摘要
研究各种地层和井眼环境因素对碳氧比C O测井长、短源距探测器的影响规律,可以为C O测井仪器的刻度方法提供指导,为解释模型的建立和数据处理提供依据.本文用MonteCarlo方法,计算了C O值随井眼直径、水泥环厚度、套管直径、孔隙度、含油饱和度、地层岩性和油密度的变化规律.从中看出,当井内流体为油时,井径或套管直径增大,C O值增大,井眼影响增大;当井内流体为水时,井径或套管直径的增大,C O值减小;水泥环厚度增加时C O值减小;当井眼条件不变时,地层孔隙度越大,含油饱和度越大,C O值越大,对测井越有利;反之,地层孔隙度越小,含油饱和度越小,C O值越小,对测井不利;地层岩性对C O值的影响显著,相同条件下,碳酸盐岩比砂岩的C O值高;油密度越大,C O值越大.
It helps to design scale schemes and interpretation model to study the influence of borehole and formation environments in C/O logging on two detectors. The paper investigates the rules of C/O values changing with borehole diameter, cement thickness, case size, formation porosity , oil saturation, formation lithology and oil density. The results indicate that when a borehole is full of oil, C/O values increase with increasing borehole diameter or case size, and the influence of borehole increases. When a borehole is full of water, C/O values decrease with increasing borehole diameter or case size. C/O values decrease with increasing cement thickness. The higher porosity and water saturation, the higher C/O values when borehole condition is invariable, which is useful for C/O logging. Contrarily, the less porosity and water saturation, the less C/O values, and which is bad for C/O logging. Formation lithology influences seriously C/O values, limestone has higher C/O value than that of sand when other conditions are the same. The higher oil density, the higher C/O value. The paper also introduces a data-processing method that can remove the influence of borehole and formation environment on the two detectors.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第2期459-464,共6页
Chinese Journal of Geophysics
基金
中国海洋石油总公司重点研究项目"脉冲中子寿命和碳氧比能谱测井研制"资助
