渤海典型多层砂岩油藏中高含水期定向井产能预测新方法

A New Method of Productivity Prediction in the Multilayer Commingled Production with Medium-High Water-Cut Period

产能预测是油田开发过程中一项十分重要的基础研究。然而,为兼顾油田的开发成本与开采效果,海上油田一般采用多层合注合采的开发模式,导致多层开采下产能预测十分困难,特别是中高含水期逐步暴露出层间、层内和平面的三大矛盾后的产能预测。以地质、油藏、测井、钻完井等多专业相融合为突破口,采用"单因素解析多因素耦合"的研究思路,系统总结了中高含水期产能预测的主控因素:宏观上,受沉积环境、成岩作用和成藏过程中的差异充注等地质因素控制;微观上,受油水渗流、流场分布和压力变化等开发因素影响;同时,产能与工程因素的完井方式相关。通过建立由多元主控因素定量耦合的产能预测模型,形成了一套系统的海上多层砂岩油藏定向井中高含水期产能预测新方法,并通过目标油田实际投产井的验证,表明新的预测方法准确度较高,精度达到89%。

Productivity prediction is an important basic research in reservoir engineering.Because of both production cost and production effect,multilayer commingled production generally used in offshore oilfield leads to difficulty in productivity prediction especially the prediction after water breakthrough.This paper,starting from the multi-disciplinary research of geology engineering,reservoir engineering,well logging,drilling and completion engineering,employs the single factor analysis and multi-factor coupling as research thinking technique and then,summarizes the main control forecast in medium high water-cut stage of production factors.Macroscopically,the productivity is affected by geological factors such as sedimentary environment,diagenesis and differential oil charge in oil-trapping process,while microscopically,the productivity is influenced by development factors such as oil water two-phase flow,flow field change and pressure distribution.At the same time,productivity is in correlation with completion method.Finally,a system of productivity prediction method about directional well in offshore multiple-sand reservoir at medium-high water-cut stage is formed by establishing aproductivity prediction model quantatively coupled bymultiple controlling factors.The actual operation of this method in the target well production shows that the new evaluation method is highly accurate,with the prediction accuracy up to 89%.