Slide 1

Vapor Recovery in Offshore ApplicationsGulf Coast Regulatory and Environmental Affairs Group MeetingJuly 11, 2013Air Quality Regulations

BOEM/BSEE has jurisdiction for Western/Central Gulf of Mexico air quality for oil and gas drilling and production operations.East of 87.5 degrees longitude jurisdiction of OCS waters is USEPA Region 4. States have jurisdiction for air quality for onshore and coastal/territorial seas. Texas territorial waters (and county line) extend for three marine leagues (10.36 statute miles) offshore Texas

VRU Drivers Onshore/Coastal Areas

May need vapor recovery to meet state permitting rules or federal standard that apply to onshore, coastal and territorial seas. Limits flash gas to meet permit limits in general permits (Louisiana) or permit-by-rule (PBR) permits (Texas) Normally an option for permits, not always mandated. Option used to meet control requirements for storage tanks in 40 CFR 60 Subpart OOOO New Source Performance Standard - Oil and Natural Gas Sector

VRU Drivers Western/Central GOM

30 CFR 250.1160 When may I flare or vent gas?(a)(5) You may not flare or vent more than an average of 50 MCF per day during any calendar month without Regional Supervisor approval. Limit of 50,000 SCFD average flash gas vent/flare gas limit (30 CFR 250.1160). Recover flash gas if economical to recover gas

VRU Drivers Western/Central GOM

30 CFR 250.1160 When may I flare or vent gas?(b) states that must not flare or vent gas over the volume approved in your Development Operations Coordination Document (DOCD) or in Development and Production Plan (DPP) submitted to BOEM.Typically this volume is in the Air Quality Review (AQR) spreadsheets submitted with DOCDTypical Production Process

Must be something generally accepted by industry and regulators. Options include: Direct measurement of tank vent Collect/analyze pressurized oil and measure gas to oil ratio (GOR)Pressurized oil sample/analyses as input to Equations of State computer simulation or API E&P Tank computer pgm.

Tank Vent Gas Quantification

Data collection (Direct Measurement)

IQR Process Measurement ProtocolSimple & easy way to measure volume of vent gas with 98% accuracyFlow characteristics identified(very cyclical)Gas composition analyzed

Why Vapor Recovery?

Regulatory complianceRecover very rich flash gas - $$Reduce emissions of VOCs and greenhouse gasesImprove safety of facilities

Engineered Solution Design

Volume & peaks of flowComposition(s) of gas. H2S?PressuresTemperaturesAvailability of utilities (power/motive gas)Availability of booster compressionMarkets for products

Types of Solution Package Technologies

Traditional vapor recovery uses compressors driven by electric or natural gas enginesReciprocating compressorsRotary screw compressorsRotary vane compressorsScroll compressorsEjector Vapor Recovery Unit (EVRU)

Reciprocating Compressors

High pressure & volumes Automatic bypass (recycle)Not recommended for wet gas

Flooded Screw Compressors

High pressure differentialsHigh volume capacitiesVariable Frequency Drive (VFD)Oil dilution issues

Rotary Vane Compressors

High volume capacitiesVFD or bypassNo oil dilutionLow pressure differentials 60 psig in single stageVane wear

Scroll Compression

Less moving partsLess maintenanceVFDOil dilution issues20 ppm H2S limit

Application of Scroll Technology

Recovering gas from oil storage tanks and heater treater and discharging pressurized gas to larger compressor VRU system requires electrical power and purge gas for recycleHigh molecular weight gas recovery

Scroll Compressor Case Example

Dual CVRU package for Offshore ApplicationDesign criteriaRecovered gas throughput: 150,000 SCFD (150 MSCFD) Vent gas source: atmospheric storage tanksSuction Pressure: 1 to 3 inches water column Discharge Pressure: 100 psigDischarge to suction of onsite larger compressor

Offshore Scroll System

SPE-127153-PP Paper Conclusions

Recovers natural gas product Lowers emissions of VOCs and GHGs Lower maintenance costs than typical VRUs System requires smaller footprint Cost effective and efficient VRU for offshore environment

COMM Patented EVRU

MotiveSuctionDischarge$$$$$$$$$

EVRU Case Study Economics

Investment: $120,000 700 BOPD of 62 API Gravity Average gas recovery: 175 MCFD $709,560/year product recovery at $6/MMBTU Payback period: 2 months

EVRUOffshore AfricaEagle Ford Onshore

Offshore GOM EVRU

EVRU System Advantages

Simple, non-mechanical vapor recovery system 100% run time and on/off provides turndown Handles rich, wet gas & H2S No oil to maintain Small footprint Easy to modify Texas allows emission control efficiency of 99%

Key Points for a VRU Solution

Determine regulatory requirements Value of natural gas recovered Cost of VRU capital costs and operation costs Knowing facility process and gas to be recovered critical to design and effective operation of VRUMeasure & sample gas if possibleConsider redundancy or easy replacement options

1319 West Pinhook RoadLafayette, Louisiana USABrian BoyerSalah Mansour(337) 237-4373www.commengineering.com