Semester of Graduation

Summer 2026

Degree

Master of Science (MS)

Department

Petroleum Engineering

Document Type

Thesis

Abstract

The present work challenges the idea of estimating the gas lift valves true dynamic stem position by providing an alternative capable of tracking the real stem position during flow tests. This is of interest for the improvement of performance determination tests and procedures that involve critical safety concerns, complex training and considerable investments, both in time and money. This scenario, together with the strong interest of industry for valve optimization and the scarcity of works available in literature, encouraged this study. An apparatus named Vision System was developed for tracking and measuring the stem position during flow tests. The developed apparatus enabled the visualization of stem movement in real time with reliable tracking and no valve intrusion. Modifications were made to an existing flow loop to accommodate the developed apparatus without compromising the capabilities of simulating field operation conditions. Tests were performed with a valve previously investigated to ensure that proposed changes did not impact performance determination. The result of this comparison showed less than 5% differences in the flow coefficients obtained and the final performance was no more than 10% divergent. Additional tests were carried out with two other valves and the proposed tool. The Vision System tracking capabilities in the flow loop were validated. A new performance curve correlation developed with stem tracking data showed better flow rate prediction than the literature reference. With no calibration, the vision correlation achieved 68.8% of calculated flow rate within ±20% of experimental values, while the literature methodology obtained 56.9% of points inside the same uncertainty range. The final apparatus was validated as a reliable tool for the determination of the stem position during flow tests, becoming a powerful asset for the determination of gas lift valves performance. The observation of the actual stem movement also opens a myriad of opportunities for further investigations of the physics assumptions and phenomenon on gas lift valves behavior.

Date

7-12-2026

Committee Chair

Waltrich, Paulo J.

LSU Acknowledgement

1

LSU Accessibility Acknowledgment

1

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