阵列中子孔隙度测井仪研究

采用可控脉冲中子源(脉冲中子发生器)代替传统化学源,实现了测井过程零放射性污染;采用多组超热中子及热中子探测器。结合岩性校正、仪器与井壁间隙校正、套后井套管水泥环校正以及放射源强度校正等孔隙度校正算法,实现套前、套后模式高精度测井。从阵列中子孔隙度测井仪现场试验井中选取了1口有代表性的测井资料,通过分析重复性、一致性和纵向分辨率证实阵列中子孔隙度测井曲线能准确地反映地层孔隙度。

Development of Array Neutron Porosity Logging Tool

The controllable pulsed neutron source(pulse neutron generator)instead of traditional chemical source was used in this tool,which realized zero radioactive pollution during logging.Moreover,many sets of ultra-thermal neutrons and thermal neutron detectors were also used in this tool.Combining the porosity correction algorithms such as lithology correction,clearance correction between tool and well wall,casing and cement correction of cased well,and radiation source strength correction,the high precision logging for open hole well and cased well was realized.Logging data of a representative well from the wells which using array neutron porosity logging tool was selected for testing,and it was found that the repeatability,consistency and longitudinal resolution of the data was great,which mean the array neutron porosity logging curve can accurately reflect the porosity information of formation.