Buzios FPSO Experience: Standardization and Perspectives for Our Next Generation of Pre-Salt FPSOs

The purpose of this article is to present a set of experiences and challenges related to the current Buzios FPSOs and the perspectives offered by these related experiences, which should drive further enhancements for next generations of pre-salt production units. Buzios field is a giant oil discovery located at Brazilian southeast coast and has four production systems already in operation: P-74, P-75, P-76 and P-77. Throughout these projects, Petrobras observed technical and business opportunities that are going to lead improvements for next generation of Buzios field's FPSOs. These include enhancements on high production wells, H2S removal technology, vessel standardization, digital transformation solutions, design procedures improvements and several measures to strength the integration between design, construction, commissioning and operation phases. During the construction, commissioning and startup period of the Buzios’ current installed units, Petrobras identified technical issues that should be addressed in order to add value to the next generation of Buzios’ FPSOs. These experiences point out to the need of technical design improvements and reviews such as: change in technology of H2S removal from solid bed to membranes; a complete analysis of hull capacities and dimensions and standardization of the vessel; and a set of standardization methods and processes to develop the basic design - including aspects of digital transformation. The result was a standard design project called Reference Project ("Projeto de Referência" in Portuguese) that intends to be a reference for new units to be installed in Buzios field. This design also intends to be the basis to other projects in order to allow faster business decisions.

Determinantes de desempenho em joint ventures internacionais brasileiras

Purpose – Investigate the Joint Venture International performance determinants’ relevance at each point of their life cycle.Design/methodology/approach – Determinants already mapped in the literature were identified and grouped into three dimensions: internal, industrial and institutional. A questionnaire was developed and sent to academics and managers, which requested them to order the dimensions and determinants presented. Data was analyzed using Multi-Attribution Global Quality Inference (MAGIQ).Findings - Results show that the dimensions’ relevance varies according to the organization’s stage in its life cycle. The internal dimension has more influence on performance during the startup period than the industrial and institutional dimensions, but this position is reversed when the IJV becomes mature.Research limitations/implications (if applicable) – This study is based on specialists’ perceptions about IJV’s, so could be a gap between this perception and the facts that the organizational indicators can present.Practical implications – Understanding IJV’s performance determinants’ relevance at each point of their life cycle can help manage these variables to create more efficient actions in accordance to the company’s needs.Originality/value (mandatory) – this study frames performance determinants in the three proposed dimensions within strategic administration theories, ranks them and uses MAGIQ for data analysis.

Study on the Transient Characteristics of the Centrifugal Pump during the Startup Period with Assisted Valve

The startup period, one of several transient operations in a centrifugal pump, takes note of some problems with these devices. Sometimes a transient high pressure and high flow rate over a very short period of time are required at the startup process. The pump’s dynamic response is delayed because of the rotational inertia of the pump and motor. Our research focuses on how to get a large flow in a short time when the pump cannot meet the requirements alone without a large power driver. To achieve a strong response in the startup process, a ball valve is installed downstream of the pump. The pump’s transient behavior during such transient operations is important and requires investigation. In this study, the external transient hydrodynamic performance and the internal flow of the pump during the transient startup period are studied by experiments and simulations. In order to find an appropriate matching method, different experiments were designed. The content and results of this paper are meaningful for performance prediction during the transient pump-valve startup period.

Transient Characteristics of Water-Jet Propulsion with a Screw Mixed Pump during the Startup Process

In order to investigate the transient hydrodynamic characteristics of water-jet propulsion with a screw mixed pump during the startup period and to overcome the difficulties in measuring the transient process parameters over a very short period of time, a method based on a flume experiment combined with computational fluid dynamics (CFD) is proposed. The thrust and torque of the pump-jet propulsion according to mooring status at different rotational speeds were measured by the test, which provided a group of data for the boundary and initial conditions of the numerical calculation of the user-defined function (UDF). Consecutive changes in the parameters of the water-jet propulsion dynamics can be captured from the numerical simulation of the startup process with the UDF. Thus, the transient hydrodynamic characteristics of water-jet propulsion according to time or rotation speed were obtained. The results show that the relationship between the thrust or torque of the water-jet propeller and pump rotational speed is close to the quadratic functions. The energy characteristic parameters of screw mixed water-jet pump, such as the flow rate, head, shaft power, and efficiency, rapidly increase and decrease and then remain relatively stable.

Particle image velocimetry experiment of the inlet flow field in a mixed-flow pump during the startup period

The transient characteristics of the inlet flow field of mixed-flow pump during start-up process are hard to be measured experimentally. The elbow structure with viewport is designed before the mixed-flow pump for capturing the transient inlet flow fields of the mixed-flow pump. Meanwhile, the synchronous data acceptance system is also designed to collect the data from different sensors synchronously. Besides, uncertainty analysis is carried out after the experiment to ensure the accuracy and reliability of this test system. The transient external characteristics are obtained and the velocity distribution of a mixed-flow pump during the startup period is measured using particle image velocimetry technique. The results show that the overall uncertainty for the external characteristics was 0.2345%, which indicates the high accuracy of this test bench for capturing the transient flow condition in the mixed-flow pump during the startup period. At the beginning of the start-up process, the head of the mixed-flow pump increases and reaches the maximum once the rotation speed meets the maximum value and an instantaneous impulsive head appears at the end of the accelerating process. However, with the increase of the rotating speed, wall boundary layer gradually develops from laminar to turbulent flow, and the flow moves continuously from the hub center to the inlet. At the end stage of the accelerating process, more intensive entrainment effect of the impeller is found. When the rotation speed is steady, the influence of the elbow on the internal flow fields gradually decreases, compared with the startup process. The results can serve as a fundamental reference for the investigation of transient flow characteristics of the mixed-flow pump during the startup period.

Numerical Investigation of Transient Flow in a Prototype Centrifugal Pump during Startup Period

Transient performance of pumps during transient operating periods, such as startup and stopping, has drawn more and more attentions recently due to the growing engineering needs. During the startup period of a pump, the performance parameters such as the flow rate and head would vary significantly in a broad range. Therefore, it is very difficult to accurately specify the unsteady boundary conditions for a pump alone to solve the transient flow in the absence of experimental results. The closed-loop pipe system including a centrifugal pump is built to accomplish the self-coupling calculation. The three-dimensional unsteady incompressible viscous flow inside the passage of the pump during startup period is numerically simulated using the dynamic mesh method. Simulation results show that there are tiny fluctuations in the flow rate even under stable operating conditions and this can be attributed to influence of the rotor–stator interaction. At the very beginning of the startup, the rising speed of the flow rate is lower than that of the rotational speed. It is also found that it is not suitable to predict the transient performance of pumps using the calculation method of quasi-steady flow, especially at the earlier period of the startup.