石油工学

The development of offshore oil and gas basins such as in the North Sea and the Gulf of Mexico is increasingly characterized by “marginal” reservoirs. The main challenge facing the oil industry is to economically develop these discoveries. One of the major technical trends in the development of such marginal reservoirs is the drive towards total subsea production. All reservoir fluids will be transporteduntreated to a central process facility or ultimately to shore. The development of “multiphase production systems”, either in flow-lines to a central platform or in pipelines to shore, is favored due to important cost reductions resulting from the minimization of field process facilities and pipeline costs. For such a production concept to be a practical proposition, a high level of confidence is required in the application of the multiphase flow technology to the transportation of untreated reservoir fluids over long distances. Multiphase pumping is one of three main aspects of multiphse flow technology that requires further development to make such concepts workable. The development of pumps to handle multiphase flow constituting the full range of flow patterns and with gas void fractions from 0 to 100% is progressing, and some prototype units are currently operational. Japan National Oil Corporation has started R & D in this area, bringing together its expertise, research laboratories and teams since 1990.

Gas-liquid interfacial flows, such as liquid film flows (also known as wetting flows on plates), are encountered in many industrial processes including absorption, distillation and so on. The present study focuses on detailed descriptions of the flow transition phenomena between the film flow and the rivulet flow, as well as how such phenomena are affected by wall surface texture treatments.This study develops a numerical simulation technique using Computational Fluid Dynamics (CFD) with the Volume of Fluid (VOF) model as well as a lab-scale experimental testing technique. As the liquid flow rate is increased and then decreased, a hysteresis of the transition between the film flow and the rivulet flow is discovered, which implies that the transition phenomenon depends primarily on the history of the change of interfacial surface shape. Further study on the effect of texture geometry shows quantitatively that surface texture treatments added on the plate can help to prevent the liquid channeling and can increase the wetted area. The main reason for increasing the wetted area on the wavy surface is that the liquid film break-up is inhibited due to the liquid holding on the plate and the spreading of the liquid flow in spanwise direction by the wavy surface geometry. Additionally, the simulation results agree well with the experimental results in terms of the gas-liquid interfacial surface shape and the wetted area in the transition region between the film flow and the rivulet flow.

Petroleum refinery is an industrial plant where crude oil is processed and refined into more useful products such as gasoline, diesel fuel, kerosene and liquefied petroleum gas. Fluid catalytic cracking (FCC) is one of the most important conversion processes in a petroleum refinery, it also occupies very significant position in the refinery due to its economic benefits. RFCC is an extension of conventional FCC process, processing the heavier feedstock, and RFCC technology got great development around the reaction system, including the feeding atomization, quick separation of oil vapor and spent catalysis, steam stripping of high efficiency, temperature control of reaction as well as the innovation of riser reactor. This report shows the typical characteristics of RFCC process and introduces the results of several numerical studies.

The displacement of more viscous fluids by less viscous fluids in porous media provides not only an industrial application for enhanced oil recovery (EOR) from reservoirs, but also a fundamental study of the phase transition phenomena of fluids, combining fluid mechanics and thermodynamics. Recent studies have shown that the coupling of thermodynamic and hydrodynamic instabilities results in the formation of self-driven active fluid that significantly affects EOR. In this paper, we discuss the phase transition phenomena of the fluid in a porous medium simulating EOR from both hydrodynamic and thermodynamic aspects.