A Deconvolution Technique Using Fast-Fourier Transforms - Texas A&M University (TAMU) Scholar

Abstract We present a deconvolution technique based on a fast-Fourier-transform algorithm. With the new technique, we can deconvolve "noisy" pressure drawdown and buildup test pressure-time data (distorted by wellbore storage) and "noisy" rate data. The wellbore storage coefficient can be variable in the general case. In cases with no rate measurements, we use a "blind" deconvolution method to restore the pressure response free of wellbore storage distortion. Our technique detects the afterflow/unloading rate function using Fourier analysis of the observed pressure data. The technique can unveil the early time behavior of a reservoir system masked by wellbore storage distortion and it thus provides a powerful tool to improve pressure transient test interpretation. It has the advantages of suppressing the noise in the measured data, handling the problem of variable wellbore storage, and deconvolving the pressure data without rate measurement. We demonstrate the applicability of the method with a variety of synthetic and actual field cases for both oil and gas wells. Some of the actual cases include measured rates (which we use only for reference purposes) and others do not.

A Deconvolution Technique Using Fast-Fourier Transforms Conference Paper