论隆起背景对鄂尔多斯盆地陕北斜坡区三叠系油藏形成和分布的控制作用  

Controlling of Uplifts on the Triassic Petroleum Accumulation and Distribution in North Shaanxi Slope, Ordos Basin

作　　者：赵靖舟[1] 杨县超[2] 武富礼[1] 时保宏[1] 

机构地区：[1]西安石油大学,710065 [2]西北大学

出　　处：《地质学报》2006年第5期648-655,共8页Acta Geologica Sinica

基　　金：国家重点基础研究发展计划"973"项目(编号2003CB2146000)资助的成果。

摘　　要：传统认为,鄂尔多斯盆地陕北斜坡为一平缓的西倾单斜,构造简单,隆起构造不发育,因此构造因素对该斜坡三叠系延长组油藏的形成和分布不起主要控制作用,其三叠系延长组油藏的形成和分布主要受沉积相控制,油藏类型主要为岩性油藏。然而,随着勘探程度的提高,特别是随着钻井密度的加大(其目前井距一般已达100～200m左右),根据钻井资料进行的高精度构造编图研究发现,陕北斜坡隆起构造特别是低幅度的隆起构造实际上比较发育,且其类型主要为鼻状隆起,完整的穹隆构造较为少见且规模较小。就成因而言,一般规模较大、继承性好的隆起构造多与基底隆起有关,而小型隆起构造可能主要为差异压实成因。而且,隆起构造对三叠系延长组油气藏的形成与富集具有重要控制作用,尤其是规模较大的鼻状隆起构造附近,油气通常最为富集。As North Shaanxi Slope in the Ordos Basin is a large smooth monocline dipping westward and the structure are simple, it has traditionally been regarded that the Triassic petroleum accumulation and distribution in the slope are mainly controlled by sedimentary facies, and therefore, the type of the accumulations are lithologic, on which structural and other geologic factors are believed to have no important effect. Nevertheless, as the exploration degree or drilling density is increased （the distance between wells are now 100 m to 200 m）, the present authors find through structural mapping of high precision that the uplifts and nose-shaped uplifts in particular are acturally developed and have important controlling effect on the the Triassic petroleum accumulation and distribution in North Shaanxi Slope. And petroleum accumulations are especially enriched near the large nose-shaped uplifts. In fact, it has also been found that the formation and enrichment of the Triassic petroleum accumulations in the Slope are actually controlled by multiple factors, such as the background of nose-shaped uplift, sedimentary facies, the migration pathway, regional caprocks and hydrodynamics. Particularly, the background of nose-shaped uplifts is an important condition for the formation and enrichment of the Triassic accumulations; and the formation of the mid-large oil fields has close relations with such a structural backg round of nose-shaped uplifts. Consequently, the types of the Triassic accumulations in North Shaanxi Slope are complicated and multiple. Besides lithologic accumulations, the structure-lithologic and structure-hydrodynamic composite accumulations are possibly the mainly types. Therefore, the composite accumulations should be the major exploration targets in North Shaanxi Slope of the Ordos Basin.

关 键 词：隆起构造 三叠系 油藏类型 分布规律 陕北斜坡 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]