阿尔及利亚Oued Mya盆地438B区块下泥盆统储层沉积学特征

Characteristics of the Lower Devonian reservoir sedimentology in Block 438B,Oued Mya Basin,Algeria

利用钻井岩心、测井资料和层序-岩相古地理编图,研究了阿尔及利亚Oued Mya(韦德迈阿次)盆地438B区块下泥盆统储层沉积学特征。该盆地是一个富含油气的古生代-中生代叠合盆地,438B区块地处盆地西北部,区块内下泥盆统发育有陆棚和障壁岛-滨岸2个沉积体系,具备良好的油气生、储、盖组合和勘探开发潜力。其中障壁岛-滨岸沉积体系由障壁砂坝、潮汐通道、冲溢扇、潟湖、潮坪等沉积微相组成。以储层沉积学分析为基础的储层预测和评价结果,表明储层发育主要受高位体系域的障壁砂坝和冲溢扇沉积微相控制。这2个沉积微相可列为主要的勘探目标。

By using drilling cores,logging data and sequence-lithofacies palaeogeography mapping techniques,the authors make a detailed study on the characteristics of Lower Devonian reservoir sedimentology in Block 438B,Oued Mya Basin,Algerian in this paper.Block 438B is located in north-central Oued Mya Basin.It is a Paleozoic-Mesozoic superimposed basin rich in oil and gas.In Block 438B,There develop two types of depositional systems of continental shelf and barrier island-shore in the Lower Devonian.They have a good hydrocarbon source-reservoir-cap assemblage and exploration potential.The barrier island-shore system is composed of barrier sand dams,tidal channels,washover fans,lagoons and tidal flats.The results of reservoir prediction and evaluation based on the reservoir sedimentology indicate that the reservoir is mainly controlled by barrier sand dam and washover fan microfacies during HST.The two sedimentary microfacies are the major exploration targets.