海上薄互层砂岩油藏层间干扰规律及调整对策

Interlayer Interference Pattern and Adjustment Countermeasures of Offshore Thin Interbedded Sandstone Reservoirs

薄互层砂岩油藏储层复杂,层间干扰主控因素多样,层间干扰规律难以预测,严重影响了油田整体开发效果。针对该问题,基于薄互层砂岩油藏层间干扰作用机理,通过油藏工程方法,明确了薄互层砂岩油藏层间干扰主控因素;结合实际油田生产动态分析,量化评价了小层动静态流动能力,建立小层物性、流体性质、注采受效程度及水淹程度等多重因素共同作用下的层间干扰全寿命定量预测图版,并提出有针对性的层系调整对策。研究表明:薄互层砂岩油藏不同流动能力差异下层间干扰呈现不同的动态变化规律,需综合考虑动静态因素的影响;流动能力差异系数7.0以内的小层初期层间干扰相对较弱,可划分同一层系开发,中高含水期后强水淹小层将显著加剧层间干扰作用。该研究对指导薄互层砂岩油藏层系划分及调整具有借鉴意义。

Thin interbedded sandstone reservoir is disadvantaged by complicated conditions,various main controlling factors of interstratigraphic disturbances,and difficult prediction of interstratigraphic disturbance law,exerting great impact on the overall development efficiency of the oilfield.To address this problem,based on the mechanism of interlayer interference in thin interbedded sandstone reservoirs,the main controlling factors of interlayer interference in thin interbedded sandstone reservoirs were clarified by reservoir engineering methods.According to the dynamic analysis of actual oilfield production,the dynamic and static flow capacities of the sub-bed was quantitatively evaluated,a quantitative prediction chart was prepared for interlayer interference throughout the whole life under the joint action of physical properties,fluid properties,injection and production effects,water logging and other factors of the sub-bed,and targeted countermeasures for bed series adjustment were proposed.It was found in the study that,the interstratigraphic disturbances in thin interbedded sandstone reservoirs exhibited different dynamic patterns under different flow capacities,and the effects of dynamic and static factors should considered comprehensively;interstratigraphic disturbances in sub-beds with flow capacity difference coefficients of 7.0 or less are relatively weak at the initial stage,and such sub-beds could be considered as one system for development;the interstratigraphic disturbances were intensified in the sub-beds under heavy water flooding after the medium and high-water-cut stage.The study results have an exemplary significance regarding the division and adjustment of thin interbedded sandstone reservoirs.