超声成像测井换能器的实验研究  

Experimental study on ultrasonic imaging logging transducer

作　　者：卢俊强[1,2] 吴金平 车小花 门百永[1,2] 韩继勇 LU JunQiang;WU JinPing;CHE XiaoHua;MEN BaiYong;HAN JiYong(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Key Laboratory of Earth Prospecting and Information Technology,Beijing 102249,China;SINOPEC Engineering Technology Research Institute,Beijing 102200,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]北京市地球探测与信息技术重点实验室,北京102249 [3]中石化石油工程技术研究院有限公司,北京102200

出　　处：《地球物理学进展》2023年第2期832-838,共7页Progress in Geophysics

基　　金：国家自然科学基金(42174218,41874210)资助。

摘　　要：随钻超声成像测井通过钻铤的旋转实现周向扫描成像,为了提高随钻超声成像测井在周向成像测量的方位覆盖率,需要安装多个换能器同时进行测量,换能器的响应不一致则会产生错误的成像测量结果,本文通过实验测量的方法对随钻超声成像测井换能器的响应特性进行研究.实验测试系统主要由高精度定位控制系统、PXI采集系统、针形水听器、OLYMPUS 5077PR信号源、信号转换器、载物台、示波器等构成,是一个具有4自由度的小型声学定位测控系统.实验主要包括超声换能器的轴线声场测量以及指向性测量.对超声换能器的轴线声场进行测量,得到了换能器的远近场临界距离和幅度响应特性,实验表明换能器远近场临界距离在3.25 cm附近,各个换能器的幅度响应特性一致性较好.通过对换能器指向性进行测量,表明3 dB角宽大致在12°左右,换能器具有较好的聚焦特性.该研究提供一种评价超声成像测井换能器的有效方法,为仪器研制过程中的换能器匹配选择提供依据,可为超声成像测井仪器的研制提供有力支撑.LWD(Logging While Drilling) ultrasonic imaging requires circumferential scanning imaging through the rotation of the drill collar. In order to improve the azimuthal coverage of LWD ultrasonic imaging in the circumferential imaging measurement, multiple transducers need to be installed for measurement at the same time, and the inconsistent response of the transducers will produce wrong imaging measurement results. This paper studies the response characteristics of LWD ultrasonic imaging transducers through experimental measurement. The experimental test system is mainly composed of high-precision positioning control system, PXI acquisition system, needle hydrophone, Olympus 5077PR signal source, signal converter, objective table, oscilloscope, etc., and it is a small acoustic positioning and measurement system with 4 degrees of freedom. The experiment mainly includes the measurement of axial sound field and directivity of ultrasonic transducer. The axial sound field of the ultrasonic transducer is measured, and the far-near field critical distance and amplitude response characteristics of the transducer are obtained. The experiment shows that the far-near field critical distance of the transducer is about 3.25 cm, and the amplitude response characteristics of each transducer are consistent. The directivity of the transducer is measured, the result shows that the 3 dB angular width is about 12°, and the transducers have good focusing characteristics. This study provides an effective method to evaluate ultrasonic imaging logging transducers, which provides a basis for the matching selection of transducers in the process of tool development, and provides a strong support for the development of ultrasonic imaging logging tools.

关 键 词：超声成像测井 换能器 指向性 轴线声场 实验 

分 类 号：P631[天文地球—地质矿产勘探]