More Related Content Similar to Lnapl Tn For Tceq Tf 2010 100504 Sec 1to3 (20) Lnapl Tn For Tceq Tf 2010 100504 Sec 1to32. Acknowledgements Andrew Kirkman - AECOM Mark Adamski - BP Tim Smith - Chevron Charles Stone - TCEQ Roger Rinas - Valero Dr. Charbeneau - UT Dr. Huntley - SDSU Dr. Sale - CSU Introduction ©2010 by H2A Environmental, Ltd., All Rights Reserved 3. Questions Tn Can Answer Understanding What is the best way to quantify mobile LNAPL impacts? How can I do this cost-effectively? Comparison I have 10 ft of diesel and 2 ft of neat toluene – How can I compare them? Which one is more likely to migrate? How much more likely? Which one will I be able to pump the most LNAPL from? Which one will operate longer? Prediction How many bbls/gals will each well produce? How long will my recovery last? What remediation technology will be most effective/efficient? Management I manage 300 sites with LNAPL – How do I rank and prioritize potential migration risk and recovery potential? I’ve been pumping water and LNAPL for years; Can I quit? When can I quit? Introduction ©2010 by H2A Environmental, Ltd., All Rights Reserved 4. Analogs Hydrogeology Aquifer Testing yields K and T for water movement / production Pumping Tests and Slug Tests Normalizes all sites to one measurement standard to: Analyze – Compare – Predict – Design Multiphase Fluid Mechanics Multiphase Saturation Distributions add Complexity Different Fluid Properties Result in Different Flow Characteristics Relative Permeabilities - Fluids Compete for Pore Space Result: Generally Inhibited LNAPL Flow Petroleum Engineering Production Decline Curve Analysis Rate Transient Analysis (RTA) Expected Ultimate Recovery (EUR) Analysis Introduction ©2010 by H2A Environmental, Ltd., All Rights Reserved 5. Outline LNAPL Metrics for Hydraulic Recovery LNAPL Transmissivity (Tn) Definition Determination Applicability Limitations Tn and TRRP NAPL Mgmt Responses TRRP-32 Endpoints Remediation Design Operational Performance Examples (Not in Handout) Introduction ©2010 by H2A Environmental, Ltd., All Rights Reserved 7. Decision Point - a Metric at which a change is made (e.g., de minimis liquid recovery so convert from MPE to SVE).End Point - a Decision Point at which an activity ceases (e.g., risk-based cleanup levels attained so remediation stops). Metrics, Decision Points and End Points are captured in tables and flow charts in the TRRP-32 NAPL Management guide. ©2010 by H2A Environmental, Ltd., All Rights Reserved 8. Ideal LNAPL Metric Collective Property incorporates physical & chemical properties of the aquifer & LNAPL (e.g., permeability, viscosity) Incorporates LNAPL Type (benzene vs. bunker oil) Incorporates aquifer type (sand vs. clay) Fundamental or Characteristic Property Repeatable for given conditions Saturation / Mass Driven Multiphase saturation distribution Varies directly with LNAPL mass Easily Measured Supported with multiple lines of evidence Obtained prior to or during remediation Metrics for Hydraulic Recovery ©2010 by H2A Environmental, Ltd., All Rights Reserved 10. Same mass exhibits different thicknesses in different soil typesMetrics for Hydraulic Recovery Modified after Kirkman (2009) ©2010 by H2A Environmental, Ltd., All Rights Reserved 15. Can’t be used to predict performance prior to startup©2010 by H2A Environmental, Ltd., All Rights Reserved 16. Tn – An Improved Metric Can be easily determined prior to, during and after remediation Comparable across soil types Comparable across LNAPL types Comparable across Technologies Comparable across unconfined, confined and perched conditions Must understand LCSM Must calculate drawdown correctly Comparable between sites Varies directly with LNAPL saturation / mass Measures hydraulic recovery Metrics for Hydraulic Recovery ©2010 by H2A Environmental, Ltd., All Rights Reserved 17. Section 2 Section Break LNAPL Transmissivity (Tn) Definition Determination Applicability Limitations ©2010 by H2A Environmental, Ltd., All Rights Reserved 18. Tn Definition Transmissivity (T) for water is the volume of water flowing through a cross-sectional area of an aquifer that is 1 foot wide X the thickness of the aquifer (b), under a hydraulic gradient of 1 ft/ft, in a given amount of time (e.g., 1 day) LNAPL Transmissivity (Tn) is the volume of LNAPL flowing through a cross-sectional area of an aquifer that is 1 foot wide X the thickness of the mobile LNAPL interval in the aquifer (bn), under a hydraulic gradient of 1 ft/ft in a given amount of time (e.g., 1 day) Transmissivity (Tn) ©2010 by H2A Environmental, Ltd., All Rights Reserved 23. ASTM (2010) Under Development©2010 by H2A Environmental, Ltd., All Rights Reserved 24. Baildown Testing Transmissivity (Tn) Drawdown Calc (>0.5 feet) Confined / Unconfined Perched Field Methods Remove Borehole Volume Minimize CGWS Disturbance Boundary Conditions Analytical Options Bouwer & Rice Discharge-based Methods 1/Q, s/Q, SSR ©2010 by H2A Environmental, Ltd., All Rights Reserved 25. Manual Skimming Testing Basis – Skimming Recovery Equation Field Methods Remove Borehole Volume Repeatedly Establish Sustainable NAPL Discharge Minimize CGWS Disturbance Applicability <0.5 Feet or Rapid Recharge Minimizes Gauging Errors Equation: Transmissivity (Tn) ©2010 by H2A Environmental, Ltd., All Rights Reserved 26. Recovery Data Analysis Transmissivity (Tn) NAPL only Removal Skimming Vacuum-Enhanced NAPL Removal Vacuum-Enhanced Skimming Water-Enhanced NAPL Removal Total Fluids Pumping (Single or Dual Pump) Water & Vacuum-Enhanced NAPL Removal MPE ©2010 by H2A Environmental, Ltd., All Rights Reserved 27. Skimming (NAPL Only Removal) Considerations Adjust for bn changes ln(Roi / rw) estimated at 4.6 bn(1-ρr) is max drawdown If operating at less than max drawdown, use Qn and operating drawdown Equation (Charbeneau 2007) Transmissivity (Tn) IDEAL PUMP DEPTH NON-IDEAL PUMP DEPTH ©2010 by H2A Environmental, Ltd., All Rights Reserved 28. Vacuum-Enhanced Skimming Considerations If RaI not known, estimate RaI via Charbeneau (2007) equation – be careful in layered stratigraphy 1st equation uses air flow and open screen to calculate vac influence 2nd equation uses vacuum and ln(RaI / rw) to calculate vac influence Equations (Charbeneau 2007) Transmissivity (Tn) ©2010 by H2A Environmental, Ltd., All Rights Reserved 29. Water-Enhanced NAPL Removal Total Fluids Pumping Single or dual pump Considerations Simple Form (1st Equation) assumes swater is much greater than sn If any doubt, use 2nd Equation Equations Charbeneau (2007) Transmissivity (Tn) ©2010 by H2A Environmental, Ltd., All Rights Reserved 30. Water & Vac-Enh NAPL Removal MPE – DPE or TPE Considerations If RaI not known from pilot testing/operation, estimate RaI as in VES Air flow or Vacuum/RaI options similar to VES Equations (derived from Charbeneau 2007) Transmissivity (Tn) Kirkman (2009) Hawthorne (2010) ©2010 by H2A Environmental, Ltd., All Rights Reserved 31. Physical Properties / Modeling Laboratory Analyses NAPL Saturation Grain-Size Analysis Capillary Pressure Curves Core Photography and others Modeling LDRM Input/Calibration Points Kw / Tw / Tn / vG parameters Saturation Recovery Data Outputs Daily and Cumulative Recovery Saturation Profiles Specific / Recoverable Volumes Tn thru Time Transmissivity (Tn) Capillary Pressure Curve ©2010 by H2A Environmental, Ltd., All Rights Reserved 32. Tracer Testing Transmissivity (Tn) Developmental Stage Concerns Localized Qf but large scale NAPL gradient Uncertain Well Convergence Factor Initially Capital Intensive (Sale et al 2007) ©2010 by H2A Environmental, Ltd., All Rights Reserved 33. Tracer Testing (Tim Smith, Chevron, 2010) Transmissivity (Tn) Field Test Tracer Concentrations(UV/VIS spectrometer ) Gradient LNAPL Thickness Well Construction Analytical Options Calculate LNAPL flux through well Calculate LNAPL flux through formation Calculate Tn Where: Ct = Tracer concentration at time Dt (M/L3) Co = Initial Tracer concentration (M/L3) qwL = LNAPL flux through well (L/T) Dt = change in time between measurements (T) D = diameter of well (L) bL = continuous thickness of LNAPL in the formation (L) iL = LNAPL gradient (L/L) a = flow convergence factor (L/L) qfL = LNAPL flux in the formation (L/T) TL = LNAPL Transmissivity (L2/T) ©2010 by H2A Environmental, Ltd., All Rights Reserved 34. Applicability – Uses for Tn Inexpensive, numeric alternative to laboratory NAPL saturations Calibration Parameter for multiphase model API / Dr. Charbeneau – LNAPL Distribution and Recovery Model (LDRM) Calibrate to initial pre-remediation Tn values (and other site data) Calibrated Model Provides Predicted Values for: Tn and specific/recoverable volumes over recovery time Technology-specific recovery curves for LNAPL – rate and total volume estimates LNAPL/water saturations through time versus residual/irreducible saturations LNAPL thickness profile over time Drawdown profile Remediation Design Parameter Operational Progress Metric End or Decision Point for Hydraulic Recoverability – 0.3 to 0.8 ft2/day Technical Impracticability Threshold for Hydraulic Recovery Transmissivity (Tn) - Design ©2010 by H2A Environmental, Ltd., All Rights Reserved 35. Applicability - Scale Individual Wells Increased Precision Reduced Area of Relevance Collective Recovery Data Decreased Precision Travel Time Considerations Interlocked Network Interception / Capture Barrier Increased Area of Relevance Scale of Measurement Match to Scale of Recovery Transmissivity (Tn) t3 t2 t1 ©2010 by H2A Environmental, Ltd., All Rights Reserved 40. Tn does NOT address dissolved or vapor phase risk-based drivers 41. Tn measures recoverable, not residual or total LNAPL, and therefore measures progress towards soilresTransmissivity (Tn) ©2010 by H2A Environmental, Ltd., All Rights Reserved 42. Section 3 Section Break Tn and TRRP NAPL Mgmt Responses TRRP-32 Applicability Decision Points Remediation Design Operational Performance ©2010 by H2A Environmental, Ltd., All Rights Reserved 43. TRRP-32 NAPL Management Tn and TRRP Five (5) Step Process TRRP-12A Trigger Identification Response Objectives / Endpoints Design Phase (SIN / RAP) Implementation / Evaluation ©2010 by H2A Environmental, Ltd., All Rights Reserved 45. NAPL Response Endpoint Types ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 3 NAPL Response Endpoint Types Recovery Control Recovery Only Control via TI 46. NAPL Response Endpoint Matrix(Migrating NAPL Zone Trigger) ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 3 Nat. Control -NSZD 47. NAPL Response Endpoint Matrix(NAPL Contact with GW Trigger) ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 3 Alt. Tech – NSZD? 48. TI Demonstration ©2010 by H2A Environmental, Ltd., All Rights Reserved RECOVERY ONLY If Conventional & Alternative Technologies Cannot Achieve Endpoint. RECOVERY If Inability to File an Institutional Control Forces Site into Recovery and Conventional and Alternative Technologies Cannot Achieve Endpoint. Requirements Tool B - Qualitative Screen for TI of Individual Conventional Technologies Based on Site Characteristics Such as K – Should Not Take the Place of Site-Specific Pilot Testing, Analysis, Engineering and/or Design. TI Requires Technically Rigorous Analysis of Time-Series Data from Operation of Alternative Technology Recovery System OR of Data from an Appropriate On-Site Pilot Test and Modeling Study. Tn May be Incorporated into Site-Specific Pilot Testing, Analysis, Engineering and/or Design as a Direct Recoverability Threshold Metric and/or as a Calibration Parameter for a TI Modeling Study. Tn and TRRP – STEP 4 49. Conventional vs. Alt. Technologies ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 4 50. Conventional vs. Alt. Technologies ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 4 Decision Pt. for Change from Hydraulic Recovery Technology Based on Tn 51. Design Uses for Tn Estimate upper boundary for specific discharge and seepage velocity – ignores entry pressure head. Valid for plume interior, not margins. Calculate Average NAPL Conductivity from Tn and bn Specific Discharge (Darcy Velocity or Flux) Equation Yields Volumetric Flow Divide Specific Discharge by NAPL Filled Porosity to Get Seepage Velocity for NAPL - Yields Movement (distance per unit time) Tn and TRRP – STEP 4 ©2010 by H2A Environmental, Ltd., All Rights Reserved 52. Remediation Design and Tn Direct Measure of Hydraulic Recoverability Hydraulic vs. Pneumatic vs. Alternative Technology Selection Modeled LNAPL Recovery Technologies Calibrated to Readily Obtained Site Wide Tn Values Technology-Specific Production Curves Sustainability Predicted Decline Curve Analysis for Rate and Total Volume Data Relative Technology Performance Data – Technology Selection Design Cost-Benefit Analysis Projected Operational Lifetime Capital vs. Mobile Infrastructure Design Considerations Equipment Sizing Waste Mgmt / Recycling Volumes ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 4 53. Implement & Evaluate Implement NAPL Management Strategy Use Appropriate Monitoring Methods Collect NAPL Response Action Performance Data Conduct Evaluations after each Monitoring Event Evaluations (all supported by Tn) Ability of Response Action to Achieve Endpoints NAPL Endpoints Achieved? Should the Technology Change? Is TI Supported by the Data? ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP – STEP 5 54. Operational Performance Metric Single Well Recovery Data Analysis During System Operation to Monitor Tn Progress Combine with EUR and Rate-Transient Decline Curve Analysis to Evaluate Progress Towards Hydraulic Recovery Endpoint Tn and TRRP – STEP 5 ©2010 by H2A Environmental, Ltd., All Rights Reserved 55. Summary Tn is an improved metric for hydraulic recoverability Five calculation methods: Baildown Testing Manual Skimming Testing Recovery Data Analysis Physical Properties Analysis Tracer Testing Tn use as a metric Indirect – model calibration parameter Direct – recoverability (0.3-0.8 ft^2/day) TRRP-32 and Tn Design Parameter Technology Selection Production Rate Production Lifetime Model Calibration Response Endpoints Migrating NAPL Zone Contact with GW Decision Point Conventional vs. Alt. Technologies Augment Tool B for Technical Impracticability ©2010 by H2A Environmental, Ltd., All Rights Reserved Tn and TRRP 56. Section 4 Section Break Tn Examples Not in Handout ©2010 by H2A Environmental, Ltd., All Rights Reserved Editor's Notes Broad Brush – information dense slides, but we’ll cover much material quickly – handouts provide detail for reference A number of people were very generous in helping me to prepare for this presentation in various ways, including (Read list). Dr. Charbeneau, Huntley and Sale did not work with me directly, but their previous work provided much of the background for my work. Start by providing CONTEXTFour types of questions Tn can help you answer:Understanding Your Site DataComparing your LNAPL Occurrences from well to well and site to sitePredicting the hydraulic recovery rates and durations of LNAPL wellsManaging LNAPL programs across large numbers of sites to prioritize and manage potential LNAPL migration risk and recovery potential One last thing before we start: This work is based primarily on three forerunner analogs:HydrogeologyAquifer Testing and Slug Testing to get K/T to understand water movement and production (hydraulics)NORMALIZES all sites to one (1) measurement standard so you can NUMERICALLY:AnalyzeComparePredictThen use Aquifer K and T values to PREDICT and DESIGN:Pumping Rates andROCMultiphase Fluid Mechanics – Hydrogeology with another layer of COMPLEXITYLNAPL and water SHARING SPACE in an aquifer – NO PANCAKE – Density / Viscosity / Wettability and other PHYSICAL PROPERTY differences so DO NOT FLOW the sameSaturation Distribution – LNAPL Saturation highest in/near capillary fringe, always <100%Relative Permeabilities – highest LNAPL mobility in/near the capillary fringeModeling Tools to Easily Deal with Complexities – LDRM by Dr. Charbeneau / APIPetroleum Engineering TOOLS for multiphase fluid production – Decline Curve AnalysisRTA and EUR Outline Go Through SlideWhy do we talk about LNAPL T instead of K – frequently deal with K in waterLNAPL is a saturation distribution with K that varies substantially from bottom to top of mobile LNAPL profileAverage K can be used, but it is an average of a large range of values so doesn’t accurately represent either extremeHighest K and mobility at/near the capillary fringe, average K will underpredict hereTn incorporates range of K values across an entire LNAPL thickness, and so better represents the total picture of LNAPL SATURATION and MOBILITY Word of Caution: devil is in the details – must understand LCSM and all variables and adjust through time for changing variables or you will have garbage Think of these as two opposite overlapping funnels that net out as additive (drawdown plus vacuum) Critical point – inexpensive Tn values across your site give a high degree of modeling confidence without the high cost of site wide frozen core analyses