How to Maximize the Use of TMAX, Compositional Ratios and Stable Carbon Isotopes to Accurately Infer the Maturity of a Shale Jean-Yves Chatellier Tight Oil Canada 2013 August 21st Maturity Indicators Talk Outline • Introduction • Tmax domain recognition Method to map the overpressure domain • Transformation Ratio versus Tmax • Carbon isotopes • Pseudo-depth parameters for maturity profiles • Maturity estimate conflicts • Shale dehydration in overpressured Dry Gas Domain • Quartz cement modeling – the maturity time factor • Conclusions NYSE : TLM | TSX : TLM 2 www.talisman-energy.com Rock-Eval versus Depth DEPTH Alberta Data set -2500m unreliable Tmax -3750m Calibra.on problems -5000m 17,550 data points Tmax NYSE : TLM | TSX : TLM 3 www.talisman-energy.com Vitrinite and Rock-Eval versus Depth TVDss 0m -1000m Ro from Tmax (GSC) Ro (GSC) -2000m Ro Calculated Ro calculated from Tmax using Jarvie’s equation: Ro = (Tmax*0.018) - 7.16 NYSE : TLM | TSX : TLM 4 www.talisman-energy.com Maturity Indicators in pre-Devonian Rocks Courtesy R. Bertrand (2013) NYSE : TLM | TSX : TLM 5 www.talisman-energy.com Tmax Depth Profile 1.1%Ro Beef Calcite possible generation 1.5%Ro = overpressure plane NYSE : TLM | TSX : TLM 6 www.talisman-energy.com “Beef” Calcite (calcite expansion seams) 1999.5m “beef” calcite vein Shear plane filled with calcite “beef” calcite Utica Shale St Edouard (Quebec) Very fine sedimentary fracture fill 1999.9m NYSE : TLM | TSX : TLM 3” diameter wireline core 7 www.talisman-energy.com “Beef” Calcite (calcite expansion seams) Utica Shale St Edouard (Quebec) Oil cracking and beef calcite precipitation is post thrusting in the St Lawrence Lowlands. The horizontal calcite layers crosscut a fold. NYSE : TLM | TSX : TLM 8 www.talisman-energy.com Two Important Overpressure Planes 1.1%Ro Beef Calcite possible generation 1.5%Ro = overpressure plane NYSE : TLM | TSX : TLM 9 www.talisman-energy.com Tmax versus Hydrogen Index 10-13-43-15W5 Max Tmax HI NYSE : TLM | TSX : TLM 10 www.talisman-energy.com Tmax versus Hydrogen Index 10-13-43-15W5 Max Tmax HI NYSE : TLM | TSX : TLM 11 www.talisman-energy.com Tmax versus Hydrogen Index 16-25-047-21W5 Max Tmax HI NYSE : TLM | TSX : TLM 12 www.talisman-energy.com 3-D Projection of Overpressure Plane (in blue) TVDss SSE NNW Triangle Zone Overpressure plane associated with secondary gas cracking 100km Blow-out 3-D Projection NYSE : TLM | TSX : TLM 13 www.talisman-energy.com Rock-Eval vs Transformation Ratio (TR) Alberta well 16-‐31-‐64-‐12W6 Ro calc (Tmax) TR (Pelet, PI) Tmax well profiles can be extremely useful to to build a reliable understanding of the maturity with depth Transformation ratio is totally meaningless when comparing data from various formations or various lithologies. Note the increase in scatter in the middle part of the profile Its use is even problematic within some shale with varying TOC content (varying HI original – see Quebec example) NYSE : TLM | TSX : TLM 14 www.talisman-energy.com Rock Eval vs Transformation Ratio (TR) Quebec Talisman cored wells Tmax TR (Pelet PI) Depth Depth Fm Well Lorraine Leclercville Upper Utica St David Lower Utica Data from cores in 3 different wells No useful trends Upper Utica St Edouard Misleading trends TR decrease too rapid in Upper Utica in St David NYSE : TLM | TSX : TLM 15 www.talisman-energy.com Rock Eval vs Transformation Ratio (TR) Quebec Talisman cored wells Tmax TR (Pelet) Depth Depth Fm Well Lorraine Leclercville Upper Utica St David Lower Utica Data from cores in 3 different wells No useful trends Upper Utica St Edouard Misleading trends TR decrease too rapid in Upper Utica in St David NYSE : TLM | TSX : TLM 16 www.talisman-energy.com Total Gas Content from Canisters (Saint David 1 well) Indian Castle Highest total gas Depth Indian Castle 88.97 65.95 88.94 64.90 Lower Dolgeville 66.55 59.16 48.46 One foot long canister every 5 metres Upper Dolgeville 55.18 Flat Creek 54.13 45.15 Total Gas Scf / Ton 57.92 43.17 52.15 48.86 Nice trends in Upper Utica 42.57 33.62 25.49 Total gas Scf/Ton 25.80 NYSE : TLM | TSX : TLM 37.54 Lower Dolgeville Best mechanical properties 17 www.talisman-energy.com Transformation Ratio (PI) Influenced by TOC TR (Pelet PI) Total Gas Content (TOC linked) Depth Upper Utica Lower Utica Lower Utica Total Gas Scf / Ton The TR rapid decrease is partially linked Nice trends in Upper Utica to the decrease in gas content (and linked to TOC) NYSE : TLM | TSX : TLM 18 www.talisman-energy.com Structural Control on Maturity (TR Pelet 750) Transformation Ratios (Pelet 750) in a type II North American shale unfiltered filtered A 20 miles 20 miles TR is can be very useful to reveal structural elements. In the present example a horst (Block A) at time of maximum burial is characterized by much lower maturity levels than surrounding rocks and rocks to the West NYSE : TLM | TSX : TLM 19 www.talisman-energy.com Tmax unfiltered (Utica Shale - Ohio) Ro calculated from Tmax Map view Geographic coloring based on Rock-Eval depths trends (Tmax & TR) Well behaved depth trend NYSE : TLM | TSX : TLM 20 www.talisman-energy.com Transformation ratio (Utica Shale - Ohio) TR (Pelet 750) TR (Pelet PI) At great depth there is a nice trend of TR (Pelet 750) with depth At shallow depth the same parameter exhibits unacceptable scattering NYSE : TLM | TSX : TLM 21 www.talisman-energy.com Isotopes and Compositional Ratios • Carbon Stable Isotopes • C1, C2 and C3 • Compositional Ratios • iC4/nC4 or iC5/nC5 • C3+/C1+ or C4+/C1+ • Log (C3+/C1+) NYSE : TLM | TSX : TLM 22 www.talisman-energy.com Other Maturity Indicators: Ratios and Carbon Isotopes iC4/nC4 1.1% Ro 1.5% Ro NYSE : TLM | TSX : TLM 23 www.talisman-energy.com Maturity Assessment with Carbon Isotopes Examples from Saint Lawrence Lowlands in Quebec NYSE : TLM | TSX : TLM 24 www.talisman-energy.com Carbon Isotope Reversal Carbon isotopes from isojars Ethane Propane approximation 1.1%Ro Liquid rich gas Rsquared 94.2% Rsquared 88.7% 1.5%Ro Rsquared 77.2% Rsquared 65.3% Very well defined trends in the liquid rich domain NYSE : TLM | TSX : TLM 25 www.talisman-energy.com Carbon Isotope Reversal Carbon isotopes from isojars Ethane Methane approximation 1.1%Ro Rsquared 25.1% Rsquared 88.7% Liquid rich gas 1.5%Ro Rsquared 77.2% Rsquared 16.9% Alteration of Methane isotope at and below reversal NYSE : TLM | TSX : TLM 26 www.talisman-energy.com Carbon Isotope Reversal Carbon isotopes from isojars Ethane Methane approximation 1.1%Ro Rsquared 85.8% Rsquared 86.4% Rsquared 98.1% Rsquared 91.3% Liquid rich gas 1.5%Ro Well defined trends in the liquid rich domain Major fault below the reversal predates the maximum burial NYSE : TLM | TSX : TLM 27 www.talisman-energy.com Timing of burial versus tectonics Ethane approximation 1.1%Ro Rsquared 85.8% Rsquared 98.1% Reactivated reverse fault (post max burial) Liquid rich gas 1.5%Ro Major thrust Pre maximum burial (non-altered isotope trend) Well defined trends in the liquid rich domain Major fault below the reversal predates the maximum burial NYSE : TLM | TSX : TLM 28 www.talisman-energy.com Carbon Isotope Reversal Carbon isotopes from isojars Ethane Methane approximation 1.1%Ro Rsquared 81.5% Rsquared 85.8% Rsquared 98.1% Rsquared 25.8% Liquid rich gas 1.5%Ro No obvious alteration of Methane Isotope associated with reversal NYSE : TLM | TSX : TLM 29 www.talisman-energy.com Carbon Isotope Reversal Testing isojar data set from well 3 and 3Hz Ethane Propane Rsquared 68.7% approximation 1.2%Ro Liquid rich gas 1.5%Ro Rsquared 58.6% Rsquared 71.4% Rsquared 79.9% Rsquared 93.3% Rsquared 83.2% Complementarity of data from two neighboring wells NYSE : TLM | TSX : TLM 30 www.talisman-energy.com Effect of well Interference on isotope values Methane isotopes Saint Edouard #1 Saint Edouard Hz1 approximation 1.2%Ro Liquid rich gas 1.5%Ro Exceptional differences between two neighboring wells (30 m from each other) Fracking in St Edouard 1 Methane isotope fractionation in St Edouard Hz1 This is due to well interference not to a change in maturity (in a few meters) NYSE : TLM | TSX : TLM 31 www.talisman-energy.com Pseudo depth references for maturity study • Compositional Ratios • C3+/C1+ or C4+/C1+ • Log (C3+/C1+) • Methane Carbon Isotopes NYSE : TLM | TSX : TLM 32 www.talisman-energy.com Other Maturity Indicators (gas ratio versus isotope) C3+/C1+ Wetter Produced gas data Wet gas Isotope reversal Overpressure associated with secondary cracking Dryer (C2 & C3 changed in C1) C2 Carbone isotope NYSE : TLM | TSX : TLM 33 www.talisman-energy.com Maturity Indicators Tool Dependency Log (C3+/C1+) Wetter Production gas as reference isojars isotubes Dryer C2 Carbone isotope NYSE : TLM | TSX : TLM 34 www.talisman-energy.com Maturity Gas Ratios - Tool Comparison Ratio from Chromat C4+/C1+ Chromat vs Isotubes R squared = 98.9% Ratio from Isotubes Comparison between two averages: - C4+/C1+ from chromatography ( average from ~1300 data points) - C4+/C1+ from isotubes (average from ~6 to 7 points data points) NYSE : TLM | TSX : TLM 35 www.talisman-energy.com Compositional ratio alteration (not maturity) 897m C3+/C1+ NYSE : TLM | TSX : TLM C4+/C1+ 36 www.talisman-energy.com Compositional ratio alteration (not maturity) Fault 1 897m C3+/C1+ NYSE : TLM | TSX : TLM C4+/C1+ 37 www.talisman-energy.com Wetness Increase associated with a fault Fault 1 C3+/C1+ NYSE : TLM | TSX : TLM 38 www.talisman-energy.com Maturity Estimate Conflicts • Rock-Eval / Vitrinite vs Hydrocarbon Phase matching maturity values and yield hydrocarbon drier than expectation maturity (Bakken) Hydrocarbon wetter than expectation (early migration) • Absolute values (isotopes or ratios) at reversal are Formation specific Area specific NYSE : TLM | TSX : TLM 39 www.talisman-energy.com Maturity and Shale Dehydration • Flowback Water • Increased salinity with time • Large data collection • > 100 wells • > 800 water samples • Examples using Chloride content NYSE : TLM | TSX : TLM 40 www.talisman-energy.com Dehydration in the Dry Gas Domain No data filtering TVD Flow Back Water Chloride % (~500m3) Normal increase of choride content with depth as expected in a hybrid shale system Rock dehydra.on as a func.on of Burial depth. Hydrogen from water needed to create methane from ethane or propane The chloride content is a func.on of the available connate and movable water and relate to osmosis between the frac water and the in situ waters Chloride NYSE : TLM | TSX : TLM 41 www.talisman-energy.com Dehydration in the Dry Gas Domain No data filtering TVD Flow Back Water Chloride % (~1000m3) Chloride NYSE : TLM | TSX : TLM 42 www.talisman-energy.com Dehydration in the Dry Gas Domain No data filtering TVD Flow Back Water Chloride % (~3000m3) Chloride NYSE : TLM | TSX : TLM 43 www.talisman-energy.com Dehydration in the Dry Gas Domain TVD Flow Back Water Chloride % through .me 1000m3 3000m3 500m3 Decrease in chloride content with depth below reversal : Shale dehydration Overpressure Hydrogen extracted from the interstitial water to generate methane: Dehydration C2H6+2H => 2CH4 Chloride NYSE : TLM | TSX : TLM 44 www.talisman-energy.com Quartz Cement a time dependent burial indicator very useful for basin modelling NYSE : TLM | TSX : TLM 45 www.talisman-energy.com Maturity indicator : one side of the story Different Burial but same Tmax (Ro) Depth 0 Time More recent Each of these cases has an identical maximum burial NYSE : TLM | TSX : TLM 46 www.talisman-energy.com Quartz Cement : A Time Recorder Effect of burial history on Lorraine Shale Hybrid shale can be affected by quartz cementation Schematic diagrams with percentages based on modelling Depth 80ºC Quartz Cementation Ordovician Present 2% porosity left 5% Quartz cement 21% porosity left NYSE : TLM | TSX : TLM 14% porosity left 28% Quartz cement 3% porosity left 47 No porosity left www.talisman-energy.com Rock-Eval Useful in Liquid Rich Domain What not to do: Use averages for maturity assessments Recommended steps: 1) Look at the range of values obtained 2) Filter for S2 > 0.5 and TOC > 1% 3) Document and keep in mind the percentage of bad values 4) Use the Max, or 90%ile value of Tmax as most representative 5) Incorporate all Tmax values of shallower horizon 6) On a map, incorporate all data and basement features NYSE : TLM | TSX : TLM 48 www.talisman-energy.com Conclusions • Tmax can be used using ranges and maxima • Transformation Ratio for high maturity and single shale • Carbon isotopes • Production interference can alter the C1 isotope values • Gas composition ratios • Pseudo-depth parameters for maturity profiles can be used • C3+/C1+, C4+/C1+ • Methane Carbon isotope • Liquid yield may not always match the maturity level • Shale dehydration in overpressured Dry Gas Domain • Quartz cement modeling – do not forget the maturity time factor NYSE : TLM | TSX : TLM 49 www.talisman-energy.com Thanks to Talisman Energy inc. for permission to present this material NYSE : TLM | TSX : TLM 50 www.talisman-energy.com
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