摘要
扇区水泥胶结测井可测量分扇区声幅、定性指示沟槽,有效判别水泥环沟槽大小和分布。为了计算水泥环沟槽宽度,建立固结水泥套管井声场模型和声场波动方程,采用三维有限元数值模拟方法,考虑探头、套管、井眼、水泥环的实际尺寸和形状结构的影响,模拟不同水泥环沟槽宽度的声幅、声波变密度和八扇区水泥胶结测井的测井响应,分析水泥环沟槽宽度变化的水泥胶结测井响应规律,推导水泥环沟槽宽度与套管波衰减系数之间的线性关系式,使用水泥环扇区缺失不同角度的理论数据和不同胶结率刻度井数据,检验沟槽宽度计算方法。结果表明:声幅、声波变密度和八扇区水泥胶结测井套管波首波相对幅度随沟槽宽度增加而增大,套管波首波相对幅度对数平均值与沟槽宽度之间存在较好的线性关系;水泥环沟槽宽度计算方法正确且实用,八扇区水泥胶结测井计算的沟槽宽度精度最高,可定量评价环向宽度大于45°的水泥环沟槽,并准确识别纵向厚度大于0.4 m的水平层状未胶结层段。该结果为扇区声幅型水泥胶结测井沟槽宽度定量评价提供参考。
Sector cement bond logging can measure the amplitude of casing waves of the sector to qualitatively indicate the channel,and then effectively evaluate the size and distribution of channels of cement sheath.Aiming at the quantitative calculation of channel width of cement sheath for eight-sector bond tool,the acoustic field model and wave equation for cement-consolidated cased holes are established,and solved with three-dimensional finite element numerical method.Then,the responses of CBL,VDL and SBT are simulated and obtained for different channel width of cement sheath,and the actual physical dimensions and shape and structure of probes,casing,wellbore,and cement sheath are considered.The response law of cement bond logging with changes in the channel width of cement sheath is analyzed.Therefore,the linear relationship between the channel width of cement sheath and the attenuation factor of casing wave is derived,and the accuracy of channel width calculation is verified with theoretical simulation data for circumferential cement loss of different angles and calibration well data with different bond rates.The results show that the relative amplitudes of head wave of casing waves for CBL,VDL and SBT increase with channel width.The average of logarithmic of relative amplitudes of head wave of casing wave for SBT and the logarithmic of relative amplitudes of head wave of casing waves for CBL and VDL all have a good linear relationship with channel width.It is shown that the established method for calculating the channel width of cement sheath is correct and practical,and the accuracy of channel width of cement sheath calculated with SBT is highest.SBT can quantitatively evaluate channels of cement sheath with circumferential angles greater than 45°,and accurately identify horizontal unconsolidated layers with vertical thickness greater than 0.4 m.The result provides a reference for quantitative evaluation of channel width with the amplitudes of sector-receivers of SBT.
作者
王天
王滨涛
韩琳
樊玉秀
图亚
唐晓敏
宋延杰
WANG Tian;WANG Bintao;HAN Lin;FAN Yuxiu;TU Ya;TANG Xiaomin;SONG Yanjie(Daqing Branch of China National Logging Corporation,Daqing,Heilongjiang 163412,China;School of Earth Sciences,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;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,Daqing,Heilongjiang 163318,China)
出处
《东北石油大学学报》
CAS
北大核心
2023年第4期95-106,I0007,共13页
Journal of Northeast Petroleum University
基金
中国石油天然气集团有限公司科学研究与技术开发项目(2019D-3809)
黑龙江省自然科学基金项目(D2015012)。
关键词
八扇区水泥胶结测井
水泥环扇区缺失
有限元数值模拟
套管波衰减系数
水泥环沟槽宽度
eight-sector cement bond logging
circumferential cement loss
finite element numerical simulation
attenuation factor of casing wave
channel width of cement sheath
