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DL PETROLEUM ENGINEERING AND CONSULTING LIMITED Presentation Prepared By: Dale Lee, P.Eng. May 30, 2013 Google AGENDA DL Petroleum Engineering and Consulting Ltd. Waterflood Concepts Our Methodology Devon Waterfloods (Diana Goldstein) Q&A DL PETROLEUM ENGINEERING AND CONSULTING LIMITED Engineering focus Analyze reservoirs’ production performance Predict the locations of underperforming wells Injectors and Producers Predict underperforming regions of reservoirs Infill Drilling injector conversions Primary Analytical Tool: Oil Field Manager (OFM) DL PETROLEUM ENGINEERING AND CONSULTING LIMITED Engineering focus Statistical analyses of hydrocarbon production Spatial statistics (i.e. kriging & Regression Analysis) P etro-physical data Pressure & Production history Purpose Optimize hydro-carbon recovery Make money DL PETROLEUM ENGINEERING AND CONSULTING LIMITED Previous Studies: Arsenal Energy: Bangladesh (BGFCL): Devon Energy: CNRL: Petro-Canada: Provost Area – Analyzing pools Titas – non associated gas field Ferrier – waterflood Nipisi – waterflood Grand Forks – waterflood Golden Lake – heavy oil waterflood Bellshill Lake – bottom water drive Wapiti – primary oil production Williston Green - waterflood WATERFLOOD CONCEPTS Objectives of Waterflooding Maintain pressure support above bubble point Keep gas in solution Minimize oil viscosity (gas dissolved in oil) Physical displacement of the oil by the water Balance the voidage replacement ratios (VRR) VRR = (Injection/Production) at res. conditions Optimize oil recovery WATERFLOOD CONCEPTS Pressure Temperature phase envelope C to C 1 considered waterflood zone Pet r o l e um S o c i et y C a n a d i a n I n s t i t ute o f M i n i n g , M et a l l ur g y & Pet r o l e um , D ete r m in a t i o n o f O i l a n d G a s Re s e r v e s , Pet r o l e um S o c i et y M o n o g r a ph N o . a , P g . 1 47 WATERFLOOD CONCEPTS Criteria for Waterflooding Geology (k, θ, Sw, heterogeneity index) Single layer model (Buckley Leverett) Multi layer model (Dykstra and Parsons) Gas saturation ′ ∗ < (Craig, The Reservoir Engineering Aspects Of Waterflooding) Mobility ratios 0.3 < ( ∗ )/( ∗ ) < 10 ( ∗ )/( ∗ ) = 1, Ideally WATERFLOOD CONCEPTS Four stages of Waterflooding Start of injection to interference Interference to fill-up Fill up to breakthrough Breakthrough to economic flood-out limit Injection rates ( piston displacement ) = 2 ∗ until fill-up = after fill-up WATERFLOOD CONCEPTS Recovery Factor (RF) RF = Displacement Efficiency (DE) x Volumetric Sweep Efficiency (VSE) 1 − − = 1 − = ( ∗ ) WATERFLOOD CONCEPTS - Variable - Constant Google: https://www.google.ca/search?q=water flood&hl=en&rlz=1C2SFXN_enCA499CA522&tbm=isch&tbo= u&source=univ&sa=X&ei=rG2dUa3KHIr9iQLf7oH4Cg&sqi=2&ved=0CEEQsAQ&biw=1680&bih=863, May 22, 2013 – Date Accessed WATERFLOOD CONCEPTS Determine ROIP (Remaining oil in place) = ∗(1− )∅ℎ from start of waterflood Determine OOIP (Original oil in place) = ∗(1− )∅ℎ Determine recovery factor at start of waterflood % = ( −) ∗ 100 WATERFLOOD CONCEPTS Example – Ferrier Unit #2 (Devon) WATERFLOOD CONCEPTS FERRIER PERFORMANCE WATERFLOOD CONCEPTS VOIDAGE REPLACEMENT RATIO = + + = + + WATERFLOOD CONCEPTS PRESSURE DATA ANALYSIS STEPPED, INTERPOLATED AND FITTED PRESSURE VARIABLES Waterflood_Patterns (90) 48000 40000 32000 24000 16000 Waterflood_Patterns (90) BHSI Pressure ( kpa ) Stepped Res Press ( kpa ) Interpolated Reservoir Pressure ( kpa ) Fitted Reservoir Pressure ( kpa ) 0 1963 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 05 07 09 8000 Date WATERFLOOD CONCEPTS FLUID PVT DATA WATERFLOOD CONCEPTS FRACTIONAL FLOW (WATER) Fractional Flow equations = + + = ∗ ℎ − ln Used to calculate average (point) water saturation around a given producer = 1/(1 + ( ∗ )/( ∗ ) + ( ∗ )/( ∗ )) Used to generate fractional flow plot as a function of water saturation, Sw, (Buckley Leverett) WATERFLOOD CONCEPTS FERRIER EXAMPLE WATERFLOOD CONCEPTS FRACTIONAL FLOW CURVE (WATER) WATERFLOOD CONCEPTS PRODUCER WATER SATURATION OUR METHODOLOGY Our methodology delivers: Production Forecasts - Fractional Flow Analyses Production Trends - OFM Scatter Plots Production Trends - Aerial Maps Individual Well Production Analysis Regional or Pattern Production Analysis Inadequate Injection Support Identification Damaged Injector Identification OUR METHODOLOGY FRACTIONAL FLOW (OIL) Fractional Flow equations = + + = ∗ ℎ − ln Used to calculate average (point) oil saturation around a given producer = 1/(1 + ( /( ) + ( )/( )) Used to generate fractional flow plot as a function of oil saturation, So OUR METHODOLOGY FRACTIONAL FLOW (OIL) OUR METHODOLOGY FRACTIONAL FLOW (@SO) OUR METHODOLOGY FRACTIONAL FLOW (WATER) OUR METHODOLOGY FRACTIONAL FLOW (OIL) OUR METHODOLOGY FRACTIONAL FLOW (GAS) OUR METHODOLOGY FORECAST - FRACTIONAL FLOW OUR METHODOLOGY PRODUCER OIL SATURATION OUR METHODOLOGY PRODUCER QUADRANT ANALYSIS OUR METHODOLOGY CONFORMANCE PLOTS OUR METHODOLOGY CONFORMANCE PLOTS Conformance plot of recovery factor as a function of hydrocarbon pore volume injected for each pattern. The thick black line represents the average pattern OUR METHODOLOGY INJECTOR HALL PLOTS OUR METHODOLOGY INCREMENTAL OIL CALCULATIONS 12.5 Working Forecast Phase Case Name b Di qi ti te Final Rate Cum. Prod. Cum. Date Reserv es Reserv es Date EUR Forecast Ended By DB Forecast Date Reserv e Ty pe Oil Rate (CD) per Well, m3/d 10.0 7.5 Parameters : Oil : Case1 : 6.9566 : 0.0297993 A.e. : 1.5671 m3/d : 07/30/2008 : 07/31/2018 : 1.31753 m3/d : 34.273 Km3 : 12/31/2012 : 2.77498 Km3 : 07/31/2018 : 37.048 Km3 : Time : Not Sav ed : None 5.0 2.5 0.0 2000 01 02 03 04 05 06 07 08 09 Date 10 11 12 13 14 15 16 17 18 The red curve is used as a base line for calculating incremental reserves ( 100,000 bbl) OUR METHODOLOGY STATISTICAL ANALYSIS Year 2010 First regression Fit 43 of 139 wells Second regression Fit 23 of 139 wells Third regression Fit 11 of 139 wells Total fit 77 wells ± 20% = − 100 OUR METHODOLOGY STATISTICAL ANALYSIS Statistical Study 139 wells 77 modeled ± 20% 16 wells under performed 46 wells over performed (e.g. pressure support) OUR METHODOLOGY STATISTICAL LIMITATIONS Statistical Limitations: Regression equations are only valid for the dataset analyzed Attention to end points (e.g. modeling relative permeability curves) Statistical models iterative Results can change with dataset and location Fractional flow analysis can not be generalized One reservoir is not necessary representative of other reservoirs Each dataset requires individual analysis OUR METHODOLOGY FRACTIONAL FLOW (OIL) First presented at the 46 th Annual Technical Meeting May, 1995 in Banf f Published in the Journal of Canadian Petroleum Technology, August 1996 NEXT: DEVON WATERFLOODS (DIANA GOLDSTEIN)