Do we have the right rock types in our reservoir simulation models? PETROTYPING A basemap and atlas for navigating through permeability and porosity data for comparison and permeability prediction - or what can you do with s of core plugs? Patrick Corbett Patrick Corbett and David Potter Institute of Petroleum Engineering, Heriot-Watt University, Riccarton, Edinburgh Institute of Petroleum Engineering, Heriot-Watt University, Riccarton, Edinburgh SCA Outline Rock Typing by Hydraulic Units The problem with Hydraulic Units Petrotyping (Global Hydraulic Elements) The advantages of Petrotyping Engineering Validation Cluster analysis on core plug data Hydraulic Flow Unit is defined as the elements of the reservoir rock which have similar averages of petrophysical rock properties that affect fluid flow Amaefule, 99 Derivation of Hydraulic Flow Elements k = τ rmh = S gr r ( ) k = = τ F g τ Sgr r mh Definition of and FZI From Koseny-Carman equation Koseny-Carman equation k = F g τ Sgr ( ) - Reservoir Quality Index FZI - Flow Zone Index. k = ( = z ) Fg τ S gr HU HU HU HU Hydraulic Units. FZI Log() = Log(z) + Log(FZI)... z
Visualization of HUs PermeabilityPermeability-Porosity Coded by HU Grain size fining Probability Plot for identify HFE's, G-9..9 Subdivision of the Hydraulic Flow Units HU Normal Probability... HFE. HFE. Crossplot of (k vs. Phi) for different Hydraulic Units, Well X HFE. Plot of vs. Φz, well G HFE HFE. HFE, FZI=.9 HFE, FZI=. HFE, FZI=. HFE, FZI=. HFE, FZI=.......8. Empirical Probability k, md HU HU.8............ Φz Phi, frac. Reservoir Quality Index vs. Flow Zone Indicator PoroPerm relationship is uniquely defined for each Hydraulic Unit From Mohammed, (from Ellabad, ) The problem with HUs Lack of implied geometry Non-facies specific Cant be correlated and mapped Crossplot of (k vs. Phi) for different Hydraulic Units, Well X Crossplot of (k vs. Phi) for different Hydraulic Units, well X... Crossplot of (k vs. Phi) for different Hydraulic Units, Well X k, md k, md Clusters systematically selected on statistical grounds Depend on available sample set Field-specific Clustered on well by well basis HU s across a field Permeability, md............... Porosity, frac........ Phi, frac..... Phi, frac. Different numbers of HUs Different HUs (from Ellabad, ) Petrotyping GLOBAL HYDRAULIC ELEMENTS Global Hydraulic Elements (Standard HU s) Grounded quantitatively or porosity and permeability Consistent classification of rock type on petrophysical criteria A-priori petrotypes FZI 8 9 8 (cf rock type, pore types, pore groups)....8.98 Transportable (cf grain size comparator) Standard representation plot and colours Number of petrotypes absolute not relative Use of element implies spatial knowledge (cf stratal element) FZI = Φz. = k
Coarsening-up Shoreface Median Grain Diameter (mm) CHALK. mu. ml.. fu.. fl. vfu.. Data from Peter Frykman, GEUS Shallow Marine (North Africa) Shallow Marine Trends Shallow Marine (North Africa) SHALLOW MARINE Uses of Petrotyping Comparing Fields Comparing fields Visual (standard colour scheme) A priori trends Permeability prediction Comparing Databases Common patterns Field A Eclipse model data Field B
Comparing Models Field A Eclipse model data Field B Comparing Fields SPE Comparative Solution Project Turbidite Trends Braided Fluvial Braided Fluvial Trends Braided Fluvial Trends Global Hydraulic Elements 9 8 Coarse Medium Fine Very fine Permeability (md)......... Porosity (decimal) Piraces, La Serreta, Huesca Fan, Ebro Basin
A-priori trends Petrotype Comparison of Databases Aeolian Turbidite Trends Shallow Marine Trends Aeolian facies distributions.... fluvial deltaic aeolian chott... lagoon. probability Probability, fraction. tidal flat. mixed tidal. deltaic aeolian.. washover. -. North Africa 8 9 Middle East 8 9 Database: several thousand core plugs Braided Fluvial Trends (from Kooistra, ) Petrophysical Validation of HFEs. 8 Air-Mercury Capillary Pressure (psia) Grain Size and Sorting, Phi Units Rock types and flow M ercury Injection Capillary Pressure Mercury Injection Capillary Pressure GrainSize Sizeand and Sorting each HU HFE Grain Sortingforfor each.. Sample #9 - HFU Sample # 9- k = k = HFE Sample # - HFU Sample # - k = k 8 = 8 HFE Sample # - k = k. =. HFE Sample # - HFU 8. GHU GHU GHU GHU GHU GHU HFESUnits Hydraulic 8 9 Wetting Phase Saturation (%) Escanilia Fm, Olsen Grain size shows clear contrast among HFEs, where sorting shows no big variation HFEs characterized also by different capillary pressure curves Geochoke Model Pixel Model Braided Fluvial Rock Type Distribution Braided Fluvial, Triassic, North Africa, Ellabad, Petrotyping in Carbonates s can be found Needs more systematic work! Numerical Well Test Simulations Ellabad,
Carbonbate Rock Types Petrotype Petrotype Petrotype Petrotypes (from Masalmeh and Jing, ) Conclusions Petrotyping: Use of Global Hydraulic Elements Consistent Basemap Comparable Colours A-priori Information Standardisation of databases Basis for: SCAL selection (S = Systematic) Permeability Prediction Correlation and Mapping Property Assignment and Reservoir Modelling Acknowledgements Total support for PWMC Anadarko support for DP Pegasus project sponsors Amerada Hess, BG, Halliburton and Schlumberger