Multiphase flows in oil-and gas pipelines involve a variety of different flow regimes. The different flow regimes are determined by the geometric arrangement of oil, gas and water inside the pipe, and evolve in a dynamic manner along a flowline, from bottom hole to receiving facilities. Along the path of the flow, the geometric fluid arrangements (or flow patterns), which develop dynamically, are often outside what is properly accounted for in existing 1D flow models. In such cases, more detailed multidimensional models are needed. As the industry is facing tighter operating margins and stricter regulatory frameworks, more accurate and predictive tools are needed. It is realized that CFD (Computational Fluid Dynamics) type models cannot replace 1D models in most cases, but will be an extremely valuable addition to the toolbox in cases where the 1D models may be insufficient.In the present paper a CFD method will be presented which enables such generic simulations. In this model, the physics of coexisting large scale interfaces and dispersed fields (droplets and bubbles) has been handled. Results obtained by a "Quasi-3D" implementation of the model will be shown for a number of important industrial applications. It will also be shown how such tools can also be applied to improve existing 1D frameworks, or directly to tackle multiphase production technology challenges.

There are several challenges associated to the pre-salt development at the Santos basin, such as long distances from the coast, low temperature reservoirs, high pressures, high water depth, among others. Additional aspects contributing to the complex production scenario are related to fluid characteristics and flow assurance. In particular, the high CO 2 content in the dissolved gas is an important characteristic that should be also analyzed, because CO 2 is not only a heavy component, when compared to lighter components present in the gas phase, but has also a high Joule-Thomson coefficient. This affects pressure drop and specially the mixture cooling behavior during decompression. The cooling effect is expected to be strong at high production rates. Thus, the objective of the present work is to evaluate these effects under present and future production scenarios, taking into account increasing CO 2 contents due to re-injection strategies.Two different field configurations were investigated and a variety of operating conditions was used, along with real and model fluids ranging from 5% to 50% CO 2 content (molar basis). PVT data for the model fluids with high CO 2 content were generated by a simulated swelling test with CO 2 of an existing mixture with lower CO 2 content. A parametric study was carried out aiming at investigating primarily the total pressure and temperature drop in the pipeline when the total CO 2 content of the mixture is increased. Furthermore, variation of the fluid properties along the well, flowline and riser was evaluated. Results are also discussed in view of the impact of increasing CO 2 contents and the challenges experienced during simulation of such flows.

A straightforward kinetic model for the hot metal desulphurization process is presented. The model contains some of the most important parameters and variables that govern the process. The inputs, outputs and parameters of a desulphurization program employed at industry are discussed. The model is able to cope with different injection policies of desulphurizers such as monoinjection, co-injection or multi-injection. When compared to the rotary impeller method, results of this model shows that the weight of lime consumed in the lance injection method is lesser than that consumed in the rotary impeller method for the same conditions of the hot metal charge.

The main components of the operational costs structure of the Kanbara Reactor, Magnesium Mono-Injection and Co-Injection desulphurization processes for hot metal are discussed here. The pros and cons of lime, magnesium and calcium carbide as desulphurization agents are discussed, too. The aim of this work is to compare the updated operational costs reported in the literature in the last decade among the above processes using the accumulated annual inflation rates of US dollar, euro and Indian rupees. Besides, the operational costs of the process are discussed in terms of the initial and final sulphur content and the degree of desulphurization. The KR process presents the lowest reagents costs, whereas the co-injection process presents the highest reagents costs. The KR process presents the highest iron and temperature losses given the great amount of slag generated and the intense agitation of the rotary impeller. The co-injection process presents an exponential growth of the desulphurization costs as higher desulphurization degree is required.