New Upstream Gas Treating Facilities To Maintain LNG Production Plateau.
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Transcript of New Upstream Gas Treating Facilities To Maintain LNG Production Plateau.
New Upstream Gas Treating Facilities To New Upstream Gas Treating Facilities To
Maintain LNG Production PlateauMaintain LNG Production Plateau
• Introduction• Offshore Facilities Description• Onshore Facilities Description• Onshore Facilities Study and FEED• Project Status• Conclusion
Presentation OverviewPresentation Overview
IntroductionIntroduction
• The Qatargas 1 LNG facility is divided into two sections:
Upstream facilities (offshore facilities, onshore receiving and condensate loading facilities). Downstream facilities (LNG Plants).
• There are now 4 Qatargas LNG ventures and this project relates only to Qatargas 1. • Qatargas 1 shareholders are; Qatar Petroleum (QP), Total, ExxonMobil, Marubeni and Mitsui. • LNG Trains 1 & 2 started in 1996 and Train 3 in 1998,
• The LNG plant also produces condensate and sulfur.
Offshore FacilitiesOffshore Facilities
• Reservoir: North Field (Khuff) reserve > 900 TSCF
• 2 production platforms accommodate 3 Trains
• 1 Living Quarter platform
• 3 Wellhead platforms with a total of 20 wells & 1 Flare platform.
Offshore Facilities Offshore Facilities
• To maintain the present LNG production plateau, it requires
drilling 4 new wells and re-completion 2 existing wells.
• The new wells have higher H2S content and it will result in 2.0 % mol of H2S in the combined feed gas to onshore
• Drilling of new wells are implemented in 2007 and 2011.
Onshore Facilities Onshore Facilities
Existing Facilities: • 3 LNG Trains, 2 Acid Gas Enrichment Units, 2 Sulfur Recovery Units.• 4 LNG storage tanks and utilities.
LNG Train 2
LNG Train 3LNG Train 1
Onshore Facilities StudyOnshore Facilities Study
• A Study was conducted to determine the impact of increasing H2S in the feed from its original design of 0.8 % mol to 2.0 % mole.
• Two approaches were studied:1- Revamp existing AGRU by adding pre-
Absorbers.2- Avoid revamping existing AGRU, provide
Pretreatment Acid Gas Removal Unit (PAGRU) as a new unit.
• Approach 2 was selected based on safety, construction, cost, schedule and plot plan utilization.
Onshore Facilities Study (approach 2)Onshore Facilities Study (approach 2)
AGR 1
AGR 2
AGR 3
0.7 % H2S2.3 % CO2
AGE 1
AGE 2
SRU 1
SRU 2
Lique. 1
Lique. 2
Lique. 3
PAGRU
Feed Gas From Slug Catcher
1720 MMscfd2.07 % H2S3.30 % CO2
0.0
6 %
H2
S
1.8
% C
O2
Ac
id G
as
Acid Gas
Sulfur
Sulfur
LNG
1100 MMscfd
620 MMscfd
: Solid line denotes new facilities
Existing Facilities
AGR 4 SRU 4Sulfur 880 t/d
Onshore Facilities Study – Process Selection Onshore Facilities Study – Process Selection
• The objective is to select the most suitable process for the new AGRU in terms of technology, experience, and process guarantee.
• Other criteria are selectivity in removing H2S from 2.07 % mol to 600 ppm mol and removing CO2 from 3.3 % mol to 1.8 % mol. Also, selective H2S removal from tail gas from new SRU to have H2S < 250 ppmV in treated tail gas.
• One third of feed gas will bypass the PAGRU. Treated gas from PAGRU is mixed with one third of raw feed gas. The recombined gas stream will contain 0.8 % H2S and 2.3 % mol CO2
(same level as current feed gas quality).
• Four process Licensors were evaluated. Process scheme proposed by Prosernat met the above objectives, criteria and minimum solvent circulation rates.
Onshore Facilities Study – Process SelectionOnshore Facilities Study – Process Selection
• Qatargas selected the AdvAmine™ MDEAmax process, developed by Total and licensed by Prosernat for the Acid Gas Removal Unit.
• KTI technology was used for the new Sulfur Recovery Unit and Tail Gas Treatment Unit.
• New SRU require H2S in acid gas of 54 % (min.) and also minimal aromatics present in the acid gas. Prosernat proposed modified process configuration (hot pre-flash low BTX scheme) consist of:
High Pressure Absorption Section Hot Pre-Flash Column Tail Gas Absorption Section Amine/MDEA Regeneration Section
New Acid Gas Removal Unit - FEEDNew Acid Gas Removal Unit - FEED
PAGRU Process Scheme with Hot Pre-Flash low BTX Configuration
SourGas
SRU
To Incinerator
Pre-treatedGas
Absorber
Tail Gas Absorber
Regenerator
Hot Pre-FlashColumn
Tail Gas
FlashedAcid Gas
FlashGas
AcidGas
New Acid Gas Removal Unit - FEEDNew Acid Gas Removal Unit - FEED
PAGRU Process Scheme with Hot Pre-Flash low BTX Configuration
SourGas
SRU
To Incinerator
Pre-treatedGas
Absorber
Tail Gas Absorber
Regenerator
Hot Pre-FlashColumn
Tail Gas
FlashedAcid Gas
FlashGas
AcidGas
Semi-lean solvent fromTG Absorber is
partially Recycled to HP Absorber
Total solvent flow Reduced by 20%
New Acid Gas Removal Unit - FFEDNew Acid Gas Removal Unit - FFED
PAGRU Process Scheme with Hot Pre-Flash low BTX Configuration
SourGas
SRU
To Incinerator
Pre-treatedGas
Absorber
Tail Gas Absorber
Regenerator
Hot Pre-FlashColumn
Tail Gas
FlashedAcid Gas
FlashGas
AcidGas
Hot Pre-Flash liberatesSelectively CO2 with
Most of the BTX
PAGRU Process Scheme with Hot Pre-Flash low BTX Configuration
New Acid Gas Removal Unit - FEEDNew Acid Gas Removal Unit - FEED
SourGas
SRU
To Incinerator
Pre-treatedGas
Absorber
Tail Gas Absorber
Regenerator
Hot Pre-FlashColumn
Tail Gas
FlashedAcid Gas
FlashGas
AcidGas
Acid gas enrichmentCan be achieved by:-Pre-flash pressure- Acid gas recycling
The Sulfur Recovery and Tail Gas Treatment Unit Consist of:
• Claus Section
• Tail Gas Treatment Section
• Thermal Incinerator Section
• Liquid Sulfur Degassing Section
• Sour Water Stripper (SWS)
New Sulfur Recovery Unit - FEEDNew Sulfur Recovery Unit - FEED
New Sulfur Recovery Unit - FEEDNew Sulfur Recovery Unit - FEED
CLAUS
SRU 4
TGT
SRU 4SWS
SRU 4
SULFUR DEGASSING
SRU 4
INCINERATOR
SRU 4
Acid Gas from AGR 4
Liq
uid
Su
lfur
Rich Amine to AGR 4
LP Flash Gas from AGR 4
Lean Amine from AGR 4
Sour Water
CLAUS Tail Gas
TGT By-Pass
Stripped Water
To NeutralizationFacilities
TG
T
Ta
il G
as
Vent Gas
Liquid Sulfur To Storage Tanks
Flue Gas To ATM
New Sulfur Recovery Unit – CLAUS SectionNew Sulfur Recovery Unit – CLAUS Section
ACID GAS
1stSTEAM
REHEATER
SULFUR
THERMAL REACTOR
WASTE HEAT BOILER
1st SULFUR CONDENSE
R
2ndSTEAM
REHEATER
1st CLAUSREACTOR
2nd CLAUSREACTOR
2nd SULFUR
CONDENSER
3rd SULFUR CONDENSE
R
SULFUR SULFUR
CLAUSTAIL GAS
ACID GAS PREHEATER
COMB.
AIR COMB. AIR PREHEATER
CLAUSBURNER
FUEL GAS
COMB. AIRFIRED
HEATER
FeedstockPre-heating
Main Combustion
Chamber
Claus Reactors
Sulfur Condensers
Project StatusProject Status
• FEED work will complete in September 2008
• Engineering Procurement Construction (EPC) will be developed after Contractor selection
• Project completion date in the first half of 2012
• Long Lead Items (LLI) procurement will be initiated 4 months prior to EPC award.
ConclusionConclusion
• The installation of pretreatment acid gas removal unit and related sulfur unit will limit the H2S content in feed gas to the existing trains at the current levels (approx 0.8 % mol).
• This will enable Qatargas to continue to saturate the LNG plant capacity and maintain its current LNG production rates plateau.