摘要
轮南地区是塔里木盆地重点产油气地区之一,对其下奥陶统碳酸盐岩储层性能及分布的研究具有重要的实际意义。通过对研究区岩溶、裂缝发育、沉积和洞穴充填物分析研究,认为具渗透可溶性碳酸盐岩及温暖潮湿、多大气降水是岩溶储层形成的必要条件,构造裂缝的发育为岩溶储层发育创造了有利条件。根据裂缝性质及充填程度,本区裂缝可分为方解石完全充填张裂缝、方解石半充填张裂缝、泥质充填扭压性裂缝、未充填微细裂缝和缝合线5种,其中方解石半充填裂缝和缝合线对储层岩溶发育起重要作用。本区岩溶具明显的垂直分带性,可分为垂直渗流岩溶带、水平潜流岩溶带和过渡带,其中垂直渗流带底部及水平潜流岩溶带上部储集物性最佳。轮南地区发育的两期岩溶与石炭纪两次较大的海侵时间相一致。作者还研究了充填物的沉积特征,探讨了储层的演化模式。
The Lunnan area is one of the important oil and gas producing areas in the Tarim Basin. Study of reservoir characteristics of Lower Ordovician carbonate rocks is important to oil and gas exploration. The features of karst, development of fractures, sedimentary facies and filling materials in caves were des-cribed . Existence of permeable and soluble carbonate rocks, humid climate and abundant precipitation are considered to be necessary conditions for forming karst. Development of structural fractures is favorable for karst development. According to the property of fractures and filling degree, the fractures are divided into five types, such as calcite full-filled extension fractures, calcite semi-filled extension fractures, clay filled shearing compressive fractures, non-filled micro-fractures and stylolites, among which calcite seim-filled extension fractures and stylolites play an important role in development of karst reservoirs. Development of karst in this area shows obvious vertical zonation, i. e. the vertical vadose zone, the horizontal phreatic zone and the transitional zone. At the bottom of vertical vadose zone and the top of the horizontal phreatic zone, the properties of reservoir are best. The two karst developing periods for the Middle and Upper Or-dovician in the Lunnan area are consistent with two transgressions of the Carboniferous. The sedimentary features of filling materials in caves were also described and the evolutional model of karst was estab-lished .
出处
《古地理学报》
CAS
CSCD
1999年第1期54-60,共7页
Journal of Palaeogeography：Chinese Edition
关键词
塔里木盆地
下奥陶统
碳酸盐岩
岩溶
储层特征
裂缝
沉积相
储层
Tarim Basin, Lower Ordovician, carbonate rocks, karst, fractures, sedimentary facies, reservoirs
