地球物理学进展 ›› 2019, Vol. 34 ›› Issue (1): 119-124.doi: 10.6038/pg2019BB0598

• 应用地球物理学Ⅰ(油气及金属矿产地球物理勘探) • 上一篇    下一篇

基于溴化镧探测器的负源距密度测井研究

李鹏举1,2,付勇路1,宋延杰1,2,张云峰1,2,韩文胜1,张维3   

  1. 1. 东北石油大学,地球科学学院,黑龙江大庆 163318
    2. 东北石油大学,非常规油气成藏与开发省部共建国家重点实验室培育基地,黑龙江大庆 163318
    3. 大庆油田第五采油厂,黑龙江大庆 163513
  • 收稿日期:2018-04-28 修回日期:2018-11-04 出版日期:2019-02-20 发布日期:2019-04-15
  • 作者简介:李鹏举,男,1970年生,教授,博士,主要从事地球物理资料处理解释教学和研究工作.(E-mail: 13936900420@126.com)
  • 基金资助:
    国家自然科学基金项目“骨架导电低阻油层人造岩样实验及导电规律与导电模型研究”(41274110);“致密砂岩储层纳微米孔隙有效下限研究”(41572132);黑龙江省自然科学基金项目“致密砂岩导电规律与导电模型实验研究”联合资助.(D2015012)

Study on negative source spacing density logging dased on LaBr3(Ce) detector

LI Peng-ju1,2,FU Yong-lu1,SONG Yan-jie1,2,ZHANG Yun-feng1,2,HAN Wen-sheng1,ZHANG Wei3   

  1. 1. Earth Science Institute, Northeast Petroleum University, Heilongjiang Daqing 163318, China
    2. Accumulation and Development of Unconventional Oil and Gas, State Key Laboratory Cultivation Base Jointly-constructed by Heilongjiang Province and the Ministry of Science and Technology, Northeast Petroleum University, Heilongjiang Daqing 163318, China
    3. The Fifth Oil Extraction Plant of Daqing Oilfiled Company Limited, Heilongjiang Daqing 163513, China
  • Received:2018-04-28 Revised:2018-11-04 Online:2019-02-20 Published:2019-04-15

摘要:

为弥补传统双源距密度测井仪器纵向分辨率低、受井眼影响大的缺陷以及碘化钠(NaI(Tl))探测器的不足,提高密度测井识别油气层的能力,我们采用MCNP5蒙特卡罗模拟程序模拟研究了密度测井在负源距下增加溴化镧(LaBr3(Ce))探测器.首先对比研究了LaBr3(Ce)探测器与NaI(Tl)探测器的探测效率、能谱和响应特征;然后模拟计算LaBr3(Ce)探测器源距与光子通量的关系、负源距光子通量能谱、负源距探测深度与源距的关系、气层负源距光子通量与密度的关系.结果表明:LaBr3(Ce)探测器在密度测井中比NaI(Tl)探测器探测效率高、能峰高、峰总比大;负源距探测器与传统长、短源距探测器的响应规律近似相反;负源距探测器源距小,纵向分辨率高;探测深度浅,主要反映泥饼的性质,从而为泥饼校正提供丰富数据.因此,在双源距密度测井负源距区增加LaBr3(Ce)探测器可以提高地层密度的灵敏度、测量精度、纵向分辨率和改善泥饼及薄层校正效果,为有效勘探开发油气藏提供测井技术支持.

关键词: 密度测井, 蒙特卡罗模拟, LaBr3(Ce)探测器, 负源距, 探测深度, 纵向分辨率

Abstract:

To make up for the defects of dual detector density logging instrument,such as low vertical resolution,large borehole influence and the shortcomings of NaI(Tl) detectors and to improve the ability of identifying gas reservoirs,a study of adding LaBr3(Ce) detector in negative spacing range is done with MCNP5 Monte Carlo numerical simulation program. The study begins with detection efficiency of LaBr3(Ce) detector,energy spectra and response characteristics compared with NaI(Tl) detector. Then the relationship between spacing and photon flux,spectra in negative spacing,the relationship between radial investigation depth and negative spacing range,the relationship between flux and density in negative spacing are simulated. As a result of this study,LaBr3(Ce) detector has higher efficiency,higher peak and bigger peak to total ratio than NaI(Tl) detector. Compared with traditional long and short source spacing detectors,negative spacing detector has approximately opposite response characteristics. Negative spacing detector has shorter spacing,higher vertical resolution,shallower radial investigation depth,larger effect from mud cake and it can supply abundant data for mud cake correction. Therefore,it’s feasible to add LaBr3(Ce) detector in negative spacing range which can improve sensitivity,measurement accuracy,vertical resolution and the correction of mud cake and thin layer,providing technical supports for effective exploration and development of natural gas reservoirs.

Key words: Density logging, Monte Carlo simulation, LaBr3(Ce) detector, Negative spacing range, Investigation depth, Vertical resolution

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