庆深气田致密砂砾岩气藏小井眼水平井钻井技术

为提高大庆油田深层致密砂砾岩气藏的勘探开发效益,缩短钻井周期,降低钻井成本,开展了小井眼水平井钻井技术研究。首先,按照套管允许的弯曲半径必须小于井眼实际弯曲半径的原则,在分析φ215.9 mm弯曲井眼安全下入φ177.8 mm技术套管和φ152.4 mm钻具组合通过φ177.8 mm技术套管能力的基础上,对井身结构进行了优化;其次,考虑到目的层可能提前或滞后的情况,利用探气顶稳斜角公式计算了不同厚度储层的稳斜角,同时考虑造斜井眼尺寸以及实际地层造斜能力,对井眼轨道进行了优化;最后,根据钻遇地层的特点,对钻头进行了选型,设计了钻具组合,优选了钻井参数,最终形成了庆深气田致密砂砾岩气藏小井眼水平井钻井技术。该技术在徐深平3X井成功实施,钻井周期与常规水平井相比缩短了32.83%。这表明,该技术可为深层砂砾岩气藏的勘探开发提供新的技术手段。 

Horizontal Slim-Hole Drilling Technology for Deep Tight Glutenite Gas Reservoir in Qingshen Gas Field

: In order to improve the prospecting benefit,shorten drilling cycle and save drilling cost in deep tight glutinite gas reservoirs in Daqing Oilfield,the research on horizontal slim-hole drilling had been carried out.Firstly,according to the principle that allowable casing bent radius must be less than the actual bent radius of wellbore,and the casing program was optimized on the basis of analyzing the possibility that running φ177.8 mm intermediate casing in φ215.9 mm curved wellbore safely,and the φ152.4 mm BHA passed through φ177.8 mm intermediate casing.Secondly,as the depth of target pay zone may be shallower or deeper than that of prediction,hold angle formula was used to calculate the hold angle of reservoirs in different thickness,in addition,taking the formation deflecting ability and borehole size into account in build up section,the well trajectory was optimized.Finally,according to the features of formations,the type of drill bit,bottom-hole assembly and drilling parameters were optimized,the horizontal slim-hole drilling technology had been formed for deep tight glutenite gas reservoirs in Qingshen Gas Field.The application of this technology in Well Xushenping 3X led to a reduction of drilling cycle time of 32.83% than conventional horizontal well method,it provides new technical means for exploration and development in deep tight glutenite gas reservoirs.