Presentation given in the upstream track at the Europe Simulation Software User Conference June 2018

1. A Pressure/Enthalpy Flash Formulation
What is it good for in Transient Multiphase Flow?
Johan Henriksson
Product Analyst Flow Assurance Engines

2. Schlumberger-Private
Outline
 Introduction
 Case Studies
– LNG Transport Line
– Geothermal Energy Production
 Summary

3. Introduction

4. Schlumberger-Private
The Challenge
Transient Multiphase Flow Simulations
 Model hours of operation for
– Wells
– Transport lines
– Networks
– …
 Planning and Operation

5. Schlumberger-Private
The Challenge
Fluid Modeling
 Computational cost is proportional to
the complexity of the methods
 Fluid modeling
– Precalculate fluid properties
– Compositional Tracking
• Computational cost: ~ 5 times
N2, H2S, CO2, C1, C2,...PS1, PS2...
N2, H2S, CO2, C1, C2,...PS1, PS2...
N2, H2S, CO2, C1, C2,...PS1, PS2...

6. Schlumberger-Private
Fluid Modeling
Pressure / Temperature (PT) vs. Pressure / Enthalpy (PH)
 PT formulation
–
𝑑𝑚 𝑔
𝑑𝑡
=
𝜕𝑚 𝑔
𝜕𝑇 𝑝
𝜕𝑇
𝜕𝑡
+
𝜕𝑚 𝑔
𝜕𝑝 𝑇
𝜕𝑝
𝜕𝑡
– May be infinite
 PH formulation
–
𝑑𝑚 𝑔
𝑑𝑡
=
𝜕𝑚 𝑔
𝜕𝐻 𝑝
𝜕𝐻
𝜕𝑡
+
𝜕𝑚 𝑔
𝜕𝑝 𝐻
𝜕𝑝
𝜕𝑡
– Finite
• Computational cost: ~ 5 times

7. Schlumberger-Private
Fluid Modeling
Phase Diagrams and Quality Lines
Single component Multi-component HC
50°C
25 bar

8. Examples
Applications of pressure/enthalpy formulation

9. Example 1
LNG Transport Line

10. Schlumberger-Private
 Inlet temperature : -156°C
 Outlet pressure : atmospheric
 Steady operation
LNG Transport Line
Inlet
Outlet
?

11. Schlumberger-Private
LNG Transport Line

12. Example 2
Geothermal Energy Production

13. Schlumberger-Private
Geothermal Energy Production

14. Schlumberger-Private
Geothermal Energy Production
Production Well Operation

15. Schlumberger-Private
Geothermal Energy Production
Injection Well Design
 Reinject 100% of produced fluids
– Optimal gas injection depth?
– Instabilities?
NCG
Composition
Fraction Fraction of
Other
CO2 97.5%
H2S 2%
Other 0.5% 100%
NH3 9.03%
Ar 0.06%
N2 6.79%
CH4 38.50%
H2 45.62%Mixing Depth [mMD]
0 250 500 750 990 1250
Injection Pressure
NCG [bara]
22.0 33.1 42.7 52.4 58.4 63.3
Injection Pressure
Brine [bara]
22.0 6.3 0.4 0.4 0.4 0.4 Stacey, Norris, and Lisi.
40th GRC Annual Meeting, 2016.

16. Schlumberger-Private
Geothermal Energy Production
Injection Well Operation
Stacey, Norris, and Lisi. 40th GRC Annual Meeting, 2016

17. Summary

18. Schlumberger-Private
Summary
OLGA
+
Multiflash
+
Pressure/Enthalpy Flash Formulation
=
New, exciting application areas

19. Thank you!