东濮凹陷濮卫环洼带层序划分与沉积体系

根据地层基准面原理，通过对岩心、测井、录井资料的综合分析，将研究区Es3.3-Es3.2层段的地层划分出4个中期地层旋回（层序）：MSC1，MSC2，MSC3，MSC4。其中大致发育2种类型的层序，即陆源碎屑岩层序和膏盐岩层序。陆源碎屑岩层序多形成于基准面上升期，以发育泥质岩夹浊积砂体、三角洲前缘砂质沉积为主；膏盐岩层序多形成于基准面下降期，以发育厚层的盐岩、膏盐岩、膏岩、泥膏岩、膏泥岩夹浊积席状砂为特征。识别出3种类型的沉积体系：较深水湖－浊积扇、较深水盐湖、浅湖－三角洲体系，并在层序格架内分析了各旋回的沉积体系构成和储层砂体的发育情况。综合分析生、储、盖条件后认为，在垂向上，MSC2上升半旋回为本区最有利的储集层段；在平面上，本区的油气勘探应主要寻找洼陷东、西两侧断层下降盘的浊积砂体，主要储层砂体类型为浊积水道及浊积席状砂。

SEQUENCE DIVISION AND DEPOSITIONAL SYSTEMS OF PU-WEI AREA IN DONGPU DEPRESSION

Based on cores, logs and seismic data, four intermediate cycles(sequences) can be recognized in the studied strata with the principle of base\|level, which are called MSC1, MSC2, MSC3, MSC4 in descending order. There are two types of sequences in these cycles: clastic rock sequence and gypsum\|salt rock sequence. Clastic rock sequence is usually the product of base\|level rise hemicycles which are characterized by mudstones interbedded with turbidites and sandy deposits of delta front. Gypsum\|salt rock sequence is the product of base\|level fall hemicycles which are characterized by thick\|bedded halite,gypsite, gypsum\|salt rock, interbedded with sheet like turbidites. Three depositional systems are recognized, namely deep lake\|turbidite fan,deep water salt lake and shallow lake\|delta.Evolution and distribution of these depositional systems and facies are interpreted in these cycles. According to the characteristics of reservoirs, source rocks and cap rocks, the favorable reservoir members, facies and exploration zones are predicted.