充氮气钻井井筒气液两相流流量设计图版与应用实例

Application on Drilling Fluid Parameters' Chart Design of Aerated Underbalanced Drilling in Fracture Tight Reservoir

充气钻井是发现和保护致密油气藏、防止裂缝性储层漏失、提高机械钻速的重要技术手段。通过实验资料和计算论证,阐述了充氮气钻井井筒环空与钻柱内两相流体呈现出的多种流型特征;并建立了充氮气钻井井筒气液两相流稳态流动的数学模型。通过数值解法的计算,绘制出常用井身结构中φ216 mm井眼实施充氮气钻井时井筒气液流体注入流量的设计图版,可供钻井施工和工程设计。对于准噶尔盆地百泉1井裂缝性致密储层的充氮气钻井现场试验,充分证实新建的钻井气液两相流参数设计图版完全满足充氮气钻井设计和施工要求;且充氮气钻井具有地层适应性强、压力控制范围大、专用设备需求量小、钻井流程简单的特点。

Aerated drilling is an important technical method for exploring and protecting oil ＆amp; gas reservoir, controlling mud loss in reservoir with natural fractures, and improving the rate of penetration.Fluid patterns of gas-liquid two-phase flow in annulus and drillstring while drilling was expounded, which is derived from many experimental data and computing research.Meanwhile, aerated drilling fluid wellhole flow mechanics model and numerical solution were established.And the gas-liquid flow rate design charts for φ216 mm wellhole in conventional well structure were calculated and plotted, which have contributed to field operation and engineering design.The flied aerated nitrogen drilling experiment in Baiquan-1 well′s fracture tight reservoir have completely confirmed that the new the gas-liquid flow rate design charts have been satisfied for nitrogen aerated underbalanced drilling engineering design and flied operation, and the drilling technology have many characteristics including stronger formation adaptability, larger pressure control range, smaller scare of special equipment, simper drilling process.