Natural Gas Processing -IntroductionDr. Stathis Skouras, Gas Processing and LNG

RDI Centre Trondheim, Statoil, Norway

Schedule

Tuesday 7/11/2017, 9:45 – 12:30

• Lecture 1: Introduction to Natural Gas

• Lectures 2 & 3: Natural Gas Processing

Thursday 9/11/2017, 11:45 – 13:30

• Lecture 4 – Natural Gas Processing

• Lecture 5 – Low Carbon technologies

• Kahoot quiz

2

Outline

Introduction

• Statoil

• Oil and Gas production

• What is Natural Gas

• Basic terminology

• The concept of “Gas Value Chain”

• Basic phase behaviour

3

4

5

6

7

8

9

Oil and gas production – is this the right picture conceptually?

10

Oil and gas production – This is the right picture!

11 -

Production from a typical gas-condensate well

• Gas and condensate/oil (multiphase flow)

• Water

− Water dissolved in hydrocarbon fluid

from the reservoir

− Produced water from the reservoir (free

water phase)

• Sand (should be removed)

• Inert gasses like Nitrogen and Argon

• Sour gases like H2S and CO2

• Heavy metals

− Mercury

• Salts (reservoir brine)

− Mainly NaCl, KCl, CaCl2, MgCl2, BaCl2

Transport from well to platform…

• Temperature reduces due to heat loss

from fluid to sea water

• Pressure drop due to friction

• Flow assurance issues (make things flow)

• Liquid drop out

− Water (from soluble water in the gas)

− Hydrocarbons (that condense)

− Injected chemicals for flow assurance

• Salt precipitation/scale

What is natural gas?

• Mixture of light hydrocarbons

• Mainly methane, ethane, propane and butanes

• Small amounts of pentane (C5) and heavier

components (C6+)

• Acid/sour gases such as CO2 and H2S

• Inerts such as nitrogen (N2)

• Water (vapour)

• Trace components such as mercury (Hg) and

sulphur compounds (S)

13

• 1 Sm3 = 1 m3 @ 15°C and 1 atm

• 1 Sm3 ≈ 770 gr

• Price ≈ 0.20 €/Sm3 (EU)

Natural gas compositions (typical values)

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Natural Gas Terminology

• Rich Gas: Rich in heavy components.

Further processing required

• Sales gas (dry gas): Ready for sale to

the market

• Liquified Natural Gas (LNG): -162°C @

1 bar

• Natural Gas Liquids (NGL): Ethane and

heavier HC (C2+)

• Naphtha: Rest of the NGL (C5+)

• Condensate: Heavier liquids from

integrated gas/oil production (C6+)

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C1 Methane

C2 Ethane

C3 Propane

IC4 Isobutane

C5+ Naphtha

C6+ Condensate

NC4 Normal butane

LNG: Liquefied

Natural Gas

(-162°C@ 1 atm)

NGL: Natural Gas Liquids

Sales gas/dry gas

LPG: Liquid

Petroleum

Gases

Terminology

Non-HC: N2, CO2, H2S, H2O

16

Liquefied Natural Gas (LNG)Pipeline gas

Natural gas transport

Pressure: 250 - 50 bar

Temperature: ambient temperature

17

Pressure: atmospheric

Temperature: -162°C (at boiling point)

• 8 000km of pipelines

• Production fields (offshore Norway)

• Transportation pipelines

− Rich gas

− Sales gas

− Oil/Condensate

• Gas processing plants (onshore Norway)

• Receiving terminals (continental Europe)

Norwegian Gas Transport Network

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Gas Value Chain

Offshore processesSubsurface

(reservoir, production

and wells, flow

assurance)

Gas Processing

(processing, extracting high added value products)Downstream

Onshore processes

Subsea and wells

Receiving terminals

19

Topside Facilities

(processing, prepare

for transport)

Midstream

Upstream

Upstream

Storage, Metering and Distribution

20 -

Basic phase behavior – phase envelopes

21

Presenters name: Dr. Stathis Skouras

Presenters title: Principal Researcher

efss@statoil.com, tel: +47 97 69 59 62

www.statoil.com

Thank you