摘要
由于反应途径或机制不同于裂解反应,硫酸盐热化学还原作用(TSR)很可能会改变油藏中原油的热稳定性和裂解气产量。为了阐明TSR作用对原油裂解气生成的影响,利用黄金管热模拟装置开展了一系列不同硫酸盐和原油的升温热解实验。非烃气体,包括H2S的大量生成表明,石膏和硫酸镁的加入引发了原油的TSR反应,其中,石膏参与的TSR作用对烃类气体的产量和生成活化能无明显影响;相对而言,硫酸镁参与的TSR反应引起了最终甲烷产量约13.1%的降低和大分子气态烃(C2+)稳定性的明显降低;氯化镁的加入导致了硫酸镁体系中H2S产量进一步的增加和烃类气体产量进一步的降低。可以证实,在硫酸镁热解体系中,C2+与活性结构HSO4-发生了氧化还原反应,这也是导致烃类气体产量降低的重要原因。因此,TSR作用对裂解气生成的影响很大程度上受控于地层水中的硫酸盐类型和活性结构的浓度。
Thermochemical sulfate reduction （TSR） might alter the stability of oils and the yield of cracked gas in reservoirs because its reaction pathway or mechanism differs from that of oil cracking. In order to ascertain the effect of TSR on the generation of cracked gas from oils, we performed a series of non-isothermal pyrolysis experiments involving different sulfates and an oil （QB3） with a gold-tube system. The generation of considerable amounts of non-hydrocarbon gases （including H2 S） indicates that TSR is in- itiated by the presence of gypsum and magnesium sulfate （MgSO4）. Comparatively, the yield and generation activation energy of gaseous hydrocarbons are not obviously affected by TSR involving gypsum. Whereas TSR involving MgSOg leads to about 13.1% decrease in the methane yield and also a remarkable decrease in the stability of C2＋ , and the addition of MgC12 to the MgSO4 system results in a further increase in the H2S yield but a further decrease in the hydrocarbon gas yield. Moreover, the redox reaction be- tween C2＋ and actively structured HNO4 - can take place in the MgSO4 pyroysis system, which is attributed to an important cause for decreasing the yield of gaseous hydrocarbons. Therefore, the effect of TSR on the generation of cracked gas is significantly domina- ted by sulfate types and the concentration of active species in formation water.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2013年第4期720-726,共7页
Acta Petrolei Sinica
基金
国家重大科技专项"天然气生成机理
资源潜力评价与战略选区"(2011ZX05007-001)
中国石油天然气股份有限公司科技项目"不同地质条件下油气生成排驱模型及在资源评价中的应用"(2011A-0201)
中石油咨询公司科技项目(2010D-5003-04)资助
关键词
硫酸盐热化学还原作用
原油
裂解气
接触离子对
活化能
thermochemical sulfate reduction
crude oil
cracked gas
contact ion-pair
activation energy
