Analysis of the Dynamic Response of the Mechanism of Conventional Sucker rod Pumping Units

Abstract

In the kinetostatic study of the mechanism of the sucker rod pumping units, the cinematic motion parameters of the elements are considered to be known, assuming that the cranks have a constant angular velocity imposed by the operating functioning conditions of the pumping unit. The paper analyzes the dynamic response of the mechanism of these pumping units, which implies the determination of the variation of the angular acceleration of the cranks during the operating cinematic cycle. A series of results regarding the determination of the variation of the angular acceleration of the cranks during the cinematic cycle in the case of the mechanism of a C-640D-305-120 pumping unit are presented. The obtained results are checked by comparing the experimental curves of variations of the acceleration at the polished rod with those obtained by simulation using a computer program developed by the authors in which the angular acceleration of the cranks was taken into consideration. Keywords: sucker rod pumping unit, dynamic response, angular acceleration of the cranksEstablishing the variation of the angular acceleration of the cranks of the conventional sucker rod pumping units, which implies the determination of their dynamic response, is particularly important in assessing the operation of the entire pumping installation [1][2][3]. Obtaining high values of the angular acceleration of the cranks would reveal inadequate operation of the pumping unit, due to a poor balancing of the unit mechanism or due to the dynamics of the sucker rod string [4][5][6][7].The paper presents the way to determine the variation on the cinematic cycle of the acceleration of the cranks of the conventional pumping units by using the synthesis parameters of the dynamic model of their mechanism. The results obtained in the case of a C-640D-305-120 pumping unit were verified by comparing the experimental curves of the variation of the acceleration of the polished rod with those obtained by simulation using a computer program developed by the authors in which the angular acceleration of the cranks was taken into consideration. Total Well Management program [11] has been used for processing the experimental records and the computer program for simulations was developed with Maple programming environment [10]. Experimental partThe experimental records have been obtained from a well serviced by a C-640D-305-120 pumping unit manufactured by Lufkin [12] and were processed with the program Total Well Management [11]. For establishing the variation of the angular acceleration of the cranks were used the records concerning the variation of the force at the polished rod and of the motor moment at the crankshaft for the strokes 90 ( fig. 1) and 95 (fig. 2). *

Research Concerning the Static Balancing of a Multiloop Linkage

“…The dynamic analysis of the mechanisms used in various applications, many of them even in the oil field, is a subject of study that is always up to date [1][2][3][4][5][6][7]. The problems that need to be solved in this case are generally of great complexity and have as aim finding of optimal solutions for the functioning of the mechanisms [8][9][10][11][12][13][14].…”

Research Concerning the Simulation of the Operation of Conventional Sucker Rod Pumping Units

“…It is well known that conventional sucker rod pumping units are used intensively in oil extraction, so the study of their optimal operation represents a topical issue [1][2][3][4][5][6][7][8][9][10]. On the other hand, the study of the kinematics and dynamics of the mechanism of these pumping units is part of a broader issue specific to the theory of mechanisms and machines [11][12][13][14][15][16][17][18][19].…”