高性能井筒超声脉冲回波扫描成像测井仪研制

Development of a high-performance wellbore ultrasonic scanning imaging logging tool based on pulse-echo

多功能超声成像测井仪采用超声脉冲反射法对套管腐蚀及固井质量做定量评价。利用从井眼内壁反射波形提取的幅度及到时实现井眼内壁高分辨率成像;提取套管共振波的共振频率计算套管厚度;采用全波反演方法反演套管后环空介质的声阻抗。通过优化采集模式、研制高性能换能器并建立固井质量评价模版确保仪器性能优于同类产品。现场实测资料表明,仪器可准确测量套管壁厚,识别射孔层段和射孔孔眼,识别套损缺陷,为套管找漏及侧钻点选择提供重要的决策依据,并准确评价双层套管情况下的内层套管固井质量,同时还可以在裸眼井中获取井壁表面裂缝、层理、孔洞等地质构造信息。

Multi-functional ultrasonic imaging logging tool can quantitatively evaluate casing corrosion and cementing job quality by ultrasonic pulse-echo method.High resolution imaging of the wellbore inner wall can be achieved by utilizing the amplitude and arrival time of the reflected waveform.The resonance frequency of the resonant wave in the casing is analyzed to calculate the thickness of the casing,and the full wave inversion method is deployed to invert the acoustic impedance of the medium behind the casing.Proper designed acquisition mode,high-performance transducer and cement bond evaluation model insure the tool a better quality compared with competitors.Field measurement data shows that the instrument can accurately measure the casing thickness and detect the casing defects due to corrosion and erosion or perforation holes to provide guideline for determination of casing leakage points and sidedrill points,meanwhile it can also evaluate the cement bonding quality which is of great significance for the assessment of wellbore integrity.The instrument can also be deployed in open hole to gain geological features such as fracture,cavity and formation homogeneity.