Hole-diameter enlargement correction improvements on GR curves recorded by Atlas logging tools
Xia Zhu1, Zhao Lei2, Li Kai1, Wang Zhibao2, Zhang Sheng1, Zhao Shiquan1
1. Reservoir Geophysics Center, BGP Inc., CNPC, Zhuozhou, Hebei 072751, China;
2. Research Institute of Exploration and Development, Zhongyuan Oilfield Branch Co., SINOPEC, Puyang, Henan 457001, China
Abstract:Well collapses occur most likely in terrestrial facies sands and shale formations due to borehole instability. The variation of irregular hole diameters usually distort measured Gamma curve values. Therefore,we need to correct primary Gamma curves with caliper correction methods. However,in the secondary logging data processing and interpretation,there are some difficulties such as multi-parameter calculations,applicability limit,and unsatisfactory correction when using Atlas caliper correction module. Based on conventional methods analysis,numerical simulation,crossplot analysis,normalization,and multi-parameter calculation,we establish the relationship between Gamma logging curves and hole enlargement ratio,discuss influence of variable drill bits,diameter enlargement,and slop parameter on different curves and corrections. Then we obtain improved correction formulas of Gamma curves,which are easier,faster and more efficient. Finally,we obtain a correction chart for the whole area. Research results show that the reliability,availability and rationality of lithological identification and reservoir interpretation are obviously improved on GR curves corrected by the proposed method in an oil field.
Yong Shihe. A study on the methods and programs for logging data preprocessing. Journal of East China Petroleum Institute,1984(1):30-41.
[2]
田志杰. 测井资料环境校正、标准化处理程序设计与实现. 北京:中国地质大学(北京),2006.
Tian Zhijie. Programming and Implementation of the Logging Data Environmental Correction and Standard Processing. China University of Geosciences(Beijing),Beijing,2006.
[3]
王智. 测井资料环境校正技术研究及应用[学位论文]. 四川成都:西南石油大学,2006.
Wang Zhi. A Study and Application on the Technology of the Logging Data Environmental Correction[D]. Southwest Petroleum University,Chengdu,Sichuan,2006.
[4]
姜艳玲. 常规测井资料井眼环境校正软件开发. 石油工业计算机应用,2010,(2):39-40.
Jiang Yanling. Software development of borehole environment correction with conventional well logging data. Computer Application of Petroleum,2010,(2):39-40.
Yang Huaijie.Study method on computing reservoir parameters using well log data in Dongying group of A region[D]. China University of Geosciences(Wuhan),Wuhan,Hubei,2013.
Xu Bo,Wang Zhonghao,Li Zegang et al. Auto-correction method of environmental effect on Gamma logging data of logging while drilling. Journal of Oil and Gas Technology,2009,31(5):82-85.
Wang Bin,Fan Xiaomin. Application of numerical simulation in the rocks influence the Gamma-ray logging. Journal of Jilin University(Earth Science Edition),2006,36(S2):166-168.
Shang Qinglong. 3D Simulation of Well Logging Responses and Techniques of the Data Synthesis and Enhancement of Vertical Resolution for New Type of GR Tool[D]. Jilin University,Changchun,Jilin,2013.
[9]
陶果. 一种实用的自然伽马测井环境校正方法. 测井技术,1987,11(3):54-58.
Tao Guo. A practical technology for GR logging correction method. Well Logging Technology,1987,11(3):54-58.
Jin Youchun,Xing Fengrong,Wang Yanli et al. Method for depth corrections of isotope injection pro-file logs. Well Logging Technology, 2002, 26(2):165-167.
Sun Zhongchun,Gu Zhengang,Li Jun et al. Correction of well logs in the case of severe borehole enlargement. Xinjiang Petroleum Geology,2006,27(5):559-561.
Liu Zhidi,Wang Jian,Yang Xiuchun et al. Analyzing on applicability of expanding influence correction method of density logging in the coalbed methane reservoir. Progress in Geophysics,2014,29(5):2219-2223.