柯克亚凝析气田中新统西河甫组季节性河流沉积特征研究  

SEASONAL RIVER SEDIMENTATION OF XIHEFU FORMATION IN KEKEYA GAS CONDENSATE FIELD

作　　者：李华启[1,2] 姜在兴[3] 邱隆伟[3] 邓兴梁 赵少宇 鲁洪波[5] 

机构地区：[1]中国科学院广州地球化学研究所 [2]中国石油天然气股份公司,北京100011 [3]石油大学地球资源与信息学院 [4]中国石油塔里木油田分公司柯克亚作业区 [5]德克萨斯大学奥斯汀校区

出　　处：《新疆地质》2003年第1期69-73,共5页Xinjiang Geology

摘　　要：柯克亚凝析气田中新统西河甫组在沉积特征上与正常的曲流河相比较为相似,如具有较典型的二元结构、中等砂岩成熟度、两段式的概率累积曲线、以单向水流为主的牵引流占主导地位的沉积构造等,同时也具有一些特殊性:①未发现有植物根迹,也没有含煤地层出现,在河漫滩亚相中缺少沼泽微相.②存在异常水流活动以及指示洪水重力流作用存在的沉积构造;③存在能反映氧化、河流季节性活动以及干旱气候环境的丰富而独特的的遗迹化石组合,如Scoyenia组合和Skolithos组合等.上述特征反映其为干旱气候下的季节性河流沉积.Kekeya gas condensate field is located on the Kekeya anticline in southwestern Tarim depression. The sandstone of Xihefu Formation is the main reservoir of the gas condensate field. Xihefu Formation is a set of subaerial depositional sequence dominated by red, aubergine and brown sandstone, siltstone and mudstone. A lot of sedimentary structures that indicate unidirectional tractive current effect are present, such as large-scale parallel beddings, tabular cross-beddings, trough cross-stratifications, typical climbing ripple-beddings and wavy beddings, etc., as well as bedding structures such as aqueous current ripple mark, truncate ripple mark and lineation. Depositional characteristics such as typical binary structure, medium maturity of sandstone, grain size probability plot of two populations that mainly formed in meandering river are also common in the studied formation.In addition, the Xihefu formation also has some sedimentological particularities. (1) Almost all sedimentary rocks in studied area are red, aubergine or brown, with no fossil of plant root and coal-bearing strata, and no marsh microfacies in overbank subfacies which is common in a typical meandering stream. (2) There exist sedimentary structures showing the activity of abnormity current and flood gravity flow, such as graded bedding, flute casts and deep mud crack, etc. And matrix-supported gravels can sometimes be found in sandstone and mudstone. (3) Trace fossils are abundant, such as Scoyenia,Skolithos,Muensteria,Cylindricum,Palaeophycus or Planolites, among which Scoyenia and Skolithos are most abundant. Scoyenia is a familiar trace fossil in red beds, which is common in sand or mud sediments deposited in shallow lake and river. The typical environment of the trace fossil is the shallowest lake and river which exists near fresh water surface with seasonal exposure and flooding.Skolithos develops in medium to high energy environment, whose sedimentary substrate is clean and well-sorted sand. In a terrestrial basin, the trace fossil mainly

关 键 词：柯克亚凝析气田 塔里木盆地 季节性河流 沉积特征 遗迹相 遗迹化石 

分 类 号：P618.13[天文地球—矿床学]