Sea bed logging applications: ANOVA analysis for synthetic data from electromagnetic (EM) simulator

Abstract

The aim of this research is to determine the significance level of parameters such as sediment thickness, frequency and step size for data generated from electromagnetic (EM) simulator for sea bed logging application that have been processed using cubic spline interpolation using ANOVA method. In this work synthetics data are generated from in house built simulator that is able to replicate sea bed logging environment. Sea bed logging (SBL) is a technique of finding resistive layers under sea bed by transmitting low frequency EM waves through sea water and sediment. Hydrocarbon is known to have high resistivity, about 30 - 500 Ωm and EM wave will be guided and reflected if there is hydrocarbon reservoir in the sediment. In SBL low frequency is used to obtain greater wavelength for longer wave penetration. In this work frequency used are 0.5Hz, 0.25Hz, 0.125Hz and 0.0625Hz and sediment thickness are varied from 1000m to 3000m incremented every 250m. Data collected are interpolated using cubic spline with step sizes of 4,8,12 and 16 and mean square are calculated between original and interpolated data. The Analysis of variance (ANOVA) method is used to study any significant different between sediment thickness level and spline step size levelat each frequency and sediment thickness level with frequency level at each step size. It is found from ANOVA tables that sediment thickness and step sizes and sediment thickness and frequency are having significant different. These indicate that the chosen parameters are contributing significantly to the MSE calculated.