为了查明海塔盆地中部断陷带潜山成因机制及成藏特征,研究断裂与潜山的配置关系,并通过对断裂系统的解剖,总结断裂系统对潜山成藏的控制作用。海塔盆地中部断陷带潜山按成因机制共分为3个大类8个亚类,其构造形态主要受Ⅰ型(早期伸展断裂系统)、Ⅰ-Ⅱ型(早期伸展中期张扭断裂系统)和Ⅰ-Ⅱ-Ⅲ型(早期伸展中期张扭晚期反转断裂系统)共3种断裂系统控制,其中Ⅰ型断裂系统为早期形成的断裂,促进潜山裂缝储层的发育,并作为遮挡边界有利于油气聚集,同时使潜山与烃源岩对接形成单、双向2种供烃模式,因此,Ⅰ型断裂系统控制的潜山是勘探的有利目标;Ⅰ-Ⅱ型和Ⅰ-Ⅱ-Ⅲ型断裂系统属于多期活动的断裂,控制潜山的形成及演化,更易形成裂缝密集带,但由于断裂多期的活动易导致油气散失,且不利于"供烃窗口"的形成,断裂控储与控藏具有不一致性,故对潜山油藏以破坏作用为主。
To clarify the genetic mechanism and hydrocarbon reservoir forming characteristics of Buried hills at middle fault depression belt in Hailer--Tamtsag Basin, allocation relations between fault and buried hill were studied through the analysis of fault system. Oil accumulation in buried hill which is controlled by fault systems was summarized. According to the genetic mechanism, buried hill of Hailer-Tamtsag Basin can be classified into three categories including eight subclasses whose structural form is mainly affected by three kinds of fault systems control, namely the type Ⅰ (early extensional fault system), type Ⅰ-Ⅱ (early extensional-middle tense-shear fault system), type Ⅰ-Ⅱ-Ⅲ (early extensional-middle tense-shear late reverse fault system). Type Ⅰ fault system is formed by one time early break to promote the development of the buried hill reservoir, and as the block boundary which is conducive to hydrocarbonaccumulation in buried hill hydrocarbon. It also forms two kinds of source rocks for hydrocarbon mode: unidirectional and bidirectional. Therefore, 1 type fault system in the control of buried hill is the favorable exploration target; type Ⅰ-Ⅱ and Ⅰ-Ⅱ-Ⅲ fault systems are the fracture of the long-term activities. Though the control the formation and the evolution of the buried hill make it easier to form cracks dense zone, faults of activities damage the reservoir and are not conducive to "hydrocarbon-supplying window" formation. As a result, fault controlled reservoir and hydrocarbon are inconsistent, which destroy the buried hill oil reservoir mainly.