Rate-Convolved Horner Plot for Analysis of Simultaneously Acquired Flow Rate and Pressure Data

Abstract

ABSTRACT During the last five years, the use of simultaneously acquired pressure and flow rate data in well test analysis has become quite common. The additional measurement of downhole flow rate makes the assumption of constant wellbore storage unnecessary and enables one to perform a more rigorous analysis. Many techniques have evolved for analyzing such data. These include convolution, deconvolution, convolution derivative, and convolution type-curves. In this paper, we present a new technique called the Rate-Convolved Horner plot for analyzing rate and pressure data which offers certain advantages in comparison to other methods. These advantages include: simplicity and analogy to conventional Horner plot, integration of flow period data with shut-in data, better handle on skin, and its adaptability for quick well-site interpretation. Field examples are presented to show the application of this technique to a variety of well testing configurations. The technique presented in this paper is especially suited for the analysis of short duration transient tests, i.e., after underbalance perforating, TCP/DST, closed chamber testing and IMPULSE* Testing because of rapid variations of flow rate in such tests.