Oriente盆地L-I-Y油田Hollin组与Napo组沉积微相研究

摘要

The Cretaceous Hollin and Napo formations are the main layers for exploration and development in the L-I-Y Oilfields (Limonocha,Indillana,and Yanaquincha Oilfields).It has been proven that sedimentary microfacies are key not only for controlling the fulfillment of exploration and development adjustment wells but also for controlling single well productivity and exploitation benefit.Based on core,well logging,and mud logging data,different types of sedimentary microfacies are identified in our study.Using seismic attributes such as waveform clustering,the seismic response of different types of sedimentary microfacies and their plane distribution characteristics are further discussed in this study.The HP and HS subsections of the Hollin formation and the TP,TS,UI,UM,and US subsections of the Napo formation are primarily deposited under a tidal flat environment,while the CL,BL,and AL subsections of the Napo Formation are primarily deposited under a shallow shelf environment.These two environments can be further divided into four subfacies and thirteen microfacies.The subtidal zone dominates the tidal flat environment,followed by the intertidal zone,and the supratidal zone,which is undeveloped.Tidal channels and sand flats are the most favorable microfacies for oil and gas accumulation and high-quality reservoir development.A favorable sedimentary microfacies well developed in the H section of Hollin formation,where only a small number of wells have been encountered so far,which makes it a significant target for future exploration.%白垩系Hollin组与Napo组是Oriente盆地L-I-Y油田(Limonocha,Indillana,Yanaquincha油田)主要勘探开发层系,多年勘探开发实践证明,其沉积微相是决定勘探井与开发调整井成功与否的关键因素之一,并影响着单井产能与开发效益.为此,将地质与地震相结合,在利用岩心、测井、录井等资料精细识别和划分不同沉积微相特征的基础上,通过井震精细标定和正演模拟,明确了不同沉积微相地震响应特征,运用波形聚类等地震属性,精细描述了主要目的层段沉积微相平面展布.研究认为:Hollin组HP,HS亚段和Napo组TP,TS,UI,UM,US亚段为潮坪沉积环境,Napo组CL,BL,AL亚段为陆棚沉积环境,进一步分为4种亚相、13种微相;在潮坪沉积环境中,潮下带最发育,其次为潮间带,潮上带不发育,潮道、潮道侧积砂坪为最有利沉积微相,控制着优质储层发育区带和油气富集;Hollin组H段有利沉积微相发育,目前钻井相对较少,具有较大的勘探开发潜力,是下一步重点勘探开发层系.