Offshore Newfoundland and Labrador Regional Rock Physics Study

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1 Offshore Newfoundland and Labrador Regional Rock Physics Study TREND SUMMARY Page 1 of 36

2 Disclaimer Ikon Science company make no warranty of any kind or character as to the reliability or suitability of this report or the data within for any purpose. The views expressed in this report are based on the best estimates of Ikon Science at the time of publication. Use of these opinions, material and data for any purpose is solely at the risk of the user and should not be used for any purpose other than for which it was intended Copyright Copyright (2015), Ikon Science, Nalcor Energy and their affiliated and subsidiary companies, all rights reserved. All trademarks belong to the respective companies and their affiliated and subsidiary companies, all rights reserved. Authorship This report (and the technical analysis within) was undertaken and written by Alsing Selnes, Nick Huntbatch, Neil Whitfield and Mathew Ogieva from Ikon Science and underwent technical management, review and guidance by Jeremy Gallop, Mike Bacon and Friso Brouwer, also from Ikon Science. The report benefitted from detailed technical and editorial review by Richard Wright, and Ian Atkinson at Nalcor Energy. Page 2 of 36

3 Contents 1.1 Introduction Stratigraphic Intervals Cut-offs and End-members Limitations AVO Modelling Look-Up Tables and VES Modelling Shale Trends Vp-TVDml RhoB-TVDml Vs-TVDml Vs-Vp RhoB-VES Vp-VES Summary Sand Trends RhoB-TVDml PhiT-Vp Vs-Vp Vp(PhiT)-TVDml RhoB-VES Summary Look-up Tables Page 3 of 36

4 1.1 Introduction Multi-well analysis was performed to derive regional trends and models for two end-member lithologies sands and shales. Each lithology was split into facies, which were determined from a combination of petrophysical analysis and elastic log behaviour in the study wells. Sand lithology consists of a friable sand case and cemented cases, with quartz cement volume varying from 2 to 8%. Shale lithology consists of a Normal (or regional) shale, which is valid for all depth intervals; a calcareous shale, for which separate trends have been derived for Tertiary-Cretaceous and ; and a cemented shale, which is observed in the deep shale data. Only 100% brine-bearing log data are used in multi-well analysis, removing the effect of any hydrocarbon-bearing data on the regional trends Stratigraphic Intervals The stratigraphy is separated into 3 intervals Tertiary, Cretaceous and. Depth trends were calibrated across all intervals, to ensure they were as robust as possible for AVO modelling. However, some trends were derived separately for specific intervals, due to the behaviour of the elastic log data Cut-offs and End-members The petrophysical cut-offs used to identify the end-member lithologies are listed in Table 1. End-member Sand Cut-offs Shale Volume (Vsh) < 0.2; Saturation (SwT) = 1; Sand Flag = 1. Normal Shale Vsh > 0.9 Cemented Shale Calcareous Shale Vsh > 0.9; trend fitted to the dense and fast data. Calc. Shale Flag = 1; Porosity (PhiT) < Table 1: End-member cut-offs. The Calc. Shale Flag was calculated using cut-offs of Vsh >0.4 and Vol_Lime >0, and the Sand Flag was calculated using cut-offs of VSh < 0.2 and Vol_Lime = 0. Both flags were manually adjusted in some parts to match the elastic log response. Limestone, though encountered in some of the wells, was not an end-member lithology for the study, so these data-points were excluded for trend analysis. Page 4 of 36

5 1.1.3 Limitations Most of the trends in this study were derived from all 6 deepwater wells Baccalieu I-78, Great Barasway F-66, Lona O-55, Mizzen F-09, Mizzen L-11 and Mizzen O-16. These trends can be considered to be reasonably robust within the range of calibration, based on the fit to the log data and sensible start and end points. However, measured Vs data were only available in three wells Lona O-55, Mizzen F-09 and Mizzen O-16. The sands encountered by these wells are all interpreted as being at least partially cemented, so measured Vs data in the sands (Figure 18) does not cover the range of cement contents encountered by the wells without measured Vs data, and the Vs-Vp trend in unconsolidated sands should be understood to be more uncertain than the other trends. This limited Vs calibration is part of the reason for the AVO modelling breaking down at very low porosity and high cementation. Further to this, the Vs in the shales (Figure 8) for Mizzen F-09 and Mizzen O-16 is of poor quality and required heavy editing during the project, which also increases the uncertainty in the Vp-Vs trends AVO Modelling The following workflow can be used to derive elastic properties as a function of depth, reservoir fluid fill, sand cement content and overpressure, which could form the input for an AVO model of a prospect: 1. Derive shale elastic properties at the prospect depth using the shale Vp, Vs and RhoB depth trends. 2. Calculate acoustic fluid properties at prospect depth. 3. Derive sand RhoB at the prospect depth using the sand RhoB-depth trend and convert to porosity. 4. Use the calibrated constant-cement model to model Vp at the prospect depth; calculate Vs from the Vs-Vp trend. 5. Fluid-substitute the sand elastic properties to the desired hydrocarbon case. 6. Use the Vertical Effective Stress (VES) trends to quantitatively investigate the effect of changing overpressure on porosity Look-Up Tables In Chapter 1.4, look-up tables are generated for a series of prospects, with reservoir depths ranging from 1500m 4500m TVDml. The first AVO modelling workflow uses the depth trends in a manner consistent with Chapter The second AVO modelling workflow uses the VES trends, in order to understand the effect that increasing pore pressure has on shale and sand elastic properties. Page 5 of 36

6 1.1.6 VES Modelling For this part of the AVO modelling workflow, the expected case is derived from the expected pressure profile, which is a fluid retention depth of 1200m TVDml, and pressure building out at 0.7 psi/ft ( MPa/m; pink line in Figure 1). This pressure profile is broadly consistent with the pressure encountered in the deep-water wells. The data are then perturbed to a highly overpressured pore pressure profile, which is a fluid retention depth of 1200m TVDml, and pressure building out at 0.95 psi/ft ( MPa/m; green line in Figure 1). This pressure profile is consistent with the highest overpressure observed in the wells and is maintained to depth, resulting in overpressures exceeding what is observed in the wells, but still geologically reasonable. This case represents a highly overpressured scenario, where porosity has been maintained at depth. Figure 1: Pressure-depth plots for Mizzen O-16, Great Barasway F-66 and Lona O-55. The blue line is a representative hydrostatic gradient (0.45 psi/ft); the red line is a representative lithostatic gradient (0.95 psi/ft); the pink and green lines are the expected and high case pressure profiles respectively; the solid squares are fracture pressure tests (leak-off tests and limit tests); the triangles are direct pressure tests (MDTs) and the empty square in Lona O-55 is a kick. Page 6 of 36

7 1.2 Shale Trends Shale depth-dependency is captured by depth trends, with separate trends for Vp, RhoB and Vs against TVDml. Shale facies, determined from petrophysical analysis and elastic log behaviour, were divided into Normal shale, calcareous shale and cemented shale. The Normal shale trend (pink line; Figure 2, Figure 4 and Figure 6) was fitted through the bulk of the shale data, identified using a cut-off of Vsh > 0.9. It was found that Normal shales from all intervals (Tertiary, Cretaceous and ) could be characterised with one depth trend. The cemented shale trend (red line; Figure 2, Figure 4 and Figure 6) was fitted through the higher velocity/rhob data, again identified using a cut-off of Vsh>0.9. The shale data for this trend are taken from deeper and hotter zones, so it is interpreted to have undergone additional diagenesis, e.g. smectite-illite transformation and cementation. Smectite-illite transformation and cementation are temperature-dependent (and therefore depthdependent) processes, so it is reasonable to assume that deep Cretaceous shales may follow a similar trend, although the only observed cemented shales are found in the in this study. The 100 o C isotherm (~3300m TVDml in this study) is generally understood to be a temperature at which smectite-illite transformation starts to have a significant effect on a shale s elastic properties. Calcareous shale (Figure 3, Figure 5 and Figure 7) was identified using a calcareous shale flag, derived during the project and separate trends were needed for the Tertiary-Cretaceous and the. VES trends for RhoB (Figure 9) and Vp (Figure 10-Figure 13) were derived to allow the effect of overpressure of shale elastic properties to be investigated during the AVO modelling phase in a quantitative manner. Vs will be modelled from Vp. The Vs-Vp trend (Figure 8) for shale has more uncertainty than other trends because there was only one well in the study with reliable Vs in the shales Lona O-55. Page 7 of 36

8 1.2.1 Vp-TVDml Cemented Cret. Normal shale Tertiary Cemented Normal shale Figure 2: Vp-Depth (TVDml) for shale data, showing Normal and Cemented shale. Upper plot: coloured by interval; Lower plot: coloured by well. calcareous Tertiary/Cretaceous calcareous shale Cret. Tertiary calcareous Tertiary/Cretaceous calcareous shale Figure 3: Vp-Depth (TVDml) for shale data, showing Calcareous shale. Upper plot: coloured by interval; Lower plot: coloured by well. Page 8 of 36

9 1.2.2 RhoB-TVDml Cemented Normal shale Cret. Tertiary Cemented Normal shale Figure 4: RhoB-Depth (TVDml) for shale data, showing Normal and Cemented shale. Upper plot: coloured by interval; Lower plot: coloured by well. calcareous Tertiary/Cretaceous calcareous shale Cret. Tertiary calcareous Tertiary/Cretaceous calcareous shale Figure 5: RhoB-Depth (TVDml) for shale data, showing Calcareous shale. Upper plot: coloured by interval; Lower plot: coloured by well. Page 9 of 36

1.2.3 Vs-TVDml Cemented shale Cret. Normal shale Tertiary Cemented shale Normal shale Figure 6: Vs-Depth (TVDml) for shale data, showing Normal and Cemented shale.

10 1.2.3 Vs-TVDml Cemented shale Cret. Normal shale Tertiary Cemented shale Normal shale Figure 6: Vs-Depth (TVDml) for shale data, showing Normal and Cemented shale. Upper plot: coloured by interval; Lower plot: coloured by well. Measured and modelled Vs shown. calcareous Tertiary/Cretaceous calcareous shale Cret. Tertiary calcareous Tertiary/Cretaceous calcareous shale Figure 7: Vs-Depth (TVDml) for shale data, showing Calcareous shale. Upper plot: coloured by interval; Lower plot: coloured by well. Measured and modelled Vs shown. Page 10 of 36

Red line: shale trend; green line: G/C shale sandstone trend; yellow line: G/C sandstone trend.

11 1.2.4 Vs-Vp Figure 8: Vs-Vp for shale data, showing all shale facies. Left plot: coloured by well; right plot: coloured by point density. Red line: shale trend; green line: G/C shale sandstone trend; yellow line: G/C sandstone trend RhoB-VES Figure 9: RhoB-VES for shale data, showing all shale. Left plot: coloured by well; right plot: coloured by point density. Page 11 of 36

1.2.6 Vp-VES Figure 10: Vp-VES for shale data, showing normal shale. Left plot: coloured by well; right plot: coloured by point density. Figure 11: Vp-VES for shale data, showing cemented shale.

12 1.2.6 Vp-VES Figure 10: Vp-VES for shale data, showing normal shale. Left plot: coloured by well; right plot: coloured by point density. Figure 11: Vp-VES for shale data, showing cemented shale. Left plot: coloured by well; right plot: coloured by point density. Figure 12: Vp-VES for shale data, showing Tertiary-Cretaceous calcareous shale. Left plot: coloured by well; right plot: coloured by point density. Page 12 of 36

13 Figure 13: Vp-VES for shale data, showing calcareous shale. Left plot: coloured by well; right plot: coloured by point density. Page 13 of 36

14 1.2.7 Summary Trend Type Lithology / Facies Interval Trend Calibration Range Vp-TVDml Normal shale Tertiary - Vp (m/s) = 5200 ( ) * e^(-2.4e-4 * TVDml(m)) m TVDml Cemented shale Vp (m/s) = 5500 ( ) * e^(-3.8e-4 * TVDml(m)) m TVDml Calcareous shale Tertiary Cretaceous Vp (m/s) = 5500 ( ) * e^(-3.1e-4 * TVDml(m)) m TVDml Calcareous shale Vp (m/s) = 5500 ( ) * e^(-5.1e-4 * TVDml(m)) m TVDml RhoB-TVDml Normal shale Tertiary - RhoB(g/cc) = 2.71 ( ) * e^(-7.75e-4 * TVDml(m)) m TVDml Cemented shale RhoB (g/cc) = 2.75 ( ) * e^(-11.4e-4 * TVDml(m)) m TVDml Calcareous shale Tertiary Cretaceous RhoB(g/cc) = 2.71 ( ) * e^(-8.8e-4 * TVDml(m)) m TVDml Calcareous shale RhoB(g/cc) = 2.76 ( ) * e^(-10e-4 * TVDml(m)) m TVDml Vs-TVDml Normal shale Tertiary - Vs (m/s) = 2783 ( ) * e^(-2.4e-4 * TVDml(m)) m TVDml Cemented shale Vs (m/s) = 2979 ( ) * e^(-3.8e-4 * TVDml(m)) Not measured. Calcareous shale Tertiary Cretaceous Vs (m/s) = 2878 ( ) * e^(-3.3e-4 * TVDml(m)) m TVDml Calcareous shale Vs (m/s) = 2978 ( ) * e^(-5.5e-4 * TVDml(m)) m TVDml Vs-Vp All shale Tertiary - Vs (km/s) = * Vp(km/s) Vp: km/s RhoB-VES All shale Tertiary - RhoB (g/cc) = * (VES (MPa) ^ E ) VES: MPa Vp-VES Normal shale Tertiary - Vp (km/s) = (-1.493E-3 * VES (MPa) ^ 2) + (0.145 * VES(MPa)) VES: 5 40 MPa Cemented shale Vp (km/s) = (-9.734E-4 * VES (MPa) ^ 2) + (0.117 * VES(MPa)) VES: 5 40 Mpa Calcareous shale Tertiary Cretaceous Vp (km/s) = (-9.734E-4 * VES (MPa) ^ 2) + (0.117 * VES(MPa)) VES: 8 15 MPa Calcareous shale Vp (km/s) = (-5.790E-4 * VES (MPa) ^ 2) + (9.266E-2 * VES(MPa)) VES: MPa Table 2: Summary of shale trends. Page 14 of 36

15 1.3 Sand Trends A single RhoB-depth trend was derived for all sands (Figure 14) in the study and the RMS error of gcm -3 was taken through to the AVO modelling phase to perturb expected density to high and low case densities. This was converted to a porosity-depth trend (Figure 15) using a matrix density of 2.65gcm -3 and a fluid density of 1gcm -3. The matrix density is guided by matching the core porosities in Lona O-55, Mizzen F-09 and Mizzen L-11. A constant-cement rock physics model (Figure 17) was fitted to the well data in PhiT-Vp space, which showed that the cement content is variable across the study wells. It was not possible to do the same in Por(PhiT)-Vs space because of the lack of measured Vs data, so a calibrated Greenberg-Castagna trend was used to derive Vs (Figure 18). The PhiT-depth trend was used as an input for the constant-cement model to derive Vpdepth trends (Figure 19) for 0% - 8% cement. The PhiT-depth trends were compared to analogue wells from the Norwegian continental shelf (Figure 16) and is shown to be a fair match to the analogue data. It is also interesting to note that the analogue data contains a number of high porosity sands at depth, with porosities beyond the high case PhiT-depth trend. A RhoB-VES (Vertical Effective Stress) trend was derived for all sands (Figure 20), which will allow the effect of overpressure on sandstone porosity, and therefore elastic properties to be investigated during the AVO modelling phase in a quantitative manner. The Vp(Por-TVDml) and RhoB-TVDml trends for sands are of the following form (shown for RhoB-TVDml): 1 = 1 RhoB RhoB matrix ( 1 RhoB matrix 1 RhoB top ) exp ( b Tvdml) Where RhoB top = density at mudline; b = compaction coefficient; RhoB matrix = density asymptote at depth. Page 15 of 36

Upper plot: coloured by interval; Lower plot: coloured by well. Low RhoB, high PhiT case High RhoB, low PhiT case Expected Cret.

16 1.3.1 RhoB-TVDml (inc. PhiT-TVDml) High RhoB, low PhiT case Low RhoB, high PhiT case Expected Cret. Tertiary High RhoB, low PhiT case Expected Low RhoB, high PhiT case Figure 14: RhoB-TVDml for sand data, showing all reservoir-quality sand. Upper plot: coloured by interval; Lower plot: coloured by well. Low RhoB, high PhiT case High RhoB, low PhiT case Expected Cret. Tertiary Low RhoB, high PhiT case High RhoB, low PhiT case Expected Figure 15: Por(PhiT)-TVDml for sand data, showing all reservoir-quality sand. Calculated from RhoB-TVDml. Upper plot: coloured by interval; Lower plot: coloured by well. Page 16 of 36

Also shown are the high, expected and low cases porosity depth trends. 1.3.

17 Figure 16:Por(PhiT)-depth data from sands in the study wells (coloured by well) and from analogue wells in the Norwegian continental shelf (coloured red). Also shown are the high, expected and low cases porosity depth trends PhiT-Vp Figure 17: Por-Vp for sand data, showing all reservoir-quality sand. Left plot: coloured by well; right plot: coloured by working interval. Page 17 of 36

18 1.3.3 Vs-Vp Figure 18: Vs-Vp for sand data, showing all reservoir-quality sand. Left plot: coloured by well; right plot: coloured by point density. Page 18 of 36

19 1.3.4 Vp(PhiT)-TVDml Figure 19: Vp-TVDml for sand data, showing all reservoir-quality sand. Calculated from PhiT-TVDml and constant-cement model. Coloured by well RhoB-VES Figure 20: RhoB-VES for sand data, showing reservoir-quality sand. Left plot: coloured by well; right plot: coloured by point density. Page 19 of 36

20 1.3.6 Summary Trend Type Lithology / Facies Interval Trend Calibration Range (m TVDml) RhoB-TVDml All sand Tertiary - RhoB(g/cc) = 1/ ((1/2.66) ((1/2.66) (1/1.765)) * e^(-4.52e-4 * TVDml(m))) m TVDml Vp(PhiT- TVDml) Friable sand Tertiary - Vp(km/s) = 1/ ((1/9.650) ((1/9.650) (1/2.035)) * e^(-1.944e-4 * TVDml(m))) Cemented sand (2%) Tertiary - Vp(km/s) = 1/ ((1/7.432) ((1/7.432) (1/2.329)) * e^(-2.429e-4 * TVDml(m))) Cemented sand (4%) Tertiary - Vp(km/s) = 1/ ((1/6.930) ((1/6.930) (1/2.423)) * e^(-2.747e-4 * TVDml(m))) Cemented sand (6%) Tertiary - Vp(km/s) = 1/ ((1/6.791) ((1/6.791) (1/2.495)) * e^(-2.847e-4 * TVDml(m))) Cemented sand (8%) Tertiary - Vp(km/s) = 1/ ((1/6.656) ((1/6.656) (1/2.518)) * e^(-2.990e-4 * TVDml(m))) Vs-Vp All sand Tertiary - Vs(km/s) = * Vp (km/s) Vp: 3 4 km/s RhoB-VES All sand Tertiary - RhoB(g/cc) = (-2.163E-4 * VES(MPa) ^ 2) + (3.320E-2 * VES(MPa)) VES: MPa Table 3: Summary of sand trends. The Vp(Por-Depth) trends are trends fitted to outputs from the constant-cement model, using the Por-Depth trend as an input. Page 20 of 36

21 1.4 Look-up Tables Look-up tables were created for prospect depths ranging from 1500m 4500m TVDml, providing elastic properties for different cases of lithofacies, and for the sands different cases of porosity and cementation. Two look-up tables were generated for each depth: a table from depth trends and a table from the VES trends. Acoustic fluid properties were modelled using FLAG algorithms, assuming a water depth of 1000m to calculate pore pressure. The change of pore fluid properties due to change in water depth has only a second order effect on the elastic properties and AVO character of the rock, so the look-up tables should be considered valid for AVO screening purposes for all water depths in the region. Page 21 of 36

22 Prospect Data Target Depth: 1500m TVDml Expected Cement: 2% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 150, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 22 of 36

23 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 23 of 36

24 Prospect Data Target Depth: 2000m TVDml Expected Cement: 4% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 200, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 24 of 36

25 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 25 of 36

26 Prospect Data Target Depth: 2500m TVDml Expected Cement: 4% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 250, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 26 of 36

27 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 27 of 36

28 Prospect Data Target Depth: 3000m TVDml Expected Cement: 6% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 300, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 28 of 36

29 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 29 of 36

30 Prospect Data Target Depth: 3500m TVDml Expected Cement: 8% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 300, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 30 of 36

31 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 31 of 36

32 Prospect Data Target Depth: 4000m TVDml Expected Cement: 8% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 300, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 32 of 36

33 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented* Uncemented Cemented Uncemented Cemented* Uncemented Cemented Uncemented Cemented* Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 33 of 36

34 Prospect Data Target Depth: 4500m TVDml Expected Cement: 8% Fluid Properties: - Salinity: 65kppm - 22 API, GOR: 5, Gravity: API, GOR: 300, Gravity: Gravity: Trends Used: Sands - Rho and Por from depth trend; Vp from Por using calibrated Constant Cement model; Vs from empirical Vs-Vp trend. Shales - Vp, Vs and Rho from depth trends. Elastic Properties: Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* Uncemented Cemented* High Porosity, Uncemented High Porosity, Cemented Low Porosity, Cemented* "Normal" Shale Tertiary/Cret. Calc. Shale Calcareous Shale Cemented Shale Page 34 of 36

35 VES Modelling Mid-case Pressure Profile: FRD: 1200m TVDml Pressure Gradient: 0.7 psi/ft VES at Lead: MPa High Case Pressure Profile (Used as OP case): FRD: 1200m TVDml Pressure Gradient: 0.95 psi/ft VES at Lead: MPa Fluid Case Vp / Vs / Rho / Por / kms -1 kms -1 gcm -3 Fract AI / gcm -3 kms -1 Vp/Vs Uncemented Cemented Uncemented Cemented Uncemented Cemented* Uncemented Cemented Uncemented Cemented* Uncemented Cemented Uncemented Cemented* Uncemented Cemented "Normal" Shale OP "Normal" Shale Page 35 of 36

36 *A feature of the model is encountered at depths greater than 3500m TVDml, for the lower porosity and higher cementation sand cases. Here, replacing brine with hydrocarbons leads to an increasing Vp. While counter-intuitive, this may well be an actual physical effect, explained though the effect of density change on Vp becoming larger than the effect of modulus change on Vp for the low porosity and very stiff rocks. Another consideration is that at the low porosities and high cementations some of the assumptions behind smann fluid substitution (sphere pack, communicating pores) may be violated, however it is unknown to what extend this would invalidate the model and results. It is left up to the user to make the final call about the reliability of the fluid substitution model in the very deep, low porosity, high cement sand. The models provide a good response for all other cases. Page 36 of 36

FRACTURE ANALYSIS FROM STANDARD TRIPLE-COMBO LOG SUITES Michael Holmes Antony Holmes Dominic Holmes

FRACTURE ANALYSIS FROM STANDARD TRIPLE-COMBO LOG SUITES Michael Holmes Antony Holmes Dominic Holmes Copyright 2015, held by the submitting authors. ABSTRACT For a realistic approach of the potential of