Fugitive emissions are unintended releases of gases from industrial equipment like pumps, compressors, and valves. This document discusses strategies for reducing fugitive emissions from oil and gas operations at the Jubilee Field in Ghana. It recommends developing a leak detection and repair program to monitor equipment for leaks. Selecting appropriate seals for equipment and following a direct inspection and maintenance process can minimize emissions. While flaring at the FPSO exceeds limits, substituting nitrile seals could help reduce emissions cost-effectively. Overall, a long-term commitment is needed using regulations, alternative energy, and improved management practices to significantly cut fugitive emissions.
1. HANDLING FUGITIVE EMISSIONS AT THE JUBILEE
FIELD: SELECTING THE RIGHT SEALS AND OTHER
ALTERNATIVES
PRSENTED BY:
HERMINIA NCHAMA ELA
BRUKUM DANIEL
SUPERVISOR:
MR. ABDUL HAMEED MUSTAPHA
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3. OBJECTIVES
To know the potential breakdown of hydrocarbons related fugitive emissions in the
world
To know how and why fugitive emissions occur
Detecting and monitoring fugitive emissions
To determine the current inventory methodologies for quantifying fugitive emissions
Selection of the right seals in reducing spurious emissions
Other alternatives for controlling and minimizing fugitive emissions
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4. PROBLEM STATEMENT
FE
Green house effects
which leads to a
phenomenon called
global warming
resulting in climate
change
Health hazards
caused by air
pollution
Economic loss
of commodities
Risks of fire and
accidents
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5. INTRODUCTION
Fugitive emissions are emissions of gases and vapours from pressurised equipment due to
leaks and other unintended or irregular release of gases, mostly from industrial activities.
Sources of FE in the oil and gas industry include process equipment leaks, evaporation and
flashing losses, venting and flaring and accidental releases.
Process equipment components that are sources of FE through leaks include Pumps,
Compressors, Valves, Pressure relief valves and Pipe connections
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6. Global concern for FE
IEA in 2009 predicted that the world’s total energy demand will grow by 35% in the year 2030
higher.
Energy sector being the highest contributor to emissions.
Oil and natural gas industry expected to account for nearly 60%.
Thus FE must be minimized in order to address the global climate change challenge.
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7. The Jubilee Field
The FPSO can produce up to 120 M BOPD, 120 MMSCFD, storage capacity of 1.6
MM barrels of oil and injects 230 MM barrels of water a day.
Government of Ghana has a ‘zero flaring’ policy at the FPSO.
Out of the 120 units of gas produced per day, 20 are used to power the engines on the
FPSO, 30 used for well injection and 70 are flared or vented.
Stack and FE campaign carried out to evaluate emission levels from the Gas Turbine
Generators (GTGs), Emergency boilers and the Side Port Crane.
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8. Detection of FE
A variety of approaches are used for leak detection:
1. Soap solutions
2. Odorants
3. Portable analyzers
4. Static Leak Indicators; bag and streamer, color indicating tape, chronic leak
monitoring
5. Electronic Screening Devices; gas monitors, ultrasonic leak detectors, laser or
infrared detectors.
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9. METHODOLOGY
Emission inventory prepared to estimate the quantities of FE released from a facility.
Two guidelines that are applicable worldwide are:
1. The US EPA – API Assessment
2. The Intergovernmental Panel on Climate Change (IPCC) Assessment
The USA EPA-API Assessment is based on four methods:
Method 1. Average Emission factor method
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10. Cont. of Emission inventory methodology
Method 2. The Screening Value Range Method10
11. Cont. of Emission inventory methodology
Method 3. Correlation Equation Method
Method 4. Unit-specific Correlation Equation Method
Particular sets of individual equipment components are selected for screening for
which screening and actual mass emissions are measured directly from.
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12. Key challenges during the assessment of FE
The identification of sources
Measurement of FE
Return on investment
Lack of public engagement
Technology
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13. Sealing system
Seals are devices installed in process equipment to isolate the fluid medium from being
released into the atmosphere during the operation of the process equipment. Process
equipment are normally under pressure.
Pump seals: They are used to mitigate leakages between the moving shaft and the
stationary housing. E.g., Packing and Mechanical seals
Compressors seals: They are usually equipped with ports in the seal area to evacuate
gases that maybe accumulated there. E.g.., Labyrinth and Mechanical contact seals
Valves: They are activated by a valve stem. E.g., Packing, Elastomeric O-rings and
Bellow seals
Flanges: They are bolted, gasket-sealed junctions between sections of pipe and pieces of
equipment.
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14. SELECTION OF THE RIGHT SEAL
Seal selection can be based on the fluid’s specific gravity and the maximum allowable
VOC emission levels
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15. Selection factors for seals in the oil and gas industry
Temperature: The temperature of the fluid contacting the seal. Temperature data
will limit the number of viable seals for an application.
Application: Knowing how the seal is to be used and function it is expected to
perform. E.g., selection of compression packing depends on the condition of the
stem whether its motion is reciprocating or helical (insufficient loading)
Medium: Sensitivity of the media to the seal (compatibility)
Pressure: Internal pressure a seal must contain.
Size: Conforming to standards such as AMSE, API, ANSI
Speed: High speeds call for sealing materials that can withstand and effectively
dissipate frictional heat
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16. Other improved alternatives for detecting and
measuring FE
Direct Inspection Absorption of Light (DIAL) can be used to remotely measure
concentration profiles of hydrocarbons in the atmosphere up to several hundred meters from
the facility.
Optical Gas Imaging(OGI) operates much like a consumer video-camcorder and provides a
real-time visual image of gas emissions or leaks to the atmosphere.
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18. Leak Detection and Repair (LDAR) Program
1. Determine which equipment leak regulations are applicable
2. Understand the overall approach of using both equipment standards and leak detection
and repair standards
3. Determine if source complies with all the requirements of component identification,
marking, monitoring repair, record keeping and reporting.
4. Evaluate source personnel’s calibration procedures and records
5. Evaluate field monitoring procedures used by source personnel to detect leaks from
components
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19. Leak repair and Economic Analysis
𝑃𝐵𝑃 =
𝐸𝑠𝑡𝑖𝑚𝑎𝑡𝑒𝑑 𝑟𝑒𝑝𝑎𝑖𝑟 𝑐𝑜𝑠𝑡
𝐿𝑒𝑎𝑘 𝑟𝑎𝑡𝑒+𝑛𝑒𝑡 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑙𝑜𝑠𝑡 𝑔𝑎𝑠
Where;
PBP = Pay Back Period (years)
Estimated repair cost or Cost of control = direct repair or replacement costs + gas vented
during repair + cost of lost production due to shutdown ($).
Annual Leak Rate or Leak Rate = amount of gas/vapour emitted directly to the atmosphere
or that leaked into a vent or flare system which does not have vent or flare gas recovery
(m3/year).
Net Value of Lost Gas or Gas Price = current market price of the gas based on criteria
specified by the midstream industry, processing fee or margin received ($/103m3).
In the case where the leak repair has a payback of less than a one year, it is economical to
repair and must be repaired as soon as possible.
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20. Sample calculation of a payback period for individual repairs
Tag
ID
Component
type
Nominal
size
Stream
type
Hydrocarbons
leak
rate(m3/hr.)
Hydrocarbons
leak
rate(103m3/yr.)
Net
value
lost
$/103m3
Estimated
repair
cost($)
PBP
1991 Gate Valve 8 Wet
Gas
0.0046 0.0407 149.60 353 58.0
1992 Flange 8 Wet
Gas
0.0026 0.0228 149.60 100 29.3
1993 Ball Valve 0.5 Wet
Gas
0.0028 0.0241 149.60 60 16.6
1995 Gate Valve 8 Wet
Gas
0.0090 0.0785 149.60 353 30.1
1996 Gate Valve 8 Wet
Gas
0.0015 0.0129 149.60 353 182.9
1997 Flange 8 Wet
Gas
0.0036 0.0313 149.60 100 21.4
1998 3-Way
Control
valve
8 Wet
Gas
0.0021 0.0187 149.60 350 125.1
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21. Flaring at the FPSO in the Jubilee Field
0
10
20
30
40
50
60
Percentage of flared volumes to total produced gas volumes at the Jubilee Field
2011 2012 2013 2014
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22. LIMITATION
The oil and gas industry is very diverse and complex making it difficult to ensure
complete and accurate results for FE quantification.
Lack of data to compute the emission inventory of FE
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23. CONCLUSION
The challenge of reducing FE will require a long-term planning and steadfast
commitments.
The amounts of flared volumes at the FPSO in the Jubilee Field exceeds the limit set
out for the Jubilee Operator.
The best seal material to be used on the FPSO is Nitrile. This is because:
I. It combines excellent resistance to hydrocarbon based fluids.
II. It has a good working balance properties.
The drawing out of a comprehensive DI&M and or LDAR program to be
implemented at the FPSO will;
I. Increase revenue to TGL through the reduction in the loss of sealable, valuable fluids.
II. Significantly contribute to the improvement of air quality in the immediate environs of
the FPSO as well as to residential communities onshore
III. Improve maintenance routine and help TGL comply with environmental laws of the
country and the world in a whole.
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24. Recommendation and further work
Stipulation and enforcement of regulations to reduce fugitive emissions
released from process equipment and other sources at oil and gas industries.
Increase the development of alternative energy.
Improving good management practice by including technology development
and deployment.
Jubilee Field Partners are called upon to develop a comprehensive fugitive
emission inventory program and the elaboration of Emission Factors when
developing their annual GHG emission inventory. GH EPA must regulate this
campaign.
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