Measurement of sound velocity in oil wells based on fast adaptive median filtering

Abstract

Measurement of sound velocity in oil wells has long been a challenging industrial issue due to the difficultyin obtaining clear oil pipe coupling waves in strong noise. In this paper, a novel sound velocity measurement methodis developed for the dynamic liquid level of oil wells based on fast adaptive median filtering. First, to solve the noiseinterference problem in the reflected oil pipe coupling wave, a fast adaptive median filtering algorithm is proposed toobtain an accurate oil pipe coupling wave. Then a curve fitting method based on range discrete coefficient is developedto estimate the sound velocity in the tubing-casing annular space of oil wells. The fitting sound velocity can reflect thepropagation rule of the real sound velocity. In particular, the sound velocity at any position within the tubing-casingannular space can be accurately calculated by the fitting function. Finally, the proposed method is applied to thedynamic liquid level of an oil well. Experimental results show the effectiveness and favorable accuracy in estimating thesound velocity distribution.