顺向断坡油气藏分布特征及成藏主控因素--以孤北斜坡为例

Distribution and main controlling factors of hydrocarbon reservoirs in consequent fault-slope-a case study of Gubei Slope

以孤北斜坡为例,对顺向断坡的断裂展布、油气藏分布特征及成藏主控因素进行了研究。综合研究表明,顺向断坡同沉积断层的不断活动控制了孤北斜坡"一带一洼三台阶"构造格局的形成,产生了多级断裂坡折带,从而控制了各类扇体的沉积和岩性岩相的分布,为形成隐蔽油气圈闭准备了可容纳空间。在顺向断坡背景下,受断裂产状的控制,油气藏沿顺向断裂展布,并且分布于向斜坡倾向凸出的油源断裂的上倾部位;在此基础上,总结了断面优势运移模式。断裂的控圈控相和控运作用,使断裂成为断坡控制油气运聚成藏和分布的主要因素。

Faults system,hydrocarbon reservoir distribution and its main controlling factors in consequent fault-slope were researched taking Gubei Slope as an example.Comprehensive research shows that continuous activity of contemporaneous fault at the consequent fault-slope controlled the forming of the tectonic style of 'one belt one sag and three steps' which resulted in multiple slope-break belts and controlled the distribution of each type of fan deposit and lithologic facies.The structure prepared accommodation space for subtle oil-gas traps.The oil-gas pools,whose location was controlled by the attitude of the consequent faults,distribute along the consequent faults under the background of the consequent fault-slpoe.and the updip position of oil-source faults embossed to slope trend has more oil-gas pools.According these,the pattern of dominant migration along fractured surface was summarized that faulting was the main factor controlling the formation and distribution of oil-gas reservoirs along the consequent fault-slope because of its control action on traps,facies and migration.