Analyses on the high recovery of Z37 reservoir in LFX13-1 Oilfield, Pearl River Mouth Basin

Abstract

The pay zone of Z37 reservoir in LFX13-1 Oilfield of Pearl River Mouth Basin is negative sequence massive sandstone from mouth bar of delta front. The development performance was characterized as rigid water-flooding, high productivity, high recovery rate and flat water cut rising-up at middle-high water cut stage. The recovery factor of Z37 reservoir is estimated above 70%. The production performance was evaluated as a whole from water cut rise-up rate, oil recovery rate and periodical oil recovery factor. The main reasons for the high recovery factor of Z37 reservoir were demonstrated and concluded from geological features, bottom aquifer size, well-pattern completion procedure and well pattern, the advantage of negative sedimentary sequence, hidden remaining oil catching at high water-cut stage, high in-situ temperature field improving displacement efficiency and rock wettability, horizontal well developing bottom-water reservoir, high crude oil price and application of many advanced technologies. The success production experience of Z37 reservoir can provide reference for the production of similar type of reservoirs. ： 珠江口盆地LFX13-1油田Z37油藏储集层为三角洲前缘河口坝反韵律块状砂岩，油藏开采表现出明显刚性水驱特征，具有油井产能高、采油速度高、中高含水期含水上升平缓等特点，预测最终水驱采收率将超过70%。从含水上升率、采油速度和阶段采出程度等方面对Z37油藏的开发效果进行了总体评价。从油藏地质特征、水体能量大小、完善开发井网的过程及方式、反韵律沉积层序优势、特高含水后期隐蔽剩余油的挖潜、高地温场对驱油效率及岩石表面润湿性的改善、大规模采用水平井、高油价的有利因素及众多相关前沿技术的应用诸方面剖析了Z37油藏取得高采收率的主要原因。Z37油藏的成功开采经验可为同类型油藏的开发提供借鉴。图9表2参14