元素与自然伽马能谱录井技术在四川盆地威远区块的应用——以B1井为例

Application of element and natural gamma-ray spectral logging in Weiyuan Area of Sichuan Basin:A case study of Well B1

目前四川盆地威远区块页岩气迈入了规模开发新阶段,但气体钻井、PDC钻头+旋转导向等钻井工艺却使得岩屑呈细碎、粉末状,依靠岩屑录井对地层岩性难以识别,增大了优质页岩取心卡层、小层精细划分的难度。为此,针对四川盆地威远区块下志留统龙马溪组页岩储层的特点,将元素与自然伽马能谱录井技术应用于页岩气开发中。现场应用效果表明,采用元素与自然伽马能谱录井技术,保障了优质页岩取心卡层的准确性,解决了页岩气小层精细划分的难题,为辅助水平井地质导向、保障页岩气储层钻遇率提供了有力的技术支持。

The development of shale gas in the Weiyuan area of Sichuan Basin has entered a new phase,but techniques such as gas drilling and PDC bit+rotary steering drilling,a mass of fine-grained or power-like cuttings are often generated,making it hard to iderntify the stratum lithology through cutting longing,and to coring,layer determination and sublayer dvision.In this study,the element and natural gamma-ray spectral logging was applied in the Lower Silurian Longmaxi shale gas reservoir in theWeiyuan area of Sichuan Basin.Field applications show that the element and natural gamma-ray spectral logging ensure the accuracy of determing coring horizon,and solve the problem of sublayer division.Therefore,this technique provide a powerful support for the horizontal well geo-steering drilling to penetrate more shale gas reservoirs.