A Nodal Analysis Based Monitoring of an Electric Submersible Pump Operation in Multiphase Flow

Joseph Iranzi,Jihoon Wang,Youngsoo Lee,Hanam Son

doi:10.3390/app12062825

Abstract

Electrical submersible pump (ESP) operation is compromised by free gas, resulting in premature pump failure and production losses in new wells. It is essential to detect the onset of abnormal operations. We develop a model that predicts abnormal ESP operation when the free gas level increases in the pump. The model compares operation parameters with the parameters of normal operating ranges; it shuts down the ESP when necessary. We used a Schlumberger PIPESIM software (version 2017.01) to perform nodal analysis technique; we tested the model using the other multiphase correlation model and field case studies (where the gas problem in ESP was reported). We employ a homogenous model to calculate the differential pump pressures at various gas volume fractions. Nodal analysis of the intake and discharge point predicted the commencement of abnormal ESP conditions and the associated parameters (critical gas fraction, minimum operating pump intake pressure, and pump discharge pressure). The model results were similar to other surging correlation models (e.g., Romero, Dunbar, Turpin, Cirilo, and Zhou models); they were also identical to field case studies. We identify three performance stability phases when an ESP is exposed to free gas. These are the normal and abnormal operating ranges, as well as the ESP shutdown condition. Modeling permits careful monitoring of ESP operations that can be compromised by free gas.

Highlights

60% of global oil production is produced using the artificial lift (AL)pump technique; more than 20% of the pumps used are electric submersible pumps (ESPs) [1,2]
We considered that pump intake pressure (PIP) deviations ± 5% were normal, implying that the ESP operated under maximum production conditions (Qmax) when PIP fell by 5% from the design value; the ESP worked under the minimum operating conditions when the PIP increased by 5% of the design value—any greater deviation indicated an abnormality
The intake node evaluation yielded the operating PIP given by the intersection of the tubing performance (TPR)-ESP and IPR curves

Summary

Introduction

60% of global oil production is produced using the artificial lift (AL)pump technique; more than 20% of the pumps used are electric submersible pumps (ESPs) [1,2]. An ESP is an artificial lifting device that features multistage centrifugal pumps, a motor, seals, power cables, and surface controls. Their applications are found in both on- and off-shore production facilities [3]. The horizontal well has played a significant role in developing unconventional reservoirs. It increases the contact between the target reservoir and the production well, leading to increased flow rate and recoverable oil [6]. An ESP reduces the bottom hole flowing pressure; it allows more efficient and consistent oil-lifting capacity at lower reservoir pressures than other artificial lifts. The application of the ESP in a horizontal well remains a critical issue since the presence of the free gas impedes its boosting pressure [9]

Methods

Results

Conclusion