低渗透油藏地质工程一体化高效建产--以东营凹陷N25区块为例

High-efficient Development of Low-permeability Reservoir with Geology and Engineering Integration:a Case Study of N25 Block in Dongying Sag

东营凹陷低渗透油藏分布散、埋藏深、品位低,开发过程中注不进、采不出矛盾突出,效益建产面临单井产能低、自然递减大、采收率低等问题,高效开发难度大。以东营凹陷牛庄洼陷沙三段中亚段N25-42A低渗透浊积砂岩油藏为例,通过实施以储层精细刻画、复杂缝网压裂改造储层、正向压驱注水补能、钻井与地面工程优化设计施工为核心的地质工程一体化建产方案,有效提高地质甜点刻画精度,大幅缩短钻井周期,形成复杂缝网提高波及体积,快速补充地层能量,改善驱油效果。N25区块实施地质工程一体化建产方案后,平均单井产油量增加0.6倍,单井控制可采储量增加6倍,实现少井高产,投资大幅缩减。实践证明,地质工程一体化开发技术对于提升断陷盆地低渗透油藏的动用率、推动低品质油藏的产能建设具有一定应用价值和参考意义。

The development of the low-permeability hydrocarbon reservoirs in Dongying Sag,characterized with dispersed distribution,deep burial depth and low quality,face the prominent contradictions of injection failure and production failure,which lead to challenges for benefit development,such as low single-well productivity,rapid natural decline of production and low recovery efficiency,increasing the difficulty to efficiently utilization.Taking the N25-42A low-permeability turbidite sandstone reservoir of middle submember of Member 3 of Shahejie Formation in Niuzhuang subsag as an example,the implementation of the geology-engineering integration development strategy with fine reservoir characterization,reservoir stimulation through complex fracture network fracturing,forward pressure-driven water injection,optimized design and construction of drilling and ground engineering as the core,improves the sweet spot detection accuracy,significantly shortens the drilling cycle,stimulates the formation of complex fracture network and swept volume,efficiently replenishes the formation energy,and promotes the displacement efficiency.Since the application of the geology and engineering integration development strategy,the N25-42A low-permeability reserves realizes less wells but high yields and sharp reduction of investment,with the average daily oil production and the estimated ultimate recovery of single well increases by 0.6 times and 6 times respectively.Practice has proved the application value and reference significance of the geology-engineering integration development strategy in improving the utilizing rate of low-permeability reserves in fault basins,and promoting the capacity construction of lean reservoir.