海拉尔盆地呼和湖凹陷下白垩统层序构成样式及油气成藏模式

分析在不同构造背景下发育的层序构成样式，可以更加精确地预测有利勘探区带和油气藏。利用地震、钻井、测井、岩心以及古生物等资料，依据层序界面特征，将呼和湖凹陷下白垩统划分为3个二级层序、5个三级层序。依据构造背景，将研究区划分出断控陡坡带、缓坡断阶带、洼槽带等3种构造单元，在此基础上分不同构造单元建立了相应的层序构成样式:断控陡坡型层序构成样式、缓坡断阶型层序构成样式、洼槽型层序构成样式。研究结果表明，不同的构造单元具有各自特征的层序构成样式和沉积体系域构成模式，不同类型层序构成样式也决定了不同的构造单元具有不同的油气成藏模式。在断控陡坡带主要发育断层-岩性和断鼻型油气藏，在缓坡断阶带发育断层-岩性和地层超覆型油气藏，在洼槽带主要发育自生自储型的透镜体油气藏;此外，洼槽边缘可发育断层-岩性型油气藏。

Sequence Architecture Pattern and Pool-Forming Pattern of Lower Cretaceous in Huhehu Depression

Favorable exploration areas and oil and gas reservoir can be predicted more accurately though analysis of sequence architecture pattern in different tectonic settings.Using seismic,drilling,logging,core,paleontology and so on,according to sequence interface characteristics,Lower Cretaceous in Huhehu depression is divided into 3 second-order sequences,5 third-order sequences.On the base of structure background,Huhehu depression is divided into fault controlled steep slope zone,gentle slope fault terrace zone and depression zone.Different tectonic units show different sequence architecture patterns: fault controlled steep slope zone sequence architecture patterns,gentle slope fault terrace zone sequence architecture patterns and depression zone sequence architecture patterns.The results show that different tectonic units have specific characteristics of sequence architecture patterns and sedimentary system composing model,and different types of sequence architecture patterns control oil-gas formation models.Fault-lithology oil and gas reservoir,fault oil and gas reservoir mainly develop in fault controlled steep slope zone sequence architecture patterns;Fault-lithology oil and gas reservoir,and stratigraphic overlap oil and gas reservoir mainly develop in gentle slope fault terrace zone;Authigenic reservoir lens reservoir mainly develops in depression zone.Moreover,depression edge can develop fault-lithology oil and gas reservoir.