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

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.