幔源CO_2充注驱油机理——以松辽盆地南部长岭凹陷为例  

Mechanism of mantle-derived carbon dioxide infilling and oil displacement:a case studying in Changling sag of southern Songliao Basin

作　　者：刘东舟[1] 彭晓蕾[1] 刘立[1] 于淼[1] 徐思萌 

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《世界地质》2015年第1期142-147,共6页World Geology

基　　金：国家科技重大专项(2011ZX05016-002);吉林省科技发展计划重点项目(20110426)联合资助

摘　　要：分析天然气(CH4)驱油、原油驱水原理,建立了幔源CO2流体的充注驱油模型,在模型中CO2能否形成足够驱动力是驱油的关键。松辽盆地南部长岭凹陷泉四段储层与该模型相符合,在储层中发现幔源CO2与油气混层现象,并且CO2充注时间晚于油气注入时间。根据研究区地质条件,对幔源CO2驱油动力和阻力以及影响其大小的参数(CO2与原油的密度、界面张力、孔喉半径和CO2柱高度)进行分析,得出幔源CO2与原油所产生的浮力足可以突破油气运移阻力(毛细管阻力)。从物理和数学的角度证明幔源成因CO2能够对油气运移起到推动作用。Through the analysis on the theory of natural gas（ CH4） displacement and oil driving water,we established the model of mantle-derived CO2-bearing fluid infilling and displacement. The key of the model is whether CO2 could form sufficient driving force. The fourth-member of Quantou Formation reservoir in Changling sag of southern Songliao basin is matched with the model,and we found the mixed layers of mantle-derived CO2 and oil-gas,moreover,the infilling of oil and gas was earlier than that of CO2. According to the geological conditions of the studied area,we analyzed the driving and resistant force as well as the parameters which related to them,such as original CO2 density,interfacial tension,pore throat radius and CO2 column height. We concluded that the buoyancy created by mantle-derived CO2 and crude oil is enough to break through the migration resistance（ i. e.,capillary resistance）. It can be proved that mantle-derived CO2 plays a promoting role in the migration of oil and gas in perspectives of physics and mathematics.

关 键 词：幔源成因CO2 驱油机理 浮力 毛细管压力 长岭凹陷 

分 类 号：P618.130[天文地球—矿床学]