Mejores Prácticas

Simulación para la industria de Hidrocarburos.

4 Proyectos Relevantes.

Dr. Humberto Hinojosa Dr. Moisés Hernández

Hidrodinámica y dispersión del efluente del difusor marino de la Terminal Marítima

Dos Bocas, Tabasco.

Descripción: El sistema de disposición final de aguas congénitas, derivadas del proceso de acondicionamiento de hidrocarburos en la terminal marítima de dos bocas, cuenta con pozos letrina y un difusor marino. El presente estudio tridimensional busca describir de forma detallada la dispersión de sal y el perfil de temperaturas en el área alrededor del difusor marino así como establecer el área de impacto de dicha descarga. Datos Importantes:

Descarga: 90,000 ppm de sal

34 ºC 300,000 BPD

Agua de mar:

36,00 ppm de sal 24 ºC

Corrientes marinas.

Ubicación:

Diseño:

Diseño:

Parte 1: Difusor

Parte 1: Difusor

Parte 1: Difusor

Parte 1: Difusor

Parte 1: Difusor

Resultado:

Perfil de flujo de agua congénita a lo largo del difusor.

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Parte 2: Difusor + Entorno

Resultados:

Perfil de concentraciones de sal.

Perfil de temperatura.

Área de impacto delimitada.

Plataforma de Estabilizado y Cabezal de Gas.

Modelo geométrico tridimensional estructural de los equipos, líneas, válvulas y accesorios.

Cabezal de recolección de gas – TMDB

Cabezal de recolección de gas – TMDB

Cabezal de recolección de gas – TMDB

Hydrodynamic Analysis of the Dehydration Process of one Mexican Oil in an Electrostatic Vessel using

ANSYS CFX

Objectives:

• Crude oil dehydration. • Meet quality standards. • Evaluate performance equipment under different

operation conditions.

Electrostatic Separator Vessel: Main components:

• Vessel • Emulsion Distributor. • Water Collector. • Oil Collector. • Electrodes.

Vessel

Water Collector

Emulsion Distributor

Shrouds

Electrodes:

Oil Collector

Internals

Internals

Internals Details

Complete Geometric Model

Complete Geometric Model

Complete Geometric Model

Complete Geometric Model

Hydrodynamic Analysis: Domain Discretization. Fluids Properties. Physical Models. Results.

Discretization

Discretization 5 Million Elements Free Mesh

Mesh Detail

Wired Model

Fluids Properties Oil: Density: 19 oAPI Viscosity: 10 cP Flow: 200’000 BPD Water: Density: 998.7 kg/m3

Viscosity: 0.29 cP Interfacial Tension: 25 dina/cm Flow: 66’667 BPD Mean Particle Diameter: 400 micron

Hydrodynamic Model No homogeneous Multiphase Flow (Euler-Euler). Continuous Phase – Oil Dispersed Phase – Water Isothermal: 220 oF Drag Coefficient: Ishii – Zuber (1979). Ishii,M., Zuber, N. (1979).”Drag coefficient and relative velocity in bubbly, droplet or particulate flows”, AIChE Journal, 25(5), pp. 843-855.

Flow Morphology Isao Kataoka, Kenji Yoshida, Masanori Naitoh, Hidetoshi Okada and Tadashi Morii (2012). Transport of Interfacial Area Concentration in Two-Phase Flow, Nuclear Reactors, Prof. Amir Mesquita (Ed.), ISBN: 978- 953-51-0018-8, InTech, Available from: http://www.intechopen.com/books/nuclear-reactors/transport-of- interfacial-area-concentration-in-two-phase-flow

Electrocoalescence Model A.K. Das, J.R. Thome and P.K. Das, Transition of Bubbly Flow in Vertical Tubes: New Criteria Through CFD Simulation, J. Fluids Eng. 131(9), 091303 (Aug 18, 2009) (12 pages).

Electrocoalescence Model P. Atten, "Electrocoalescence of water droplets in an insulating liquid", J. Electrostatics, vol. 30, pp. 259–270, 1993. J. Raisin, “Electrocoalescence in water-in-oil emulsions: towards an efficiency criterion”, PhD thesis, Grenoble University, 2011.

Water Particles Polarization.

Electrostatic Forces between two polarized water Droplets.

Melheim, J. A., Chiesa, M., Ingebrigtsen, S., Berg, G., 2004. Forces between two water droplets in oil under the influcence of an electric field. In: 5th Inter- national Conference on Multiphase Flow. Yokohama, Japan, paper # 126.

Interfacial area density transport equation. G. Kocamustafaogullari and M. Ishii, “Foundation of the interfacial area transport equation and its closure relations,” International Journal of Heat and Mass Transfer, vol. 38, no. 3, pp. 481–493, 1995. M. Ishii and S. Kim, “Development of one-group and two-group interfacial area transport equation,” Nuclear Science and Engineering, vol. 146, no. 3, pp. 257–273, 2004.

Source Term. R=Collision Frequency X Coalescence Efficiency

J. Raisin, “Electrocoalescence in water-in-oil emulsions: towards an efficiency criterion”, PhD thesis, Grenoble University, 2011.

Results: Pressure Field

Results: Oil Velocity Field

Results: Oil Velocity Vectors

Results: Water Velocity Field

Results: Water Volume Fraction

Results: Mean Particle Diameter

Results: Mean Particle Diameter

Capabilities: Separation Efficiency Determination as function: Process Variables: Temperature. Flow. Water Content. API degrees.

PVT module coupled with ANSYS-CFX

Basic Ideas:

• In order to perform reliable CFD simulations for the Oil & Gas industry, it is important to know:

What kind of fluid are we dealing with? Heavy Oil. Light Oil. Gas – Condensate.

How many phases will be present for a given process? Liquid – Vapor. Liquid – Liquid. Liquid – Liquid – Vapor. Fluid – Solid.

What are the physical properties for each phase? Density. Viscosity… at least.

Basic Ideas:

• All this information can be obtained from what in the Oil & Gas Industry is known as “PVT Module”. To extend the application of CFX to deal with complex fluids

such as reservoir fluids, an easy connection between a PVT module and ANSYS CFX is needed.

In this presentation, we would like to show the connection between a PVT module and ANSYS CFX.

Outline:

• Characterize a reservoir fluid using an “In-House” developed PVT Module. Cubic Equation of State based Software. PVT calculations: Bubble points. Dew points. Flash at constant T and P.

• Generate physical properties for EVERY possible phase present for a given process.

• Generate intput data file for a Fortran Compiled Library. (PVT – ANSYS connection)

• Read CCL file to use the Library. • Perform CFD simulation using the calculated properties.

Characterize a reservoir fluid: “In-House” developed PVT Module

Composition of the reservoir fluid

Characterization Options for the Heavy Fraction.

Characterization Options for the Heavy Fraction.

PVT experiments that can be simulated:

• Phase Envelope • CCE • DLE • CVD • MMP • Swelling Tests

Phase Envelope

Calculation Progress

Phase Envelope

DLE

Calculation Progress

DLE

Properties DATA file in library path

ANSYS configuration after CCL file has been imported

Simulation Results Example:

Flashing of a Volatile Oil flowing through a butterfly valve

41 0API Oil RGA : 67.40

Pressure Field

Velocity Field

Gas Volume Fraction

Simulation Results:

Real properties for the 2 phases (gas and oil)

Equilibrium line crossing implies a

phase change. (Flashing)

This module was used along with ANSYS – CFX in the following project:

Hydrodynamic Description of a 140 km

crude oil transport line.

Fluid Properties:

35 oAPI RGA: 8

14%Vol. Water Content

Fluid Characterization and Properties:

Componente % mol PM (g/mol) Tc (K) Pc (bar) ω

N2 0.00061 28.01 CO2 0.00087 44.01 H2S 0.00346 34.08 C1 0.01231 16.04 C2 0.01267 30.07 C3 0.02299 44.10 iC4 0.00692 58.12 nC4 0.02829 58.12 iC5 0.01654 72.15 nC5 0.02953 72.15 C6 0.05455 84.00

Pseudo1 0.14158 102.54 557.43 33.93 0.31074 Pseudo2 0.24920 147.65 626.71 29.02 0.40041 Pseudo3 0.23146 233.29 737.83 19.60 0.63706 Pseudo4 0.13852 370.19 840.28 13.59 0.92242 Pseudo5 0.05050 588.11 938.69 9.63 1.25656

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Complete Line – Pressure Drop

Complete Line – Phase Change

Complete Line – Water Bed

Predicted Oil volume loss due to evaporation

Thank you for your time!

Q & A?