越好产生裂解气越多,裂解气含H2S也越多;水的存在对辽河稠油裂解有影响,当加入的水完全汽化时(本实验中加水量为稠油质量的10%时),降黏效果最好。蒸汽吞吐开采中稠油可在一定程度上实现永久性降黏。图3表8参6。The thermal cracking （ThC） of Liaohe heavy crude oil （LHCO） in the course of steam soak is investigated experimentally. Under simulation downhole conditions of steam huffing-puffing wells in an autoclave, the effects of ThC temperature and time and water charge on viscosity reduction （VR） of cracked LHCO are studied in terms of analyses of SARA and craking gas composition and determination of VR rote at 70℃. The results of this study are presented as follows. The ThC of LHCO can proceed at temperatures as low as 250℃. Under conditions of steam soak, the SARA composition of LHCO undergoes changes, which lead to an increase in light fractions, to destroying petroleum colloid system in some extent and to reducing viscosity of LHCO. The VR rote for LHCO cracked in 16 hrs is linearly proportional to ThC temperature and increases notably from 32.03 % to 98.82 % with raising ThC temperature from 250℃ to 350℃ ; when ThC time is 〉 16 hrs, the VR rate changes slowly and approaches to some constant value. At ThC temperature 350℃, the VR rate increases from 38.67% to 99.10% with ThC time increasing from 1 to 24 hrs. The changes in viscosity of LHCO cracked at temperatures other than 350℃ are similar and the relationship between VR rate and ThC time can he expressed by the same equation of fit. The more significant the VR of cracked LHCO the more cracking gas is formed and the more H2S exists in cracking gas. The presence of water affects the ThC reactions of LHCO and the VR of cracked LHCO reaches the highest extent when the water introduced is completely evaporized in the reaction vessel, or, in this study, when water is introduced in amount of 10% LHCO mass. The viscosity of heavy oils can he reduced permanently during steam soak.

关 键 词：稠油 降黏 改质 井下热裂解 水热裂解 反应条件 蒸汽吞吐 辽河油田 

分 类 号：TE624.31[石油与天然气工程—油气加工工程] TE357.44