低渗裂缝性储层注水井钻关泄压模拟

针对注水后低渗裂缝性储层地层压力和注水井泄压时间难以确定,影响调整井安全钻井的问题。结合低渗裂缝储层渗流特点,运用变形双重介质渗流理论,建立泄压后储层动态地层压力模型。利用数值模拟技术,预测关井泄压和溢流泄压方式下泄压区地层压力分布随泄压时间变化规律。应用预测泄压过程中泄压区地层压力分布变化规律得出不同泄压方式注水井的钻关时间,制定注水井的钻关方案。研究表明,泄压区内裂缝连通低压处起提高泄压效率的作用;关井和溢流泄压过程,注水井井底压力不应作为衡量待钻点处地层压力的指标;应用对泄压区地层压力预测指导注水井进行钻关,满足安全调整井钻井实际应用。

Time Prediction of Injection Well Decompression in low Permeability Fractured Reservoir

It is very difficult to determine formation pressure and water injection well decompression time of low permeability reservoir after water injection, which can affect safe well drilling. Combined with seepage characteristics of the low permeability fractured reservoir, based on deformable double media seepage theory, considering rock and fracture pressure sensitive effect, dynamic model of reservoir formation pressure after pressure relief was established. Numerical simulation technology was used to predict the change of formation pressure distribution with the decompression time under shutting pressure relief and overflow pressure relief. Well drilling and shutting time of water injection well under different pressure relief mode was determined, so well drilling and shutting time scheme was made. Research shows that cracks connection of low pressure area in the pressure relief zone can improve pressure relief efficiency; in shut-in and overflow pressure relief processes, injection well bottom pressure should not be as a index of drill point formation pressure; The prediction of formation pressure in the pressure relief zone can be used to guide the drilling and shutting of the water injection well, which can satisfy the practical application of the safe adjustment of well drilling.