Acoustic time–frequency characteristics of igneous reservoir with diferent fuid properties

The identification of formation fluid properties of igneous rock reservoirs plays a vital role in the igneous rock oil/gas exploration and development. Due to the complex lithology, low porosity, low permeability and strong heterogeneity of igneous rock reservoirs, conventional geophysical logging evaluation methods are not as accurate as sandstone reservoirs in response to different fluid properties of igneous rock reservoirs. It is difficult to identify the fluid type of the formation. In order to solve this problem, with the rapid development of array acoustic logging technology, this paper proposes a new method for analyzing the time–frequency characteristics of full wave train data based on the large amount of information contained in the array acoustic wave train, hoping to more accurately identify the fluid properties of igneous rock reservoirs. This paper introduces the time slice and frequency slice of Choi–Williams distribution with different IMF components obtained by EMD method and analyzes the characteristics of time slice and frequency slice of reservoirs with different fluid properties, in order to be used for identification of formation fluid types. The results show that the time slices and frequency slices of different IMF components have significantly different characteristics for different formation fluid properties of igneous rocks. This new method can provide geophysical and geological researchers with some new information to more accurately identify the properties of formation fluids.