IPTC 17273

Qatargas Flare Reduction Program I. Bawazir, M. Raja, and I. Abdelmohsen, Qatargas Operating Company Limited

Copyright 2014, International Petroleum Technology Conference This paper was prepared for presentation at the International Petroleum Technology Conference held in Doha, Qatar, 20–22 January 2014. This paper was selected for presentation by an IPTC Programme Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the International Petroleum Technology Conference and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the International Petroleum Technology Conference, its officers, or members. Papers presented at IPTC are subject to publication review by Sponsor Society Committees of IPTC. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the International Petroleum Technology Conference is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Write Librarian, IPTC, P.O. Box 833836, Richardson, TX 75083-3836, U.S.A., fax +1-972-952-9435

Abstract Qatargas produces 42 Million Tonnes Per Annum (MTA) of Liquefied Natural Gas (LNG). The Qatargas facilities comprise seven LNG Trains, including four of the world’s largest mega-trains, which were commissioned between 2009 and 2011. Routine baseline flaring is encountered during normal LNG plant operations due to the essential requirement to maintain purge gas flow within the flare system to prevent air ingress and consequent explosion hazards. During unplanned facility trips, restarts or planned facility shutdowns, process gas is also flared per operational requirements. Qatargas has made significant progress in reducing flaring from its LNG trains in line with the increased national focus on flare minimization and the Company’s desire to reduce its emissions and carbon footprint. This has been made possible through operational initiatives on source reduction, increased plant reliability, reduced shutdown/start-up flaring and a sustained focus on flare minimization facilitated by multi-disciplinary Flare Management Teams (FMTs). Enhanced acid gas recovery and operational excellence initiatives on source reduction and plant reliability at Qatargas’ older, conventional LNG trains have successfully reduced flaring by more than 70% between 2004 and 2011. A comprehensive project is currently underway at the LNG mega-trains to reduce current baseline purge flaring by approximately 70%. Qatargas is also undertaking a long-term capital project to install interconnections between LNG mega-trains to re-route gas encountered during process events rather than flaring. Additionally, Qatargas’ pioneering Jetty Boil-off Gas Recovery (JBOG) Project, which will commence operation in 2014, is expected to reduce LNG loading flaring by over 90% and recover approximately 600,000 tonnes per year of flared gas. This paper provides an overview of Qatargas’ flare management approach, the Company’s main drivers and challenges for flare reduction and the various initiatives currently underway to manage and minimize flaring. These include the major capital projects noted above as well as enhanced awareness, monitoring and reporting, and operational source reduction successes. Facility and Flare Systems Overview

Qatargas’ LNG operations are based in Ras Laffan Industrial City (RLIC), Qatar, and centered on the four LNG assets described below.

• Qatargas 1 (QG1): Three conventional C3MR LNG trains (Trains 1-3). Commenced operations in 1996. Each train

has a production capacity of 3.3 MTA (total QG1 production of 10 MTA). Offshore facilities include the manned North Field Bravo (NFB) complex with three wellhead production platforms.

• Qatargas 2 (QG2): First mega-trains in the world, each with a capacity of 7.8 MTA. Commenced operations in 2009.

Both trains (Trains 4 and 5) utilize the Air Products AP-XTM hybrid liquefaction process which allows for higher LNG production by adding a third Nitrogen (N2) refrigeration cycle to the conventional C3MR process. Offshore facilities include three unmanned wellhead platforms.

• Qatargas 3 (QG3) and Qatargas 4 (QG4): Although separate assets with different shareholders, both facilities are

operated jointly as Qatargas 3&4 (hereinafter referred to as ‘QG3&4’) by a combined operations team. QG3&4

2 IPTC 17273

consists of two LNG mega-trains (Trains 6 and 7) based on the AP-XTM process and each with a production capacity of 7.8 MTA. Train 6 (QG3) commenced production in late 2010 and Train 7 (QG4) in early 2011. Offshore facilities include three unmanned wellhead platforms.

In addition to LNG trains, Qatargas also operates the Laffan Refinery (LR), which commenced operations in 2009 with a nameplate processing capacity of 146,000 Barrels per Stream Day (BPSD). Qatargas, through its Ras Laffan Terminal Operations (RLTO) group, is also the operator (on behalf of other producers within RLIC) of multiple hydrocarbon storage tank farms and loading facilities as well as a Common Sulfur Plant (CSP). These common tank farms cater to LR feedstock and products, Liquefied Petroleum Gas (LPG), Gas to Liquids (GTL) plant products and low sulfur condensate. The common loading facilities include Liquid Product Berths (LPBs) and an offshore Single Point Mooring (SPM) for field condensate loading. The large number of operating assets and facilities described above require multiple flare systems, which can be described as follows:

• Onplot Flares (within main LNG plant site):

§ QG1: Four independent flare stacks. Main stack includes separate headers for dry, wet and sour gas. Steam-assisted smokeless tips on dry and wet headers. Separate upstream (inlet reception) and onplot LNG tankage flare stacks.

§ QG2 and QG3&4: Large combined flare system for all four mega-trains. Two 200-m flare stacks. Separate headers for dry, wet and sour gas. Steam assisted smokeless tips on dry and wet headers.

• Offplot Flares (various locations outside LNG plant site):

§ LR: Single stack and header to flare offgases from refinery units as well as LPG, hydrogen and sour gas during plant upsets.

§ Common Lean LNG Tankage: Single stack with main and spare headers to flare Boil-off Gas (BOG) from storage of lean LNG supplied by four Qatargas mega-trains and two RasGas mega-trains.

§ Common LPG Tankage: Two single-header stacks to flare BOG (only required during BOG compressor upsets).

§ LPG Loading: Single stack and header to flare BOG from LPG ship loading (only required in case of ship BOG compressor upset).

§ LNG Loading: Each of Qatargas’ four LNG berths or jetties are equipped with a dedicated flare stack to flare BOG generated during ship loading.

§ Offshore: One dedicated offshore flare platform at the QG1 NFB complex and dedicated flares on the three QG3&4 unmanned wellhead platforms (pilots not continuously lit, required for emergency use only).

Building on lessons learned from Qatargas’ older trains, the LNG mega-trains were designed and constructed with the following inherent (existing) flare reduction measures:

• Shared Flares: One set of sour gas, wet gas and dry gas flares serve four LNG mega-trains as discussed above. This

minimizes continuous flaring due to additional purge and flame shaping gas.

• Process Gas Recovery/Recycling: Recycling to process and fuel systems (instead of flaring) of spent C3/C4 molecular sieve regeneration gas, de-propanizer overhead, Main Cryogenic Heat Exchanger (MCHE) shell vent gas, and propane and Mixed Refrigerant (MR) accumulator vent gases.

• Inter-Asset/Train Process Crossovers: Uni-directional interconnections available between Inlet Reception (IR) facilities for QG2 (to QG1) and QG3&4 (to QG2) to re-route offshore gas during full start-up (instead of flaring). Acid Gas Removal (AGR) and Natural Gas Liquid (NGL) Fractionation units of two mega-trains interconnected with crossover lines to re-route gas during trips and start-ups instead of flaring.

• Process Equipment Design and Sparing: All four mega-trains equipped with spare offgas and BOG compressors as well as spare Pressure Relief Valves (PRVs) to minimize flaring during compressor downtime or PRV repair.

The Qatargas LNG facilities and onplot flare systems are shown in Figure 1.

IPTC 17273 3

Figure 1: Qatargas LNG Trains and Onplot Flare Systems

Flare Reduction Challenges The challenges faced by Qatargas in managing and reducing flaring are based primarily on the inherent nature of a LNG plant. The flare system in a LNG plant is a critical process safety unit designed to provide an uninterrupted path to gas release during process upsets as well as start-ups and shutdowns. These inherent design issues as well as other technical and non-technical challenges are summarized in Table 1 below.

Table 1: Qatargas’ Flare Reduction Challenges

Challenges What They Entail

Inherent nature of LNG process

• What makes LNG plants different from other facilities in terms of flaring?

• Process Units Connected in Series: Unless the next unit in series is not operationally ready (warmed up) to receive gas or if its gas specification/acceptance requirements are not met by the preceding unit, gas must be flared. This is of particular importance prior to refrigeration, where any off-specification (offspec) gas containing heavy hydrocarbons (C3+) and other impurities will freeze up in the MCHE.

• Higher Potential for Process Upsets: Due to the serial arrangement of units within a train, an upset in one unit typically results in rundown interruption (also called ‘trip’) of downstream units that need to be restarted. In case of major upsets, an entire LNG train may ‘trip’ and require restart.

• Sparing of Critical Equipment: Critical rotating equipment such as the propane and MR refrigerant compressors do not have spares. A trip of any of these compressors results in flaring from the entire refrigeration section of the train.

• Storage and Retention: There is no option to store or retain large amounts of offspec gas from a process upset. A limited amount of flared gas may be re-routed to other gas processing plants via the national grid but this is subject to strict specification requirements and capacity restrictions.

Reducing unplanned flaring events

• Continual challenge in maintaining and improving rotating equipment performance rates and overall plant reliability.

Mega-train design

• Higher throughput = higher flaring inventories during upsets, shutdowns and restarts. • Mega-train throughput at 7.8 MTA is 2.3 times more than Qatargas’ conventional (3.3 MTA) trains.

Reducing flaring during trips and shutdowns

• Challenge to reduce this flaring via optimized procedures in a safe and operationally flexible manner and implement long-term engineering projects to recover and re-route flared gas instead of flaring.

Qatargas 3 and Qatargas 4 (2010-2011)Two 7.8 MTA LNG mega-trains

Qatargas 2 (2009)Two 7.8 MTA LNG mega-trains

Qatargas 1  (1996)Three  3.3  MTA  LNG  trains

QG2 and QG3&4 combined flare system• Two 200-m flare derricks.• Separate headers for dry, wet,

sour gas.• Steam-assisted smokeless tips

on dry and wet headers.

QG1 flare system• Four flare derricks.• Separate headers for dry, wet, sour gas.• Steam-assisted smokless on dry and

wet flares.• Two upstream LP and MP flares.• One onplot LNG tankage flare.

4 IPTC 17273

Table 1: Qatargas’ Flare Reduction Challenges

Challenges What They Entail

Safely minimizing baseline flaring

• Continuous purge gas flaring is a design requirement to protect against air ingress and potential explosion hazards. • Any reduction in purge gas rates must be achieved safely without compromising plant integrity and flare system

availability.

External Factors • Safely minimizing flaring due to upsets resulting from external factors such as offshore and onshore power outages and common facility system failures (e.g., trip of RLIC common seawater cooling pumps).

Regulators and stakeholders

• Regulator and other stakeholder understanding of requirement for continuous purge gas flaring and need to flare during process upsets, shutdowns and start-ups.

• Nature of LNG facilities precludes operation at ‘zero’ flaring levels. • Permitting realistic, practical and attainable flare minimization targets/limits.

Flaring targets and goals

• Setting realistic internal targets and KPIs. • Maintaining and enhancing flare management awareness and focus. • Inter-disciplinary action and management commitment to meet these targets in a practical, planned manner.

Drivers for Flare Reduction at Qatargas Qatargas’ drivers for flare reduction are multi-faceted and include Qatargas’ Direction Statement and Corporate Social Responsibility (CSR) commitment and their alignment with Qatar National Vision (QNV) goals, regulatory flare reduction requirements, and the Company’s obligations to its stakeholders, including the community in which it operates. These drivers and their interlinkages are described briefly in Figure 2 below.

Figure 2: Qatargas’ Flare Reduction Drivers

Qatargas Direction Statement

• Company’s strategic vision and Primary driver for flare reduction.

• Qatargas Vision 2015: Become world’s premier LNG Company. Four pillars:

§ People § Innovation § Operating Excellence § Corporate Social Responsibility.

Corporate Social Responsibility (CSR)

• Goal: Conduct business in ethical, responsible manner, caring for our people, their families, environment and communities.

• 48 identified CSR performance elements distributed among four pillars: Governance and Conduct; Financial and Economics; Social; and Environment.

Key CSR Performance Elements

National and Regulatory Initiatives • Target of 0.3% flaring of sweet gas production included in operating

permits for all gas processing facilities by Qatar Ministry of Environment (MoE).

• Significant initiative led by HE Minister of Energy and Industry in 2011: § All flaring reported monthly directly to HE’s office. § Implement operational measures and engineering (capital)

projects to reduce flaring.

Qatargas’ Flare Management Approach • Three pillars: enhanced awareness, monitoring and

reporting; operational, reliability and maintenance initiatives; and flare reduction capital projects.

• Flaring accounted for 11% of Qatargas’ total GHG emissions in 2012 (see Figure 3 below). Decrease from 21% in 2010.

• Environmental Policy • Environmental

Management System

• Climate Change / Greenhouse Gas (GHG) Emissions

• Emissions to Air (non-GHG)

• Stakeholder Engagement

Stakeholders and Communities • Increased awareness and focus on flaring from local community as well as

shareholders. • Increasing queries from local community on flaring and air quality issues. • Flaring performance reported in annual CSR reports available to public

(Ref. 3-5).

Qatar National Vision (QNV) 2030 • Holistic strategy for Qatar’s national

development. • Flare management enshrined in QNV

2030 (Ref. 1). • Specific national flare reduction targets

part of National Development Strategy (NDS) (Ref. 2).

• Qatargas’ vision and targets in line with QNV 2030.

Global Initiatives • Qatar signatory to Kyoto Protocol and host of

2012 Conference of Parties (COP18) meeting. • Qatar member of World Bank Global Gas

Flaring Reduction (GGFR) partnership since 2009.

• Qatargas involved with GGFR through its primary shareholder Qatar Petroleum (QP).

• Qatargas winner of 2012 GGFR ‘Excellence in Flaring Reduction Award’.

IPTC 17273 5

Current Flaring Performance and Sources A summary of Qatargas’ flaring performance from 2009 until June 2013 (inclusive) is provided in Figure 3 for all LNG assets. Flaring from Qatargas’ LR and RLTO assets is very minor (approximately 2% of total flaring) and is not discussed further. As evident from Figure 3, Qatargas has sustained significant reductions in flaring on the order of 50-60% since 2009. These reductions were achieved based on the key initiatives listed below.

• Establishment of Flare Management Teams (FMTs) for each asset. • Awareness, recognition and commitment to reduce flaring. • Enhanced monitoring, tracking and reporting which facilitated a continual flare management focus. • Operational source reduction comprising minimization of flaring during train trips, shutdowns and restarts. • Increased experience with mega-train operation. • Increased plant and equipment reliability.

These initiatives form the core of Qatargas’ Flare Management Approach. An interesting point to note, with regard to the above list and the data depicted in Figure 3, is that management and operational initiatives alone resulted in substantial flaring reductions. These represented ‘low-hanging fruit’ that were implemented rapidly as opposed to longer-term and complex engineering capital projects. Also depicted in Figure 3 are Qatargas’ main flaring sources since 2009 and how they have been managed and reduced. Jetty flaring (i.e., BOG flared from LNG ship loading) accounts for the majority of flaring at LNG assets (25-40%, based on 2011-2013 trends) followed by baseline purge gas flaring (19-21%), train and unit trips (15-17%) and planned shutdowns (6-22%). Minor flaring sources, which include small unit trips, short-term offspec production and equipment purging range from 9 to 14%. As evident in Figure 3, the above-listed initiatives were successful in reducing flaring from planned shutdowns (22 to 6%) and train and unit trips (17 to 15%) between 2011 and 2013. These flare reduction success stories are described in detail in forthcoming sections of the paper. It should be noted that the reductions in flaring from shutdowns and train/unit trips (as described above) result in a proportional increase in the contribution of other flaring sources which cannot be minimized through operational initiatives alone as shown in the pie-charts in Figure 3. These include jetty flaring, baseline purge gas flaring and to a large extent, train and unit trips themselves. Flare reduction engineering projects for each of these flaring sources/sectors are currently in progress (discussed in upcoming sections). The differences in flaring sources between Qatargas’ conventional LNG trains (QG1) and mega-trains (QG2 and QG3&4) are illustrated in Figure 4. The most apparent difference is for baseline purge flaring, which due to the combined and larger flare system is much higher for the mega-trains. As the QG1 trains have been in operation since 1996 and due to their smaller flare system, purge gas flaring has been optimized at much lower rates than currently operationally possible for the mega-trains. The relatively higher proportion of QG1 jetty flaring (46% vs. 35% for mega-trains) is indicative of lower gross flaring from non-jetty sources such as train/unit trips and shutdowns. These reductions were made possible through operational initiatives and facilitated by the smaller size and less complex operation of the QG1 trains (discussed as a case study in upcoming sections). Operational initiatives have also been successful in reducing flaring from shutdowns and train/unit trips at the mega-trains, however, the magnitude of this reduction has been limited by the inherently large and complex design of the mega-trains. Additional reductions in flaring from these sources as well as purge gas at the mega-trains may only be realized through flare reduction and gas recycling projects which are currently being implemented for QG2 and QG3&4. Flaring contributes directly to the Company’s overall emissions fooprint which represents a key CSR performance element for Qatargas as described in Figure 2. This direct link is demonstrated in Figure 5 below which depicts the contribution of flaring to overall GHG emissions from Qatargas’ facilities. As evident from Figure 5, the decrease in flaring GHG emissions from 21% in 2010 to approximately 11% in 2012 (approximately 45% reduction) is proportional to a similar reduction in overall flaring as shown in Figure 3.

6 IPTC 17273

Figure 3: Qatargas Flaring Performance (2009 - YTD 2013)

Figure 4: Conventional vs. Mega-Train Sectoral Highlights (2012)

3.12%

2.91%

1.91%

1.57%

1.19%

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

2009 2010 2011 2012 YTD2013

Flaringas  %  of  S

weet  G

as  Produ

ction  

Train  and  Unit  Trips17%

SD11%

Purge20%

Minor  Flaring  Sources9%

Tankage  Flaring6%

Jetty  Flaring37%

Train  and  Unit  Trips17%

SD22%

Purge19%

Minor  Flaring  Sources13%

Tankage  Flaring3%

Jetty  Flaring26%

Train  and  Unit  Trips15%

SD6%

Purge21% Minor  

Flaring  Sources  14%

Tankage  Flaring5%

Jetty  Flaring38%

Notes  for Figures  4  and  5:1.  YTD  2013  represents data  up  to  and  including  June  2013.2.  Flaring  data  presented  above  is  based  on  hydrocarbon  flaring  only  and  does  not  include  non-­‐hydrocarbon  streams  such  as  nitrogen  purging  or  CO2 offgas.    3.  Flaring  data  presented  above  is  for  all  Qatargas  LNG  assets  and  includes  onplot  and  offplot  flaring  but  excludes  offshore  flaring.  Qatargas'  LR  and  RLTO  assets  are  also  excluded.4.  %  sweet  gas  production  data  is  based  on  sweet  gas,  excluding  Natural  Gas  Liquids  (NGL),  prior  to  liquefaction.  5.  'SD'  refers  to  planned  maintenance  shutdowns.  6.  'Minor  flaring  sources'  includes  small  unit  trips,  short-­‐term  offspec  production  and  equipment  purging.

2011

2012

YTD  2013

Train  and  Unit  Trips,  16%

SD,  10%

Purge,  22%

Minor  Flaring  Sources,  11%

Tankage   Flaring,  6%

Jetty  Flaring,   35%

QG2,  QG3&4  LNG  Mega-­‐Trains  -­‐ 2012

Train  and  Unit  Trips24%

SD15%

Purge9%

Minor  Flaring  Sources0.5%

Tankage   Flaring5%

Jetty  Flaring46%

QG1  Conventional  LNG  Trains  -­‐ 2012

IPTC 17273 7

Figure 5: Flaring Contribution to Overall Qatargas GHG Emissions (2010 – 2012)

Qatargas Flare Management Approach Qatargas’ Flare Management Approach is summarized in Figure 6 and comprises three main pillars with the overall aim of minimizing flaring while providing due consideration to:

• Operational Flexibility: The inherent nature of a LNG plant requires flaring during process events; and • Safeguarding Asset Integrity and Process Safety: The flare system is primarily, a process safety device and requires

continuous baseline purge gas flaring to prevent air ingress and maintain its operability at all times.

Figure 6: Key Pillars of Qatargas’ Flare Management Approach

Flare Reduction Pillar #1: Enhanced Awareness, Monitoring and Reporting The first step of Qatargas’ Flare Management Approach is promoting and maintaining awareness and organizational buy-in

of the importance of flare reduction, coupled with continual improvement in flare measurement, tracking and reporting to provide a sound basis for flare minimization at an operational level. This is accomplished through the key initiatives described below.

69%

17%

14%

2011

Combustion Inherent  (Feed  CO2) Flaring

71%

18%11%

2012

65%

14%

21%

2010

Qatargas Flare Management

I. Enhanced Awareness, Monitoring and Reporting • Flare Management Teams (FMTs) for each LNG asset. • Increased internal awareness at all organizational levels. • Better monitoring and reporting internally and externally.

II. Operational, Reliability and Maintenance Initiatives • Operational source reduction and optimization of shutdown and

restart philosophy to reduce flaring. • Increased plant and equipment reliability through Reliability Centered

Maintenance (RCM) and robust preventative maintenance programs.

III. Flare Reduction Capital Projects • Jetty Boil-off Gas (JBOG) Recovery Project – recovery and recycling

of BOG flared during LNG ship loading. • Onplot engineering projects at mega-trains:

• Short-term Purge Gas Reduction Project. • Long-term Flare Reduction Project, focused on re-routing

and reuse of process gas during flaring events.

8 IPTC 17273

Flare Management Teams (FMTs) Multi-disciplinary teams have been established for each LNG asset, which provide a common platform for internal

stakeholders to coordinate their efforts on flare reduction. These FMTs meet regularly (minimum monthly) to review flaring performance for each asset, and explore measures (operational, maintenance or best industry practice) to minimize flaring. A summary of key initiatives championed by the FMTs is provided below.

• Minimization of non-routine flaring events and maintenance of facility flaring at minimum required baseline purge

gas levels. • Flare reduction during process events through optimized operational practices and procedures. A smaller Operations

team has recently been established as an FMT sub-group to review mega-train trip, shutdown and restart scenarios and incorporate improvements in current procedures to minimize flaring.

• Surveillance and mitigation of ‘bad actors’, i.e., units and components causing frequent flaring. This mitigation may include relatively simple operational fixes or more detailed engineering and reliability analyses.

• Flare meter performance tracking and implementation of quarterly and annual calibration/validation programs. • Minimization of differences (‘deltas’) between end-of-line flare meter readings and baseline purge gas rates. These

differences are typically accounted for by small flaring sources such as passing valves. A recent mitigation measure championed by the FMTs was the acquisition of an acoustic meter to verify valve passing to flare. A regular valve monitoring program is currently being implemented using this acoustic meter.

• Review and improvement of flaring calculations and reporting procedures. Discussion and alignment on external stakeholder queries or clarifications on submitted flare reports.

Advanced Flare Metering All Qatargas LNG assets are equipped with flare meters as summarized in Table 2 below.

Table 2: Qatargas LNG Asset Flare Meters

Asset No. of Flare Meters Type Flare Headers (no. of flare meters)

QG1 4 General Electric (GE) single-path ultrasonic flare meters (USMs)

+ 7% mass flow accuracy

Wet gas (1), dry gas (1), sour gas (1), spare (1)

QG2 4 Wet gas (1), dry gas (2*), sour gas (1)

QG3&4 6 Wet gas (2**), dry gas (2*), sour gas (2**)

Notes: * Two dry gas flare headers for each mega-train asset. Flare meters installed on both dry gas flares #1 and #2. ** Additional flare meters also provided on wet and sour gas sub-headers from Inlet Reception (IR) facilities to provide specific quantification of flaring from IR units. These sub-headers join the main wet and sour gas flare headers from LNG trains and Sulfur Recovery Units (SRUs). - One USM also installed on LR flare.

The flare meters listed in Table 2 are linked to Qatargas’ Plant Operating Information System (POISS) allowing data to be harvested on a real-time basis. Flare meter installation on separate flare headers facilitates accurate quantification of flared volumes on a per-stream basis, whether the flaring is wet, dry or sour gas. This allows for rapid identification of the main flaring sources within the LNG facilities during a process event. The flare meter set-up on the combined QG2 and QG3&4 flare system is depicted in Figure 7.

In addition to flare meters, separate meters are also provided to measure baseline purge gas flow to each header. All purge

gas is sweet fuel gas provided via a large number of flow/transfer points to each header. Each of these points is equipped with a separate flow meter (typically small orifice-plate meters) connected to POISS. During non-flaring days, the flare meter readings (on the main header) are equal to or higher than the sum of individual purge gas meters linked to that header. Any difference between the two represents actual flaring.

Individual units and equipment vent to flare through flare valves. All major flare valves within the LNG assets are

connected to POISS allowing valve openings to be viewed on a real-time basis. While valve opening flow rate determinations are imprecise, these openings, nonetheless, provide an essential indication of which specific unit or equipment is venting to flare.

An example of how flare meters, purge gas meters and flare valve openings are utilized to analyze specific process events

is provided in Figure 8. The case shown is for a trip of QG3&4 Sulfur Recovery Unit #1 (SRU-1) on 15 August 2013. The unit was immediately shut down and restarted on 17 August 2013. The resultant flaring is measured by the QG3&4 sour gas flare meter (58FI840013), which indicates mass flow (in tonnes/hour) as well as Molecular Weight (MW) of the flared gas. The short-term spike in MW from normally 20 g/g-mole (indicative of baseline purge gas flow only) to 35 g/g-mole is indicative of sour gas flaring resulting from the event. The actual flared gas volume is essentially the difference between meter 58FI840013 reading and the sum of purge flows to the sour gas header as shown in Figure 8. From the valve openings, it can be determined that the flaring resulted from Acid Gas Enrichment (AGE) Section of the SRU.

IPTC 17273 9

Figure 7: QG Mega-Train Flare System with Flare Meter Setup

Figure 8: Flare Tracking Example – QG3&4 SRU-1 Trip (15-18 August 2013) Qatargas’ flare meters (USMs) undergo quarterly and annual verifications. The quarterly checks are primarily diagnostic

and conducted in-house and involve collection of gas samples from the flare header which are used to calculate the ‘theoretical’ Speed of Sound (SOS) and MW of the gas. These theoretical values are compared with equivalent flare meter

Main Sour Gas Flare Rate (tonnes/h) Sour Gas Flare Purge Gas (t/h) Sour Gas Flare MW (g/gmole) Valve Opening to Flare #1 Valve Opening to Flare #218/08/2013 12:00:00 AM15/08/2013 12:00:00 AM 3.00 days

QG3&4 SRU-1 Trip on 15 Aug 2013

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

• SRU trip on 15 Aug. • Acid Gas Enrichment (AGE)

Section depressurized to flare.

Difference between flare meter and purge indicative of minor flaring sources such as passing valves and equipment purging with N2.

Valves remain open to flare to maintain AGE section on standby and vent N2 purge to flare

MW drops back down to slightly higher than purge due to N2 purging of AGE section.

• MW typically ~20, reflective of majority purge gas in flare header.

• MW spike to ~35 during trip indicates sour gas flaring.

Flare valves in AGE section opened to flare.

• AGE section restarted. • Once acid gas specs for next

unit (Claus Section) attained, flaring is stopped and valves closed.

58PT840072 58FI840072

barg t/h

58FI840013

t/hbarg

58PT840013

58FI840073

kg/h58FI840074 58PT840074

barg58PI840073 t/h barg

BPRV

28PT840072 28PT84001328PT840074 28FI840074

barg bargbarg kg/h

28FI840072 28FI840013 28PI840073BPRV

kg/h kg/hr barg58PT840222 58PT840399

28FI840073barg barg

kg/h58FI840222 58FI840399

t/h t/h

Flare  Stack  #1

"28" Prefix  '28'  refers  to  QG2

"58" Prefix  '58'  refers  to  QG3&4

28FL8401 Wet  Gas  Flare Wet  Gas  Flare  System FI Flare  Meter Flare  Stack  #2

28FL8402 No.1  Dry  Gas  Flare LP  Acid  Gas  Flare  System PT Pressure  Transmitter

28FL8403 LP  Acid  Gas  Flare Dry  Gas  Flare  System  No.  1  Stack V Flare  knockout  drum  or  vessel

28FL8404 Spare  Flare Dry  Gas  Flare  System  No.2  Stack SRU Sulfur  Recovery  Unit28FL8405 No.2  Dry  Gas  Flare IR Inlet  Reception

BPRV Buckling  Pin  Relief  Valve.  Normally  closed.

28FL8405

28FL8404 28FL8401

28FL8402 28FL8403

58V8421

QG2  IR

58V8402

28V840428V8401 28V8403 28V8402

QG3&4  IR

58V8403

58V8401

QG2  Train  4

QG2  Train  558V8404

QG3&4  Train  7

QG3&4  Train  6

58V8423

QG2  Utilities

QG2  SRUs QG3&4  Utilities

QG3&4  SRUs

10 IPTC 17273

SOS and MW readings. If the relative difference is greater than 2%, the theoretical SOS and MW are entered into the USM. Annual flare meter validations are performed by the vendor (GE) and include mechanical inspection of flare meter components, transducer cleaning, input/output verifications and zero flow calibration using a ‘zero flow’ or vacuum box. Recent flare meter modifications on the mega-trains include provision of a Modbus link which allows multiple signals to be sent to POISS. This provides additional meter data for surveillance and diagnostics including SOS, gas velocity, signal strength as well as flare meter measurement in different units (e.g., tonnes/hour, kg/hour, Million Standard Cubic Feet per Day [MMSCFD]).

Extensive Internal and External Reporting Qatargas follows a comprehensive internal and external flare reporting program which is summarized in Table 3. All data

reported in internal and external reports is based primarily on flare meter readings and is subject to strict data validation requirements.

Table 3: Qatargas LNG Asset Flare Reporting Program

Type of Report Recipients

Management and Internal Stakeholders

Regulators – MoE and RLIC Regulators – QP3 Shareholders

Daily1 X Flaring Event Notifications2 X X Weekly X X Monthly X X X Quarterly X X X Annual X X X X Notes:

1. Flaring rates and events reported daily in operational shift reports. 2. Per operating permit requirements, flaring incident reports submitted to regulators within 3 working days of each flaring event. 3. Monthly flaring report submitted to Qatar Petroleum (QP) via Qatargas CEO’s office. QP in turn reports performance to Qatar Ministry of Energy and Industry (MoE&I).

Flare Reduction Pillar 2: Operational, Reliability and Maintenance Initiatives

The two case studies included in this section describe how operational, reliability and maintenance initiatives have been successfully implemented at the QG1 conventional LNG trains and the QG2 LNG mega-trains to reduce flaring.

QG1 – Sustained Flare Reduction (2004-2013) A timeline of flare reduction initiatives and associated improvements in flaring performance at QG1 is summarized in

Figure 9. These items can be broadly classified as follows:

• Elimination of chronic flaring sources (‘bad actors’) through reliability studies and implementation of low-investment mitigation plans.

• Implementation of Reliability Centered Maintenance (RCM), based on preventive maintenance optimization to minimize equipment failures and trips.

• Optimization of operational procedures to reduce flaring during trips, shutdowns and restarts. Main objective is to achieve desired product quality while maintaining operation inside design envelope.

• Intensive site surveillance for potential passing valves into flare system. As noted in Figure 9, QG1 has made significant improvements in shutdown flaring performance starting with the total

shutdown in April 2012. Although the April 2012 shutdown was a total shutdown of all three QG1 trains as well as associated IR, SRU and Utilities facilities, a flare minimization plan was implemented which resulted in flaring comparable with (and in some cases lower than) previous single train shutdowns. This shutdown flare reduction plan was developed around the following main aspects:

• Flaring estimation and targets for each individual unit. • Cascading of flaring plan to shift supervisors, panel operators and all Operations teams involved in shutdown and

start-up to ensure understanding and compliance. • Clear instructions to Operations team to monitor and optimize flaring in line with plan. • Minimization of on-spot flaring in each phase of shutdown and start-up (e.g., during cold section defrosting and

draining). • Specific emphasis on monitoring and optimizing unit start-up as follows:

• Unit 2 (Acid Gas Removal): Consumption of BOG instead of flaring, thus producing fuel gas from same

IPTC 17273 11

train and avoiding flaring. • Unit 5 (Refrigeration): Unit stabilization while maintaining minimum gas throughput. • Unit 7 (NGL Fractionation): Optimizing parameters to stabilize unit in shortest time possible, thereby

minimizing flaring. • Unit 8 (Nitrogen Rejection): Close monitoring of Main Cryogenic Heat Exchanger (MCHE) pre-cool down

and final cool down temperatures.

A similar plan was also implemented for the QG1 Train 3 shutdown in May 2013 which resulted in a flaring reduction of more than 50% compared with previous single-train shutdowns (see Figure 9).

Figure 9: Timeline of QG1 Flare Reduction Initiatives

QG2 – Mega-Train Operational Flare Reduction (2012-Present) Flaring reductions at Qatargas’ mega-trains have been characterized by optimization of operational procedures, particularly

during train trips, shutdowns and restarts. A combined QG2 and QG3&4 Operations team was recently established as an FMT sub-group to explore opportunities to reduce flaring during process events through better operational controls and procedures. This team meets on a weekly basis to review previous process upsets and flaring events and recommend revisions to existing operational procedures and shutdown/start-up sequences to reduce flaring, or develop new procedures and sequences where none currently exist.

This sub-section describes how the above improvements have been implemented at the QG2 mega-trains to reduce flaring

during actual process events. For illustrative purposes, three types of process events are discussed herein: ‘Cold Section’ Trip; ‘Hot Section’ Trip; and Full Train Restart.

2.6%

2.4%

2.0%

1.5%

0.8%

2.13%

1.24%

0.71%

0.61%

0.46%

0.0% 1.0% 2.0% 3.0% 4.0% 5.0%

2004

2005

2006

2007

2008

2009

2010

2011

2012

YTDJune2013

QG1  Onplot  Flaring  -­‐ %  of  Sweet  Gas  Production

Operational Initiatives (2011 – Present)•Purge gas reduced to <0.1% sweet gas production (~1 MMSCFD).•Frequent field surveys to identify passing valves.•Flare critical valves equipped with alarms for better tracking and visible on operator panels. •Optimized shutdown (SD) and restart procedures:

•QG1 total SD flaring in April 2012 reduced to ~900 MMSCF for 3 trains (comparable to previous single-train SDs)•QG1 Train 3 SD flaring in May 2013 ~388 MMSCF (> 50% lower than previous single-train SDs)

Ultrasonic flare meters (USMs)•Installed (2009) to provide accurate flare volume data. Control valve calcs discontinued. ForceMajeure Event •QG1 total shutdown for 2 weeks due to failure of seawater intake transformer in Jan. 2009.Chronic bad actors•End Flash Gas (EFG) compressor trips due to seal failures.•Deethanizer flaring due to MCHE LPG coil choke.•Eliminated/mitigated by early 2010 through reliability studies and mitigation actions during operations and shutdowns.

Active source reduction•Flare CVs monitored daily.•Abnormal CV openings flagged and rectified.

Reliability studies•Detailed analysis of critical equipment trips between 2005-2007.•Implementation of mitigation actions in early 2008.

Smokeless flare tips•Steam assisted tips installed at wet and dry gas flares.

Acid Gas Enrichment (AGE) installation at SRUs•SRU efficiency boosted from 80 to 99%.•20kTPA acid gas flaring reduced.

Notes:•On-plot flaring data, excluding jetty and offshore flaring. •Hydrocarbon-only flaring data, excluding non-HC streams such as N2 purging and CO2 offgas. •% sweeet gas production based on sweet gas, excluding NGL.•YTD 2013 represents data up to and including June 2013.

12 IPTC 17273

As background to the upcoming discussion, an overall process flow diagram is provided in Figure 10, which summarizes the process sequence, main equipment, feed/product streams and major flaring points within a mega-train.

Figure 10: Qatargas Mega-Train Overall Process Flow

Each process unit within a mega-train is designed to be operated at a specific minimum turndown rate (i.e., minimum

process throughput) to achieve the required specification for natural gas processing and liquefaction. These turndown rates, as summarized in Table 4 below, therefore represent the natural maximum limit for flare reduction based on operational intervention only. Process throughputs below these rates will not allow the units to meet gas specification requirements resulting in flaring of gas throughput.

Table 4: Qatargas Mega-Train Minimum Turndown Rates  

Unit   Unit  Name   Produced  Gas  Minimum  Turndown  Limit  (MMSCFD)  

Recommended  by  Process  Licensor  (Qatargas  operational  optimization)  

02 Acid Gas Removal Sweet gas 250 (200)

03 Dehydration, Mercury and Mercaptans Removal Dry sweet gas 320 (320)

04 NGL Recovery Lean sweet gas 600 (450)*

05,06 Gas Chilling and Liquefaction Raw LNG 580 (580)**

08 Nitrogen Rejection Lean LNG and EFG 580 (580)**

* Minimum turndown for hot section of mega-train (Units 02-04) ** Minimum turndown for cold section of mega-train (Units 05-08) EFG: End flash gas (40% N2 fuel gas) MMSCFD: Million standard cubic feet per day

Feed Gas

Bi-directional line to other train

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

To QP

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

To DGF

To Fuel GasAGR

Knockout Drum

DryerA

DryerB

DryerC

DryerD

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

1460 MMSCFD 55 oC, 68 barg

[Unit 02 - AGR]

AGR Absorber

Activated Methyl Diethanolamine (aMDEA) absorption of acid gases (CO2, H2S) Molecular sieve dryer beds • Turbo-expander process to

extract NGL (C3+) from the feed natural gas from Unit 03.

• Mixed NGL stream fractionated in to propane, butane and plant condensate products.

Mai

n C

ryog

enic

Hea

t E

xcha

nger

(M

CH

E)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

• After pre-cooling in the C3Pre-coolers, feed gas is liquefied in the MCHE, which uses MR as refrigerant.

• It is then sub-cooled in the SCHE, which uses N2 as the refrigerant.

• LNG treated to reduce N2 content to spec for ship transportation and then transferred to storage tanks.

• Separated, N2-rich 'end flash' gas compressed and delivered to Fuel Gas System.

Legend:• MMSCFD: Million Standard Cubic Feet per Day• AGR: Acid Gas Removal• NGL: Natural Gas Liquids (C3, C4 and C5+)• QP: Qatar Petroleum national grid• WGF: Wet gas flare• DGF: Dry gas flare• MR: Mixed refrigerant (C1-C3)• EFG: End flash gas (40% N2 fuel gas)

• Feed gas• Flare control measure• Flared gas• NGL stream• LNG product

IPTC 17273 13

Flare Reduction Scenario #1 - Cold Section Trip  A cold section trip is an upset of the refrigeration section (Units 05-08) of the mega-train and typically results from a trip

of the MCHE or the main C3 or MR compressors as shown in Figure 11 below. This is the most common LNG train trip. During a cold section trip, flaring results from Units 02 and 04 due to back-pressure as flow to the cold section is stopped. The magnitude of this flaring depends on how quickly flare reduction procedures can be applied following the trip.

• Earlier Qatargas Practice:

§ Feed gas reduced from 1,460 MMSCFD to 600 MMSCFD* immediately following cold section trip (*earlier minimum turndown recommended by process licensor to keep Unit 04 operational).

§ Flaring continues from Units 02 and 04 as shown in Figure 11 below until cold section is restarted. § Actual Event: Train 5 MR Compressor trip on 12 April 2011 - approximately 101 MMSCF flared**.

• Flare Reduction Practice: § Feed gas now reduced to 450 MMSCFD* following cold section trip (*new operational minimum turndown

for Unit 04). § Lean gas from Unit 04 exported to QP national grid (≤250 MMSCFD). § Same lean gas also supplied to combined asset fuel system from tripped train (≤150 MMSCFD). Fuel gas

supply from other operating train minimized. § Due to feed gas reduction to 450 MMSCFD and export to QP and fuel gas system from Unit 04 (total 400

MMSCFD), wet gas flaring from Unit 02 is eliminated and dry gas flaring from Unit 04 reduced from 450 MMSCFD (earlier practice) to 50 MMSCFD.

§ Actual Event: Train 4 C3 Compressor trip on 10 January 2013 - approximately 43 MMSCF flared**.

(**Represents total flaring volume over the few hours of trip event only (total MMSCF and not MMSCFD). Does not include flaring from restart of units or train.)  

Figure 11: Mega-Train Flare Reduction – Cold Section Trip

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

To DGF

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

LNG  

Reduce feed rate to

600 MMSCFD

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er

(SC

HE

)

Tripped

~150 MMSCFD flared~450 MMSCFD flared

EARLIER PRACTICE

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

To DGF

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

LNG  

Reduce feed rate to

450 MMSCFD

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er

(SC

HE

)

Tripped

Flaring EliminatedReduced to ~50 MMSCFD

~250 MMSCFD To QP

~150 MMSCFD to Fuel Gas

NEW FLARE REDUCTION PRACTICE

14 IPTC 17273

Flare Reduction Scenario #2 - Unit 04 Trip A trip of Unit 04 (NGL Recovery) typically results from an upset in its Fractionation unit, Gas/Gas Exchangers or De-

ethanizer Column. This is a common LNG trip scenario during which flaring results from Unit 02 (Acid Gas Recovery) due to back-pressure as flow to Unit 04 is stopped. The magnitude of this flaring depends on how quickly flare reduction procedures can be applied following the trip.

• Earlier Qatargas Practice:

§ Feed gas reduced from 1,460 MMSCFD to 250 MMSCFD* immediately following Unit 04 trip (*earlier minimum turndown recommended by process licensor).

§ Flaring continues from Unit 2 (as shown in Figure 12) at rate of 250 MMSCFD until Unit 04 is restarted. § Actual Event: Train 4 NGL Recovery trip on 12 July 2011 - approximately 144 MMSCF flared**.

• Flare Reduction Practice: § Feed gas now reduced to 200 MMSCFD* following Unit 04 trip (*new operational minimum turndown for

Unit 02). § Approximately 200 MMSCFD of sweet gas (after acid gas recovery in Unit 02) diverted to other running

train through bi-directional line (as shown in Figure 12), which eliminates wet gas flaring from Unit 02. § Feed gas input to the other running train is reduced from 1,460 MMSCFD (normal) to 1,260 MMSCFD in

order to accommodate 200 MMSCFD from Unit 02 of the tripped train. § Actual event: Train 4 NGL Recovery trip on 14 September 2013, approximately 16 MMSCF flared**.

(**Represents total flaring volume over the few hours of trip event only (total MMSCF and not MMSCFD). Does not include flaring from restart of units or train.)

 

Figure 12: Mega-Train Flare Reduction – Unit 04 Trip

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

~250 MMSCFD flared

Reduce feed rate to

250 MMSCFD

EARLIER PRACTICE

Tripped Tripped

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

Reduce feed rate to

200 MMSCFD

NEW FLARE REDUCTION PRACTICE

Flaring Eliminated

200 MMSCFD to Running Train through Bi-directional Line

Tripped Tripped

IPTC 17273 15

Flare Reduction Scenario #3 - Restart after Cold Section Trip  This scenario involves restarting a train after a cold section trip. As listed previously in Table 4, each unit is designed with

a minimum turndown flow rate below which the gas acceptance specifications for the next unit will not be achieved. The approach to restarting the train in this scenario is to achieve the required specifications at the outlet of each unit while maintaining the desired minimum turndown rate with minimum flaring.

• Earlier Qatargas Practice:

§ Step 1: 250 MMSCFD* of feed gas introduced to Unit 02 and total amount directed to wet gas flare until sweet gas specification is reached. (*earlier minimum turndown recommended by process licensor)

§ Step 2: § When sweet gas from Unit 02 reaches specification, Unit 03 restarted followed by cool down of

Unit 04. § 600 MMSCFD required for cooling down Unit 04 (earlier rate recommended by process licensor)

and entire amount is lined up to dry gas flare in order to achieve lean gas specification at the outlet of Unit 04.

§ Once lean gas is available, Units 05 and 08 resume operation (these units were kept on standby during the trip).

§ Actual Event: Train 4 cold restart on 12 July 2011 - approximately 97 MMSCF flared**.

(**Represents total flaring volume over restart period only (< 1 day, total MMSCF and not MMSCFD). Does not include flaring from preceding trip.)

Figure 13: Mega-Train Flare Reduction – Cold Restart of Full Train

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

~250 MMSCFD flared

Reduce feed rate to

250 MMSCFD

EARLIER PRACTICE STEP (1)

Waiting for Sweet Gas Specification

Feed Gas

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

Ramp up feed rate to

600 MMSCFD

EARLIER PRACTICE STEP (2)

600 MMSCFD flared

Waiting for Lean Gas Specification

To DGF

16 IPTC 17273

Flare Reduction Scenario #3 - Restart after Cold Section Trip (Cont’d) • Flare Reduction Practice:

§ Step 1: 200 MMSCFD* introduced to Unit 02 and total amount diverted to other running train via bi-directional line which eliminates wet gas flaring (*new operational minimum turndown for Unit 02).

§ Step 2: § When sweet gas from Unit 02 reaches specification, feed rate ramped up from 200 to 450

MMSCFD (instead of earlier 600 MMSCFD) to restart Unit 04. § ≤ 250 MMSCFD of lean gas exported from Unit 04 to QP national grid. § Same lean gas also supplied to combined asset fuel system from tripped train (≤150 MMSCFD).

Fuel gas supply from other operating train minimized. § Flaring from Unit 04 reduced from 600 MMSCFD (earlier practice) to 50 MMSCFD.

§ Actual event: Train 5 cold restart on 14 September 2013 - approximately 40 MMSCF flared**.

(**Represents total flaring volume over restart period only (< 1 day, total MMSCF and not MMSCFD). Does not include flaring from preceding trip.)

Figure 14: Mega-Train Flare Reduction – Train Cold Restart

Feed Gas

To WGF

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

Reduce feed rate to

200 MMSCFD

FLARE REDUCTION PRACTICE STEP (1)

Waiting for Sweet Gas Specification

200 MMSCFD to Running Train through Bi-directional line

Flaring Eliminated

Feed Gas

V0201

[Unit 03 – Dehydration, Mercury and Mercaptans Removal]

V301A

V301B

V301C

V301D

-115 oC48.3 barg

[Units 05 & 06 - Chilling and Liquefaction]

2274 m3 /h 4.8 barg -159 oC

0.2 barg

-162 oC

LNG  product

C0801

A

[Unit 08 - N2 Rejection Unit]

ST EFG

-147 oC

HT0801

EFG  to  Fuel  Gas

K0401

C0401

Comp

K0402ST

[Unit 04 - NGL Recovery]

30 barg -71 oC

To  Unit  07  NGL  Fractionation

66 barg 35 oC

AGR Knockout

DrumDryer

ADryer

BDryer

CDryer

D

Mercury Removal

Bed

C3 Refrigerant

MR Refrigerant

N2 Refrigerant

N2 Rejection

Column

A

SteamTurbine EFG

HydraulicTurbine

Deethanizer

Expander

K0402SteamTurbine

Compressor

To DGF

LNG  

[Unit 02 - AGR]

AGR Absorber

Mai

n C

ryog

enic

Hea

t Exc

hang

er (

MC

HE

)

Sub

cool

erH

eat

Exc

hang

er (

SC

HE

)

Reduce feed rate to

450 MMSCFD

FLARE REDUCTION PRACTICE STEP (2)

~250 MMSCFD To QP

~150 MMSCFD to Fuel Gas

Reduced to ~50 MMSCFD

To DGF

IPTC 17273 17

Flare Reduction Pillar 3: Capital Projects As noted in Figures 3 and 4, the current major flaring sources at Qatargas’ LNG trains include jetty, baseline purge gas and

train and unit trips. The high volume of jetty flaring is common to all LNG trains, however, flaring from train and unit trips and purge is more significant at the mega-trains (as compared with QG1) due to their larger throughput and common flare system and cannot be reduced through operational means alone. An overview of the engineering projects currently being implemented by Qatargas to minimize these major flaring sources is provided in the sub-sections below.

Jetty BOG (JBOG) Recovery Project Qatargas is leading a major project to recover gas currently flared during LNG ship loading in Ras Laffan Port. The $1

billion JBOG Project is the largest project of its kind in Qatar and will enable BOG to be collected from LNG ships and compressed at a central facility. The compressed gas will then be sent to LNG producers to be consumed as fuel or converted back into LNG. The JBOG recovery process is outlined in Figure 15 below.

When fully operational in 2014, the JBOG Project is expected to recover more than 90% of gas currently flared at the six (6) berths or jetties in Ras Laffan Port, which are used by both Qatargas and RasGas for LNG export. This amounts to savings of approximately 0.6 MTA of LNG or the gas equivalent of 29 Billion Standard Cubic Feet (BSCF), which is enough natural gas to power 300,000 homes. In terms of GHG emissions, the above reduction equates to savings of approximately 1.6 million tonnes of CO2 per annum.

Figure 15: JBOG Project Overview

QG2, QG3&4 Purge Gas Reduction Project Qatargas conducted a Flare Reduction Feasibility Study in 2011 to identify technically feasible options for flare

minimization for the mega-trains. One of the most feasible and practical opportunities identified was purge gas reduction. While purge gas flows are an essential requirement to prevent air ingress into the flare system, their rate can be optimized through engineering analysis. Significant flare reduction can be realized with a relatively small investment and accelerated timeframe.

Current purge gas at the mega-trains comprises the following streams: • Header sweeping gas to prevent air ingress into the flare stack. • ‘Burn back’ gas: purge gas introduced at the flare stack to prevent burn back at the flare tip, thereby increasing tip

life. • Flame shaping gas for utility flare tips (sour gas flare) to facilitate proper combustion at the non-steam assisted flare

tips. Normal operation purge gas flows are calculated based on the American Petroleum Institute (API) Standard 521 (Ref. 6) to

provide less than 6% Oxygen (O2), 25 feet from the top of the flare tip. However, purge gas rates at the mega-trains maintained above API 521 guidelines to result in 1% O2, one meter below the flare tip in order to reduce burn back and increase tip life.

BOG collected by dedicated laterals (28-30”) to each of 6 berths

Main BOG header (60”)

TODAY - BOG from 6 QG and RG LNG berths flared

Central Compression Area • 2 compressor trains • Three 9 MW low, medium and high pressure compressors in each train • All compressors electrically powered • Each train = 82.5 t/h BOG recovery rate (total 163 t/h) • Pressure raised to 47 bar.

Qatargas and RasGas LNG Facilities • Recovered BOG used as fuel gas or converted to LNG

LNG Storage and Loading • LNG supply from producers to common tankage. • Rundown to 6 LNG berths for loading.

2014 – 90% recovered and reused* *Note: Depiction is for illustrative/indicative purposes only

18 IPTC 17273

The Mega-Train Purge Gas Reduction Project was initiated in 2012 to realize the following main objectives:

1. Reduction in purge rates to API 521 levels in two phases for a total projected reduction of more than 60% (from 2012 purge rates):

• Phase 1 – Dry Gas Flare #2 (DGF-2): A reduction of approximately 1.8 MMSCFD was realized in 2012 for QG2 DGF-2. A similar reduction is currently being progressed for QG3&4 DGF-2.

• Phase 2 – Dry Gas Flare #1 (DGF-1) and Wet Gas Flare (WGF): DGF-1 and WGF tips are both steam assisted. The project approach is to use the steam assisted tips and flare stack steam (center steam) for burn back protection rather than fuel gas. Header purge can then be reduced to API 521 levels*.

* No changes envisioned for sour gas flare due to its non-steam assisted flare tip and hazardous nature of sour gas.

2. Emergency Purge Gas:

• Installation of an emergency purge gas system on dry and wet gas stacks to address possible gas shrinkage after hot releases which may result in air ingress into the flare stacks.

• System will be initiated by 128 skin temperature sensors installed at 32 flare points around the mega-trains.

• Emergency purge flow will be triggered if the difference between flare point (skin) temperature and ambient temperature increases beyond a set limit.

The Purge Gas Reduction Project is expected to be operational within the 4th Quarter of 2013. QG2, QG3&4 Flare Reduction Project In addition to purge gas reduction, the Feasibility Study completed by Qatargas in 2011 also identified a range of longer-

term flare reduction opportunities for the mega-trains. These were further analyzed and shortlisted based on their technical feasibility, practicality and expected magnitude of flare reduction. A dedicated Flare Reduction Project was then initiated in 2013 to implement these opportunities. An overview of the identified opportunities with the highest flare reduction potential is provided in Table 5 below.

The Flare Reduction Project is currently in the Front End Engineering Design (FEED) phase and is tentatively expected to

become operational in the 4th Quarter of 2015.

Table 5: QG2, QG3&4 Flare Reduction Project - Main Opportunities Flare Reduction

Opportunity Scope of Work

Feed Gas Interconnection (Crossover)

• Interconnection available between Inlet Reception (IR) facilities for QG2 and QG3&4, provided for first start up of QG3&4.

• Existing interconnection can be used to avoid depressurization of offshore pipelines by flowing across the assets.

• Upgrade existing facilities for future requirement.

Off-spec Gas Recycle

• Recycle offspec gas from train under start-up to running train within same asset or mega-train in other asset.

• Majority of flaring takes place during train restart. • Existing bi-directional line available between Unit 02

(AGR) of each mega-train. Used for flare reduction in the event of hot section trip or full train restart.

• Upgrade existing bi-directional line to link Unit 03 (Dehydration, Mercury and Mercaptans Removal) and Unit 04 (NGL Recovery).

• Install new inter-asset header to recover across QG2 and QG3&4.

Fuel Gas Compressor (K801) End Flash Gas Interconnection and Recovery of Cool Down Gas

• Connect fuel gas compressor (K801) suction sides to recover End Flash Gas to compressor in other running train instead of flaring.

• Define requirement of pre-cool down, i.e., recovery of cool down gas from main cryogenic heat exchanger (MCHE) shell side to K801 fuel gas compressor.

QG2 IR Facilities QG3&4 IR Facilities

Existing bi-directional line New headers

QG2 LNG Train 5

Unit 2

Unit 3

Unit 4

QG2 LNG Train 4

Unit 2

Unit 3

Unit 4

QG3 LNG Train 6

Unit 4

Unit 3

Unit 2

QG4 LNG Train 7

Unit 4

Unit 3

Unit 2

QG2 LNG Train 5

QG2 LNG Train 4

Fuel Gas Compressor (K801) Suction

QG4 LNG Train 7

New interconnection

QG3 LNG Train 6

Fuel Gas Compressor (K801) Suction

Fuel Gas Compressor (K801) Suction

Fuel Gas Compressor (K801) Suction

IPTC 17273 19

Summary A summary of Qatargas’ engineering projects and their expected flare reductions and implementation timelines is provided

in Figure 16 below. Using 2012 flaring data as the baseline, the JBOG and Mega-Train Purge and Flare Reduction Projects, when implemented, are expected to reduce overall flaring by approximately 70%.

Figure 16: Summary of Qatargas Flare Reduction Projects Conclusion Despite numerous technical challenges as discussed in this paper, Qatargas has successfully reduced flaring at its LNG facilities in the range of 50-60% since 2009 through a combination of multi-disciplinary action (via asset FMTs), increased awareness, tracking and reporting, and most importantly, operational source reduction initiatives. Qatargas’ engineering projects which include the JBOG Project and Mega-Train Purge and Flare Reduction Projects are expected to further reduce current flaring by approximately 70%. Many challenges still exist with respect to flare minimization at Qatargas. These include the successful completion of the flare reduction engineering projects described in this paper, changing regulatory dynamics with more stringent requirements for flare minimization, and maintaining internal awareness and focus on flare management, setting and meeting aggressive, yet practical, flaring targets. Upcoming focus areas will also include improvement in flare meter reliability and availability, minimization of small flaring sources such as passing valves through implementation of a valve monitoring program (using an acoustic meter), continued optimization of operational procedures to reduce flaring, and finally, development and implementation of a comprehensive Flare Management Program with specific, standardized policies and procedures. References 1. State of Qatar General Secretariat for Development Planning. “Qatar National Vision 2030”. Policy Document. July 2008. 2. State of Qatar General Secretariat for Development Planning. “Qatar National Development Strategy 2011-2016”. Policy Document.

March 2011. 3. Qatargas Operating Company Limited. “Sustainability Report 2012”. Annual Report. Published 2013. 4. Qatargas Operating Company Limited. “Sustainability Report 2011”. Annual Report. Published 2012. 5. Qatargas Operating Company Limited. “Corporate Citizenship Report 2010”. Annual Report. Published 2011. 6. American Petroleum Institute (API). “Standard 521: Petroleum and Natural Gas Industries, Pressure-Relieving and Depressuring

Systems”. Standards Document. Addendum May 2008. Acknowledgment • Raja, M.: “Qatargas Flare Management – Challenges and Achievements”, presentation at IQPC Flare Management and Reduction

Summit, Abu Dhabi, UAE, 14-17 October, 2012.

100%

93%

62%

30%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2012  Baseline 4Q  2013 2Q  2014 4Q  2015

Flaring  as  %  of    20

12  Baseline

2012  Baseline(All QG  Trains,  incl.  jetty  flaring)

QG2,  QG3&4  Purge  Gas  Reduction  Project(Flare  Volume  Reduction  ~7%)

JBOG  Project  Start-­‐up(Flare  Volume  Reduction  ~31%)

QG2,  QG3&4  Flare  Reduction  Project1.  Feed  Gas  Interconnection  (Crossover)2.  Offspec  Gas  Recycle3.  Fuel  Gas  Compressor  (K801)  End  Flash  Gas  Interconnection4.  Recovery  of  Cool  Down  Gas

(Total  Flare  Volume  Reduction  ~31%)

Notes:1.  Data  shown  above  is  for  illustrative  purposes  only  and  based  on  currently  expected  flare  reductions  and  timelines. These  are  subject  to  change  once  the  various  initiatives  are  implemented  in  the  field.  2.  2012  baseline  reflects  flaring  data  until  Dec  31,  2012,  including  jetty  flaring.  3.  JBOG  Project  is  common  facility  catering  to  all  QG  LNG  assets  (incl.  QG1)  and  RasGas.  Data  shown  is  in  context  of  flare  reduction  at  QG2  and  QG3&4  mega-­‐trains  only.