摘要
结合深水重力流沉积理论、野外剖面、岩心、测井等资料的分析,对鄂尔多斯盆地合水地区延长组长7油层组重力流沉积相和砂体结构的类型、特征进行了深入分析。研究表明长7沉积期发育大面积的深水砂岩,主要发育砂质碎屑流、浊流等重力流砂体,砂质碎屑流沉积以块状层理为主,单砂体厚度大,浊流沉积以粒序层理为主,砂泥互层频繁;结合重力流沉积背景下各成因砂体测井曲线形态、垂向发育厚度、垂向连续性及组合特征,将砂体垂向叠置结构划分为多期砂叠置厚层型、厚砂-薄泥互层型、厚砂-薄砂-泥互层型及薄砂-厚泥互层型四种类型,并对研究区单井砂体结构进行了聚类。实践表明,砂质碎屑流沉积区虽是油气藏有利聚集分布带,但分布面积较广,结合砂体结构特征,可进一步细化有利区划分,为致密油藏有利区的优选提供了新的研究思路。
This paper presents an analysis of field profiles, cores and logging data based on the theory of deep-water gravity flow deposition. Our purpose is to describe the types and characteristics of gravity flow sedimentary facies and sand architecture of Chang 7 Formation in the Heshui area of Ordos Basin. Research shows that a large-extent deep-water sandstone formed during the sedimentary period of Chang 7 in this area, dominated by sandy debris flow, turbidity flow. The sandy debris flow created massive beddings with thick individual sand bodies. The turbidity flow mainly produced graded beddings with many sand-mud interbeds. In light of logging curves, vertical thickness and continuity, and combination, the structures of sand bodies are divided into four types, i.e. overlaps of multiphase sands, interbeds of thick sand and thin mud, interbeds of thick sand, thin sand and mud, and interbeds of thin sand and thick mud. Then cluster analysis is made to sand-body structures of single wells in the study area. Research further shows that the sandy debris flows are favorable reservoir areas, but they are widely distributed. So they should be further subdivided based on the characteristics of sand architectures, which would shed a light on how to optimize favorable tight reservoir areas.
出处
《地质与勘探》
CAS
CSCD
北大核心
2018年第1期183-192,共10页
Geology and Exploration
基金
国家重大科技专项"鄂尔多斯盆地致密油开发示范工程"(编号:2017ZX05069)
中石油股份有限公司重大科技专项"长庆油田5000万吨持续高效稳产关键技术研究与应用"(编号:2016E-05)联合资助
关键词
鄂尔多斯盆地
长7油层组
重力流沉积
砂质碎屑流
浊流
砂体结构
Ordos basin, Chang 7 Formation, sediment of gravity flow, sandy debris flow, turbidity flow, sand architecture
