doctoralThesis
Modelagem e simulação de uma unidade de bombeio mecânico convencional utilizando o ambiente Simscape Multibody™
Fecha
2021-10-18Registro en:
OLIVA, Gabriel Bessa de Freitas Fuezi. Modelagem e simulação de uma unidade de bombeio mecânico convencional utilizando o ambiente Simscape Multibody™. 2021. 167f. Tese (Doutorado em Ciência e Engenharia de Petróleo) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.
Autor
Oliva, Gabriel Bessa de Freitas Fuezi
Resumen
The Sucker-Rod Pumping (SRP) system is the most used artificial lift method in oil wells
in Brazil and in the world. The widespread use of this method can be justified by its
relatively simple, reliable and durable structure, convenient maintenance, etc. Due to the
popularity of the SRP systems in the oil industry, over the years, many studies have been
developed to contribute to the evolution of the method. Recent computational advances
have allowed the development of SRP simulators, as well as software for modelling and
simulation the SRP system. Thus, there is an opportunity to develop a more accurate
model, capable of accurately reflecting the operation of the Sucker-Rod Pumping Units.
In this context, this work proposes to model a conventional SRP Unit using the tools of
the Simscape Multibody™ (a MATLAB’s library of the Simscape™ environment for
modelling and simulation of physical systems), and to carry out specific studies with the
developed model that are not commonly seen in the current literature. Among these
studies, using the developed model, a sensitivity analysis was first performed with the
objective of evaluating how the inclusion of dissipative friction forces in the components
of the SRP unit can impact the resulting gearbox torque curve. Furthermore, simulations
were carried out with the objective of demonstrating how the application of a variable
speed drive profile throughout the pumping cycle (intra-stroke speed profile) can
contribute to the improvement of the equipment's operation. As a result of this study, it
was possible to demonstrate the feasibility of manipulating and redistributing the intrastroke speed profile to achieve objectives such as: counterbalancing the SRP unit and
keeping the gearbox maximum torque of the equipment within the recommended limits,
as well as reducing the region where the net torque values were negative. Additionally, it
was also possible to increase the pumping speed in the section where the net torque of the
system was negative, and the increase of the pumping speed did not cause an increase in
the maximum peak torque experienced by the equipment. This result is relevant because
it shows that is possible to improve the operation of the pumping units, considering that
the increase in speed can provide a greater oil flow rate due to a higher average pumping
speed. In order to validate the developed model, simulations were performed and the
obtained results were compared to other traditional calculation methodologies existing in
the literature. Moreover, it was analysed whether the behaviour of the modelled system
was consistent if compared to what can be seen in practice when certain procedures are
performed in real SRP units.