摘要
为提高随钻密度测量的准确度,利用蒙特卡罗方法对随钻密度测井仪的环境影响进行了模拟。补偿密度随钻测井仪的短、长源距的探测深度分别为6cm和13.5cm,伽马空间分布表明仪器的屏蔽效果较好,仪器钻遇地层界面时,随着源窗的正面与地层界面和与地层界面法线的夹角α或β增大,短、长源距的计数率都分别呈现过渡越快和缓慢的趋势。大斜度井水平井情况下仪器处于偏心并旋转状态,泥浆间隙小于1cm时仪器基本满足测量精度要求。该密度仪器主要用于6in井眼,泥浆间隙在0~6.4mm之间。补偿密度校正可以保证仪器的测量误差在允许范围内。若要保证仪器在井眼形变、垮塌处测量精度,有必要用超声井径对密度仪器进行分区补偿。
To improve the accuracy of measurements,the Monte Carlo method was used to simulate the LWD density logging environmental impact.The results show that the DOI of near and far detectors are 6cm and 13.5cm respectively.Gamma ray space distribution indicates that the shielding effect is better in the working state.Drilling at the bed interface,the transitions of both near and far count rates become more fast and slowly as theαorβangle increases in HA/HZ wells.The tool is in an eccentric rotating state when the standoff less than 1cm,the accuracy of the tool meets the requirements.However,the tool is mainly used for 6in borehole,and the mud standoff is between 0~6.4mm.Compensation density correction ensures measurement errors in the allowable range.To ensure accuracy in the borehole deformation or collapse,it is necessary to use ultrasonic caliper tools to do a zonal compensation.
出处
《测井技术》
CAS
CSCD
2015年第5期607-610,共4页
Well Logging Technology
基金
中国石油集团测井有限公司科学研究与技术开发项目(CPL2012-A08)
