鄂尔多斯盆地陇东地区三叠系延长组长7油层组致密砂岩沉积特征  

Sedimentary characteristics of tight sandstone in Chang 7 Member,Triassic Yanchang Formation in Longdong,Ordos Basin

作　　者：姚泾利[1,2] 耳闯[3,4] 齐亚林[1,2] 赵靖舟[3,4] 黄锦绣[1,2] 白卓立 

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [3]西安石油大学地球科学与工程学院,陕西西安710065 [4]陕西省油气成藏地质学重点实验室,陕西西安710065

出　　处：《西安科技大学学报》2016年第4期497-506,共10页Journal of Xi’an University of Science and Technology

基　　金：国家重大科技专项(2011ZX05044);国家科技重大专项(2011ZX05001-004)

摘　　要：陇东地区是鄂尔多斯盆地致密油的重要产区之一，砂体成因类型包括砂质碎屑流、浊流和滑塌。针对陇东地区长7油层组，利用X井长7全井段取心资料，分别开展了厘米级砂体成因解释（小尺度）、不同成因（期次）砂体组合解释（中尺度）和测井相解释（大尺度）。通过厘米级砂体成因解释，识别砂质碎屑流成因砂体366层，单层厚度以0．3m以下居多；识别浊流成因砂体225层，单层厚度以0．1m以下居多；识别滑塌成因砂体91层，单层厚度以0．15m以下居多。通过不同成因（期次）砂体组合划分，识别砂质碎屑流成因砂体共106层，浊流成因砂体共37层，滑塌成因砂体共38层。通过测井相组合解释，砂质碎屑流成因砂体厚度范围是0．6～6．03m，浊流成因砂体厚度范围是0．6—6．14m，滑塌成因砂体厚度范围是0．46～1．26m．从各尺度砂体类型（或组合）厚度和层数2方面综合分析，砂质碎屑流成因砂体是长7主要的的砂体类型。各类型砂体的发育规律与中期基准面有较好的响应关系，砂质碎屑流成因砂体在中期基准面上升早期和下降晚期发育程度最高，浊流成因砂体在中期基准面上升早期一下降早期发育程度较好，滑塌成因砂体在中期基准面上升早期和晚期较发育。Longdong is one of tight oil product area in Ordos Basin. Genetic types of sandstone of Chang 7 member in this area include sandy debris flow, turbidity flow, and slump. Using whole well interval core of Chang 7 Member in Well X,genetic types of sandstone were divided in 3 , core description levels, including micrometer-scale （ small scale）, combination of different genetic type or period （ middle scale ）, and combination of log facies（ large scale）. Through small scale description, 366 layers of sandy debris flow sandstone ,225 layers of turbidity flow sandstone ,and 91 layers of slump sandstone were identified. Thicknesses of most layers of every genetic type are thinner than 0.3 meter,0.1 meter and 0.15 meter, respectively. Through middle scale description, 106 layers of sandy debris flow sandstone combinations, 37 layers of turbidity flow sandstone combinations, and 38 layers of slump sandstone combinations were identified. Based on large scale description,thickness ranges of the 3 genetic types sandstone combinations divided by logs are 0.6 to 6.03 meters,0.6 to 6.14 meters,and 0.46 to 1.26 meters. The devel- opment law of each kinds of sandstone genetic is well corresponding to middle basic level cycles. During middle base level cycle,sandy debris flow was the dominate type under early stage of rising hemi-cycle and late stage of falling stage. Turbidity flow developed more common under late stage of rising hemi-cycle and early stage of falling hemi-cycle. Slump developed more common under early and late stage of rising hemi-cycle.

关 键 词：长7油层组 致密砂岩 砂体成因 重力流沉积 鄂尔多斯盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]