Errors Introduced by Multiphase Flow Correlations on Production Analysis

摘要

First and foremost, production analysis techniques requirernaccurate rate and bottomhole pressure histories. In most casesrnthe pressure history of the well is not measured directly at thernbottomhole condition, but is calculated from surfacernmeasurements by the use of single or multiphase flowrncorrelations. In some cases significant error is introducedrnthrough the use of these correlations.rnThis paper evaluates the magnitude of such errors for oil andrngas producers with regard to the estimation of flow capacity,rncompletion efficiency, and effective drainage area. Syntheticrncases are used as control sets in order to evaluate thernsensitivity of the results to the various multiphase flowrncorrelations and flowing conditions. In addition to syntheticrn(simulated) performance behavior, field cases are presentedrnand the variance in estimated reservoir and completionrnproperties is evaluated.rnThe technical contributions of this paper are:rna. Systematic evaluation of the effect of errors in flowrnrates and bottomhole flowing pressures on productionrndata analysis — using both synthetic and field derivedrnwell performance data.rnB. Qualitative guidelines as the effect of errors in rate andrnpressure on estimated reservoir properties.rnC. Establishment of the most relevant pressure droprncorrelations for use in practice.