Mathematical Description and Experimental Analysis of Sucker Rod Pump Valve Movement of Sucker Rod Pump Life Extension

Research output: ThesisMaster's Thesis

Authors

Abstract

In the oil and gas industry, the sucker rod pump is a well-established and commonly used artificial lift system. While their operation is relatively straightforward, predicting the behavior of the downhole components can be challenging, primarily relying on approximations derived from dynamometer data gathered at the surface. The conversion of surface data to downhole movement is necessary due to the elongation of the sucker rod string, which can result in misinterpretations, reducing the efficiency of the artificial lift system and increasing operational costs. Technical failures may occur, requiring a workover, which can be time-consuming and costly. Thus, it is crucial to have a comprehensive understanding of the downhole component behavior to prevent operational inefficiencies and technical failures. This project focuses on the development and validation of a fluid dynamic model for sucker rod pumps, specifically in relation to the valve, and evaluates the pump under non-ideal operating conditions. The objective is to create a simulation model that accurately depicts the movement of the Sucker Rod Pump Ball Valve in relation to the downhole plunger's precise motion during various operation stages. Previous research has focused on estimating loads on the surface and evaluating downhole conditions using dynamometer cards, assuming the pump is running at ideal conditions. However, this project takes a bottom-up approach and considers the downhole components, factoring in the plunger kinematics as well as downhole pump condition and influencing parameters. A transient simulation model was developed by the simulation providing company AC2T research GmbH based on the Navier-Stokes equation to predict the valve closing times and impact speed on the seat during operation for changing ball density and valve geometry. To further develop the model, a 3D implementation was created, considering different valves used in the industry, and the model was validated by measuring the valve ball's position during operation as a function of time and impact speed at the Pump Test Facility at the Montanuniversity Leoben. After examining the critical speed in accordance with the square root law, the model was calibrated and verified. Overall, this thesis contributes to a better understanding of sucker rod pumps and their behavior under non-ideal operating conditions, which can lead to improved pump design and operation.

Details

Translated title of the contributionMathematische Beschreibung und Experimentelle Analyse der Sauggestängepumpen Ventilbewegung zur Lebensdauerverlängerung Sauggestängepumpen
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date30 Jun 2023
Publication statusPublished - 2023