随钻可控源中子测井仪器研究

Study on Neutron Logging While Drilling Tool Controllable Neutron Source

斯伦贝谢公司的随钻可控源测井仪器已投入商业化应用,为缩短国内外差距,中国石油集团测井有限公司研制了适用于随钻测井的可控源中子孔隙度仪器,并在油田进行了随钻测井。通过国内外发展现状对比,介绍了随钻可控源脉冲中子测井仪器研究思路。利用可控源向地层发射中子,尽可能多地采集有关的地层信息,将理论模拟、试验验证及实际应用相结合,指导仪器探测器、探测器位置、中子发生器及中子管等的设计。研究将孔隙度及地层宏观俘获截面两种参数的测量集成在一根钻铤上,实现一次下井完成两种参数测量,识别含气层、含水饱和度等,可以节省测井时间和成本。

The logging while drilling tool with controllable neutron source has been available commercially abroad. To shorten the gap from abroad, the neutron LWD tool with controllable neutron for porosity logging is developed, and it has been successfully introduced and applied in some oilfields domestically. Based on the proceedings of the technique at home and abroad, the research logic of the self developed tool is illustrated. The controllable sources are used to emit neutrons towards the formation and to acquire the relative formation information. The design works on detector structure, detector position, neutron generator and neutron tube are instructed and optimized through the combination of theoretical modeling, experimental verification and practical applications. The acquisition of poros- ity and macroscopic capture cross section are carried out through integrating them into one collar. The two parameters can be measured in one logging trip, and gas-bearing layer and water saturation can be identified. Therefore, the technique can save time and cost of logging.