BACKGROUND FOR NEPA REVIEWERS: CRUDE OIL AND NATURAL GAS EXPLORATION, DEVELOPMENT, AND PRODUCTION Submittedto: U.S. EnvironmentalProtectionAgency Office of Solid Waste SpecialWasteBranch Crystal station 2800 Crystal Drive Crystal City, VA 20202 Submittedby: ScienceApplicationsInternationalCorporation EnvironmentalandHealth SciencesGroup 7600-A LeesburgPike Falls Church, VA 22043 DISCLAIMER AND ACKNOWLEDGEMENTS The mentionof companyor productnamesis not to be consideredan endorsementby the U.S. Governmentor by the U.S. Environmental ProtectionAgency(EPA). This documentwas preparedby Science ApplicationsInternationalCorporation(SAIC) in partial fulfillment of EPA Contract Number68-W0-0025,Work Assignment61. BACKGROUNDFOR NEPAREVIEWERS TABLE OF CONTENTS Page INTRODUCTION ................................................. 1 OVERVIEW OF OIL AND GAS EXPLORATION AND PRODUCTION .......... 1 STATUTORY AND REGULATORY BACKGROUND..................... 1 Leasingon FederalLands ................................... 4 SafeDrinking Water Act ................................... 7 CleanWater Act ......................................... 8 Clean Air Act (CAA) ..................................... 9 ResourceConservationand RecoveryAct ......................... 10 TECHNICAL DESCRIPTIONOF EXPLORATION AND PRODUCTION OPERATIONS .................................... 12 EXPLORATION AND DEVELOPMENT. ............................. 12 Road Constructionand Maintenance ............................ 12 Preliminary Exploration .................................... 12 Well Drilling ........................................... 14 Drilling Fluids ..................................... 17 Drilling Fluid Wastes................................. 18 FormationEvaluation ................................. 19 Well Completion ........................................ 19 CompletionWastes .................................. 21 Well Stimulation. ........................................ 21 StimulationWastes .................................. 22 Well Abandonment ....................................... 22 AbandonmentWastes................................. 22 OIL AND GAS PRODUCTION .................................... 23 Field Design ........................................... 23 Recovery ............................................. 23 ProductCollection (Gathering) ................................ 24 ProducedFluid Treatment ................................... 25 Two-phase Separator................................. 25 Three-phaseSeparator ................................ 25 Free-WaterKnockout ................................. 27 Heater Treater.. ................................... 27 GasDehydration. ................................... 27 Sweetening/SulfurRecovery ............................ 27 Natural GasLiquids Recovery ........................... 28 Compression ...................................... 28 Skimming Pit...................................... 28 SolidsRemoval .................................... 29 Produced Water.................................... 29 Waste Management....................................... 30 Explorationand ProductionWastes ........................ 30 Reserve Pits...................................... 31 June 15, 1992 DRAFT OIL AND GAS Annular Disposalof Drilling Wastes ....................... 32 Centralized Disposal Pits.............................. 32 Drilling WasteMinimization ............................ 32 Storage,Settling, and SkimmingPits and Tanks ................ 33 UndergroundInjection ................................ 33 Dischargeof ProducedWatersto SurfaceWater ................ 34 Evaporationand PercolationPits .......................... 34 Land Farming ..................................... 34 SurfaceSpreadingof ProducedWaters ...................... 34 Use of ProducedWater for Irrigation ....................... 34 CentralTreatmentFacilities ............................. 35 Crude Oil Reclaimers................................. 35 RoadBuilding Materials ............................... 35 CasingVent GasRecovery ............................. 35 Gas Flares ....................................... 36 Miscellaneousand NonexemptOil Field Wastes ................ 36 Site Closure ........................................... 36 COALBED METHANE DEVELOPMENT ............................. 36 Nature of the Resource..................................... 37 Typesof CoalbedDevelopmentProjects .......................... 37 Vertical DegasificationWells in Advanceof Mining .............. 38 Horizontal DegasificationWells .......................... 38 Gob GasWells ..................................... 38 Vertical GasWells Independentof Mining .................... 38 CoalbedMethaneWell Drilling and Completion ..................... 38 CoalbedMethaneWell Stimulation ............................. 39 CoalbedMethaneProduction ................................. 40 CoalbedMethaneWasteManagement ........................... 41 POTENTIAL SIGNIFICANT ENVIRONMENTAL IMPACTS ..................... 42 POTENTIAL IMPACTS ON GROUND WATER ......................... 42 Exploratory and DevelopmentDrilling ........................... 42 Vertical Migration of Contaminants........................ 43 Ground-waterDrawdown .............................. 43 Production ........................................... 43 Migration of Stimulation Fluid to Ground Water.............. 43 Damageand Blowout of Existing Wells ................... 43 Migration of Injected Water to Ground Water............... 44 Migration of Steamand Other InjectedSolutionsto Ground Water ... 44 PotentialDamagesfrom In-situ Combustion................. 44 Migration of GatheringLine Spills to Ground Water ........... 44 Product Stock Tank Leakage.......................... 44 Waste Management.. .................................. 46 Migration of Deep Well Injected Fluids................... 46 Migration of Annular Injected Fluids.................... 46 Migration of SweeteningWastes ...................... 46 Vertical Migration from SurfaceTreatmentSites ............ 47 June 15, 1992 DRAFT BACKGROUNDFOR NEPA REVIEWERS Site Closure ........................................... 47 Vertical Migration of ClosedPit Contentsto GroundWater ......... 47 POTENTIAL IMPACTS ON SURFACEWATER ........................ 47 Explorationand Development ................................ 47 Site Runoff to SurfaceWaters ........................... 47 Production ............................................ 48 Migration of ProductStockTank Leaks ..................... 48 Migration of GatheringLine Leaks ......................... 48 Vertical Migration of Injection Fluids ....................... 48 WasteManagement....................................... 48 SurfaceWater Dischargesof Reduced Water .................. 48 Migration of CommingledWastes .......................... 49 Runoff from SurfaceTreatmentSites ....................... 49 Migration of SweeteningWastes .......................... 49 Site Closure ........................................... 49 Sedimentationof SurfaceWaters .......................... 49 POTENTIAL IMPACTS ON SOIL .................................. 49 Exploration and Development ................................ 50 Compactionand Erosionfrom RoadBuilding ................... 50 Site Runoff ....................................... 50 Production ............................................ 50 Compactionand ErosionDuring Production................... 50 ProductStockTank Leaks .............................. 50 Gathering Line Leaks................................. 50 Injection Fluids and SaltwaterBreakout ..................... 50 WasteManagement....................................... 51 Pit Excavation,Overtoppingand Seepage .................... 51 SweeteningWastes .................................. 51 Onsite Burial of Pit Wastes............................. 51 Landfarmingof Pit Wastes ............................. 51 Evaporationof ProducedWater .......................... 52 Site Closure ........................................... 52 Sedimentationof SurfaceWatersfrom Site Runoff. .............. 52 POTENTIAL IMPACTS ON AIR .................................... 52 Explorationand DevelopmentDrilling ........................... 52 HydrogenSulfide Emissionsfrom Active Operations ........... 52 Fugitive Dust Emissions.............................. 52 MachineryExhaustEmissions ......................... 53 Production ........................................... 53 Emissions from Gas Flaring .......................... 53 Volatilization of PetroleumFractions ..................... 53 Releaseof HydrogenSulfide from Sour Gas ................ 53 MachineryExhaustEmissions .......................... 53 WasteManagement..................................... 53 Volatilization During Evaporationand Landfarming ........... 53 June 15, 1992 DRAFT OIL AND GAS POTENTIAL IMPACTS ON ECOSYSTEMS ............................ 54 Abiotic EcosystemParameters................................ 54 Temperature ....................................... 54 Water .......................................... 54 Nutrients ........................................ 55 Topography....................................... 56 Soils ........................................... 56 Light ........................................... 56 Flushingof Aquatic Ecosystems.......................... 56 Salinity ......................................... 56 Turbidity andSuspendedSediments......... .............. 57 Biotic EcosystemParameters................................. 57 Rare and EndangeredSpecies...........................