The Application of Acoustic Full Waveform Logging in Petroleum Engineering

Abstract This article briefly introduces the application and processing of acoustic full waveform data and dipole shear imager (DSI) data The emphasis is on the applications of compressional waves, shear waves and Stoneley waves in the calculation of mechanical parameters of rock. The actual results is given through the analysis of in-situ applications. FOREWORD Presented to the petroleum industry in the 1950s', acoustic logging is chiefly used to provide the slowness of compressional waves and to calculate the formation porosity according to the Wyllie time average equation. With the development of petroleum industry, the calculation of many parameters, especially those of rock mechanics and the study of the formation stress depends on shear waves. Hence, the acquisition of shear wave data is a common concern of petroleum engineering. In the late 1970s', Schlumberger first introduced the long spacing acoustic full waveform logging device, which could be used to obtain the shear wave(S wave) data, thus making it possible to calculate many parameters especially the mechanical parameter of rock. However, in soft formation where shear wave velocity is less than that of compressional wave of the fluid in the borehole, the acoustic full waveform system cannot record the shear wave data. Then, Schlumberger introduced the dipole shear imager(DSI) in the 1990s', which improved the availability of shear wave data and extended the application of shear waves. Since the 1980s', long spacing acoustic logging and DSI have been used successively in Shengli oilfield. Achievements have been made in the application of acoustic full waveform logging. Nevertheless, the lack of shear wave logging in old wells and in most new wells restricts the study of many problems concerning petroleum industry and the calculation of reservoir parameters. To solve the problem, we have developed a technique for estimation of shear wave velocities. In comparison with DSI data, the results prove to be reasonably applicable. Thus, it is possible to use shear waves on a larger scale and solve many problems concerning petroleum engineering and geology. P. 323