Joint frequency expanding method of crosswell seismic data and 3D seismic data

Abstract

Crosswell seismic data and 3D seismic data are seismic response of different frequency band from the same geologic target. Crosswell seismic data possesses very high resolution in comparing with 3D seismic data for its higher main frequency and broader frequency band. However crosswell seismic data only exist between source well and receiver well, while 3D seismic data has excellent spatial distribution. It is possible to integrate different types of data and get more reliable underground information (Lines et al., 1988; Hu et al.,2007; Heinche et al., 2006). Here we put forward joint frequency expanding (JFE) method of crosswell seismic data and 3D seismic data. We expand 3D seismic data frequency band according to crosswell seismic data, and improve the resolution ability of 3D seismic data. First we use 3D seismic data and crosswell data to build 3D seismic reflect coefficient model, which possesses high resolution, and is consistent with 3D seismic data in structure. Second we use this reflect coefficient model as constraining condition, and joint inversion algorithm is used to get inverted reflect coefficients from 3D seismic data. Finally according to time‐frequency analysis of 3D seismic data, we choose an appropriate high resolution wavelet to convolve with the inverted reflect coefficients, and produces high resolution 3D seismic data. Here we design a processing flow and applied it to Ken 71 data of ShengLi oil field. With the help of crosswell seismic data, 3D seismic data resolution is improved, main frequency is increased from 35Hz to 75Hz, and frequency band is also widened by 30Hz.