摘要
原油的物性和地化特征是油气成藏过程的综合反映,能预测油气运移距离、母源性质、保存条件等成藏要素。将溱潼凹陷的原油划分为超重油、重质油、中质油三类。平面上,相同层系的原油从深凹带向外斜坡带物性逐渐变差、成熟度降低,含硫量增加。纵向上,从深层向浅层原油物性逐渐变差。原油成熟度与形成环境具有良好相关性,低熟原油形成于咸化泥灰岩。外斜坡普遍发育低成熟油,深凹带阜二段烃源岩在三垛初期生成低熟油,三垛末期生成成熟油,低熟油先充注,后期成熟原油驱替低熟油不断运聚到外斜坡成藏。溱潼凹陷斜坡带油源比较充足,原油经过较长距离运移,阜三段剥蚀带也是有利的勘探区。原油物性受油源、油气运移、氧化作用、生物降解等因素影响,油源差异和油气运移对原油物性的环带状分布起主要作用,而保存条件对于局部原油物性变化起重要作用。
The physical properties and geochemical characteristics of crude oils are comprehensive reflections of the hydrocarbon accumulation process and enable migration distance,parent properties and preservation conditions to be predicted.Crude oils from the Qintong Sag are categorized into super-heavy oil,heavy oil and medium oil,depending on their physical properties and geochemical characteristics.From the deep sag to the outside slope,the physical properties of the crude oil in the same stratum worsen,sulfur content increases,and maturity decreases.Also the physical properties of the crude oil gradually deteriorate from deep to shallow.According to this comprehensive study,the maturity of the crude oil correlates closely with the formation environment:low-maturity crude oil is found in salinized source rock,and is generally found at the outside of the slope.This is the result of early hydrocarbon generation in the source rock of the deep sag zone;in the latter stage,low-maturity oil is continuously driven towards the middle and outer slopes by the mature crude oil.It is indicated that the oil of the third member of the Funing Formation in the Qintong Sag slope zone is relatively abundant.The crude oil is transported over a long distance,and thus the denuded zone on the outside slope is a favorable exploration area.The distribution of the physical properties of the crude oil in the slope zone is affected by oil source,hydrocarbon migration,oxidation,biodegradation,and so on.Oil source differences and hydrocarbon migration play a major role in the annulus distribution of crude oil properties,while preservation conditions play an important role in creating local differences in the physical oil properties in individual reservoirs.
作者
昝灵
柴方园
印燕铃
ZAN Ling;CHAI FangYuan;YIN YanLing(Research Institute of Exploration and Development,Petroleum East China Company,SINOPEC,Nanjing 210019,China)
出处
《沉积学报》
CAS
CSCD
北大核心
2021年第5期1068-1077,共10页
Acta Sedimentologica Sinica
基金
国家科技重大专项(2017ZX05049001-004)
中石化科技项目(P20049-3)。
关键词
溱潼凹陷
斜坡带
原油物性
油气运移
成藏过程
Qintong Sag
slope zone
physical property of crude oil
oil migration
accumulation process
