摘要
将松辽盆地的地层纵向分为：浅部处于未成岩或早成岩阶段的砂泥岩，为疏松地层；中部处于早成岩晚期到晚成岩中期阶段的泥质岩、砂质岩，泥质岩为塑性地层，砂质岩为脆性地层；深部成岩作用深于晚成岩中期阶段的沉积岩及基岩，为脆性地层。疏松地层本身对流体纵向渗流没有封闭性，其中的断裂对油气运移也不起作用。塑性地层中断裂的活动性控制其导流性，活动期发生断移时，流体以涌流方式沿瞬间开启的断裂向上喷射，断裂停止活动即对流体形成纵向封闭。脆性地层中断裂带是否经历改造作用是影响其导流性的关键因素，若因同期改造作用（松辽盆地主要表现为泥质岩填充和涂抹）或后期改造作用（矿化和再成岩作用）而致密，大多对流体纵向运移形成封闭，否则一般成为流体长期纵向运移的通道，流体沿断裂带向上近似直线渗流。中部地层有大量砂泥岩薄互层段，若泥质岩比例高，断裂导流性近于塑性地层；若砂质岩比例高，流体沿断裂两侧砂岩层折曲渗流。结合松辽盆地地层特点和成岩演化程度，建立了盆地断裂纵向导流模式。照片５图１参７（梁大新摘）
Formations in Songliao basin can be vertically divided into ①Shallow formations which did not to any diagenesis or little diagenized and is crisp in character; ②Middle formations including those argillaceous and sandy layers in a period from late stage of early diagenesis to middle stage of late diagenesis, in these formations, argillaceous ones are plastic in nature, and those sandy ones are brittle; ③Deep formations: including those deposits ed to diagenesis after middle stage and basic rocks, and these formations are brittle in nature. Crisp formations had no action on vertical seepage of hydrocarbons and no capping action by the fault systems in them; the activity of fault system in plastic formations controlled the flow activity of fluids, during the fault and movement in their active stage, fluids flowed vertically upwards in the form of gush along the fractures opened instantly, and vertical closures to the fluid movement formed after the stop of faulting and fracturing. Key factor affecting the flow activity of the fracturing and fracturing zone in brittle formations is whether these zones have been reconstructed. If contemporaneous reconstruction (filling of argillaceous rocks is the main form in Songliao basin) or reconstruction in later stage (mineralization and rediagenesis) caused these faults and fractures to close, most of them gave closures to the vertical migration of fluids, otherwise they could form long term channels for vertical migration and fluids would migrate upward vertically in the form of linear seepage. There are large amount of thin interbedded sand and mud stones in the middle formations, if the ratio of argillaceous stone is high, the flow activity approaches those in plastic formations; and if the ratio of sandstones is high, fluids can seep along the sandstones on both sides of fault and fractures zigzagly. A model of vertical flow activity in the basin is this established according to the characteristics of formations in Songliao basin and the degree of diagenesis and evolution. Subject
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
1999年第1期32-35,共4页
Petroleum Exploration and Development
关键词
油气运移
断裂
纵向导流性
松辽盆地
Songliao basin, Formation, Fracture, Flow conductivity, Vertical diversion patterns
