鄂尔多斯盆地陇东地区长7段致密砂体重力流沉积模拟实验研究  

Research of simulated experiment on gravity flow deposits of tight sand bodies of Chang 7 Formation in Longdong area,Ordos Basin

作　　者：杨华[1,2] 牛小兵[1,3] 罗顺社[4] 冯胜斌[1,3] 吕奇奇[4] 

机构地区：[1]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [2]中国石油长庆油田公司,陕西西安710018 [3]中国石油长庆油田公司勘探开发研究院,陕西西安710018 [4]长江大学地球科学学院,湖北武汉430100

出　　处：《地学前缘》2015年第3期322-332,共11页Earth Science Frontiers

基　　金：国家自然科学基金项目(41172105);中国石油天然气股份公司重大科技专项"鄂尔多斯盆地致密油勘探开发关键技术研究"(2011E-2602-02);油气资源与勘探技术教育部重点实验室(长江大学)开放基金资助项目(K2013-19);国家自然科学基金重大项目(41390451)

摘　　要：致密砂岩目前已成为中国油气勘探开发的重点领域。以鄂尔多斯盆地陇东地区长7段为代表的典型致密砂岩主要发育辫状河三角洲和重力流沉积砂体,其中重力流沉积砂体具有很大的勘探开发潜力。在区域构造、古气候、古地貌和沉积体系等研究基础上,应用沉积模拟技术,再现了研究区长7段重力流沉积砂体形成过程及其主要控制因素,在实验条件下,半深湖-深湖区的沉积微相类型主要包括砂质碎屑流、浊积岩、深湖泥等。实验研究表明,影响重力流沉积砂体的形成及其演化的主要控制因素有:(1)泥砂含量决定了重力流的沉积类型;(2)湖盆底形控制重力流的砂体展布;(3)湖水位及流速决定重力流的沉积厚度及规模;(4)多物源交汇决定重力流的横向连通。并通过实验结果对比分析,预测了有利储集层分布区域。综合陇东地区原始地质模型和实验模拟成果,建立了沉积模拟实验条件下陇东地区三叠系长7段沉积模式。Tight sandstone has been an important field of exploration and development of oil and gas in China recently. The tight sandstones of Chang 7 Formation of Longdong area in Ordos Basin mainly developed into braid deltas and gravity flow sedimental sand bodies. And the latter has great potential in exploration and development. On the basis of research of regional structure, paleoclimate, ancient landform and sedimentary systems, we applied the technology of sedimentary simulation to recreating the formation processes and main controlling factors of the researched area, the Chang 7 Formation. Under laboratory conditions, sedimentary facies of semi-deep to deep lakes are mostly sandy debris flow, turbidite and deep lake mud. The experimental research indicates that the main controlling factors to impact the formation and evolution of gravity flow sedimental sand bodies are： （1）sediment concentration （decides the sediment type of gravity flow） l （2）the shape of the bottom of a lake basin （controls the distribution of sand body of gravity flow） ~ （3）the lake stage and flow rate （decide the sedimentary thickness and the scale of gravity flow） ~ （4）the intersection of various sources （decides the transverse connection of gravity flow）. Also, by analyzing and comparing the results of the experiment, we predicted the areas with favorable reservoir distribution. We combined the original geological model of Longdong area with the results of the simulated experiment and established the sedimentary pattern of Chang 7 Formation of the Triassic in Longdong area under the condition of sedimentary simulation experiment.

关 键 词：致密砂岩 沉积模拟 砂质碎屑流 浊积岩 陇东地区 延长组 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]