Performance Evaluation of a Density Measurement Tool for ESP Applications

Abstract

Knowledge of fluid densities in oilfield activities is vital during production operations. The information can be used to ascertain changes in the type of produced fluids, determine water cut, gauge equipment performance, etc. This study presents the evaluation of a measurement tool that can be installed with an electric submersible pump (ESP) to measure in-situ fluid densities during production operations. Such tools can also be configured for use in non-ESP applications. The density measurement tool has a 5.62-inch outer diameter, typical of some ESP components, which may be installed in a 7-in, 26 lb/ft casing. The tool consists of two flow sections with a 5-degree deviation angle. Total flow rates from the analysis were varied from 2000 barrels per day (bpd) to 12,000 bpd with water as the operating fluid. Pressure drop data within each flow section of the tool were obtained and the fluid densities determined. The estimated densities were compared with the known densities for water. The results indicate that the pressure drop measurements depend on the entry distance of fluid to the first measurement point within the tool. Other contributing factors include the distance between the measurement sensors and the deviation angle between the flow sections. These factors were optimized by incorporating flow symmetry into and out of the tool to ensure reduced variability of the pressure measurements and thus enable computation of the fluid densities. Overall, incorporating the two flow sections with known deviation angle was beneficial to reduce the complexity of estimating the fluid densities. Therefore, having a simple internal flow architecture in addition to optimized pressure measurement capabilities for each flow section has the potential to estimate fluid densities. Such a tool may be used as a means to measure in-situ and surface fluid densities from flows typical of oilfield production operations. The main benefit is to obtain instantaneous fluid density mesurements for more accurate production monitoring and faster decision-making during production with an ESP. This study presents a tool with a different internal architecture and a method that can be used to estimate fluid densities from flows typical of oilfield production operations. The tool architecture and measurement technique are simple and have the benefit of easy integration into a flow monitoring system. Such systems are of value to oilfield operators and stakeholders to optimize hydrocarbon flow and implement effective production management of field assets.