Banca de DEFESA: LEONARDO ASFORA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : LEONARDO ASFORA DE OLIVEIRA
DATA : 30/07/2017
HORA: 09:00
LOCAL: SALA DE REUNIÕES DO CTEC (312)
TÍTULO:

ANALYSIS ON THE APPLICATION OF SURFACE EJECTORS TO INCREASE  PRODUCTION IN OIL WELLS

PALAVRAS-CHAVES:

artificial lift methods, pumping, submergence, annulus, casing pressure, ejector, CFX, nodal analysis, Electrical Submersible Pump

PÁGINAS: 125
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
RESUMO:

When the reservoir doesn’t have enough energy to raise the fluids to the surface or when its natural flow rate isn’t economically viable, artificial lift methods are required. Among these there are those that are called pumping methods, which rely on bottomhole pumps. Because of their working principle, the performance of these pumps decrease when free gas is ingested. Therefore, sometimes gas separators are installed upstream of the pump in order to redirect some of the gas to the annulus, and the completion is made without a packer. The annulus and the production line are connected via a check valve, allowing gas flow from the annulus to the production line whenever the casing pressure is higher than the wellhead pressure. However, in some cases the wellhead pressure is high enough, causing the gas to get trapped in the annulus, increasing casing pressure and therefore reducing pumps’ submergence. In the worst case scenario, when the reservoir is depleted, the casing pressure comprises significant part of the bottomhole pressure. When this is the case, the fluid level become very close to the suction ports, provoking flow instabilities or, in some cases, making it unfeasible. This dissertation intends to study one possible solution to this problem, which came about as part of a partnership between Petrobras and UFRN, which is the installation of an ejector in the production line. Ejectors are devices that utilizes the energy of a motive fluid in order to suck a secondary one. In this particularly application, the well’s own production is used to suck the separated gas from the annulus. Throughout the text, a simplified mathematical model is developed in order to conduct performance analysis and design by using the basic principles of conservation of mass, momentum and energy for control volumes. This model was verified with the aids of computational fluid dynamics, where the software CFX from ANSYS version 16.0 was utilized. Finally, ejector’s influence on an well equipped with an Electrical Submersible Pump is discussed utilizing nodal analysis, where it was shown that it’s possible to increase flow rate when a Variable Speed Drive (VSD) is available, maitaining the same submergence.

MEMBROS DA BANCA:
Presidente - 1288120 - ADRIANO DOS SANTOS
Externo à Instituição - BENNO WALDEMAR ASSMANN - PETROBRAS
Externo ao Programa - 1566922 - LINDEMBERG DE JESUS NOGUEIRA DUARTE
Externo ao Programa - 1714956 - RUTACIO DE OLIVEIRA COSTA