摘要
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。
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.
引文
[1] 岳爱忠.阵列中子测井方法研究 [D].长春:吉林大学,2000.
[2] 丁次乾.矿场地球物理 [M].东营:中国石油大学出版社,2006.
[3] 范红卫.阵列中子测井方法研究 [J].江汉石油学院学报,2003,26(增刊):42-43.
[4] 郑世平,秦爱玲,赵舒平.测井中子发生器 [J].地球物理学进展,2009,24(4):1521-1526.
[5] 吕俊涛.脉冲中子发生器高压控制系统的自动控制设计 [J].同位素,2008,21(3):155-160.
[6] 鲁保平,岳爱忠,何绪新,等.多探测器中子测井仪探测器阵列:200520016124.5 [P].2006-07-05.
[7] 张建民,邓力,谢仲生,等.脉冲阵列中子测井探测器效率的研究 [J].核技术,2001,24(8):680-685.
[8] KNOLL G F.Radiation detection and measurement [M].New York:Wiley,2010.
[9] 丁大钊,叶春堂,赵志祥.中子物理学 [M].北京:原子能出版社,2001.
[10] 第宇鸣,方国明,邱晓林,等.核辐射堆积脉冲数字化判别 [J].原子能科学技术,2008,42(4):370-372.
*非法定计量单位,1 in=2.54 cm,下同