Experimental Study On Three Dimensional Receiving Directivity Of Phased Arc Array Used In Acoustic Logging

With the intensified exploration and de velopment of complex oil and gas reservoirs,the demand for azimuth acoustic logging technology and three-dimensional acoustic logging technology is increasingly urgent.The directional radiating and directional receiving technology of downhole acoustic waves can solve a series of acoustic logging problems.And the directional receiving technology uses a phased array acoustic wave receiver.Exploring the three-dimensional receiving directivity characteristics of the phased array acoustic wave receiver is important to realize the directional receiving technology and further improve the quality of sonic logging.In this paper,the receiving directivity of the phased array acoustic wave receiver were studied systematically by experiment.Firstly,the working principle of the acoustic logging receiving transducer was introduced,the phased array receiving method and the phased array receiving directivity measurement method were introduced in detail.Secondly,the phased array receiving directivity measurement system was introduced,including the experiment equipment and instructions,the spatial layout of transducers,the introduction of the high-precision positioning system and the calibrating operation.The consistency of the phased array receiving transducer was e valuated from two aspects: impedance characteristics and receiving directivity characteristics.Finally,the phased array circular array receiving directivity was measured by experiment,The experimental data was processed and analyzed.The results show that both a single array element and different sub-arrays have directional characteristics.As the number increasing,the directivity is enhanced,and the dominant receiving direction can be adjusted accurately by setting the delay time;the three-dimensional receiving directivity chart clearly shows its horizontal and vertical directional characteristics.The experiment data and research results provide a certain reference for the realization of directional receiving and improving the quality of acoustic logging.