Modeling Lateral Accretion in the McMurray Formation at Grizzly Oil Sands Algar Lake SAGD Project

Transcription

1 Modeling Lateral Accretion in the McMurray Formation at Algar Lake SAGD Project Duncan Findlay 1, Thomas Nardin 1, Andrew Couch 2, Alex Wright 1 1 ULC, 2 EON

2 Introduction Laterally accreting channel systems are important reservoirs in the McMurray Formation. These reservoirs are by their nature stratigraphically complex and heterogeneous Inclined Heterolithic Strata. SAGD performance (SOR, RF, Oil Rate) is strongly dependent on the distribution of permeability within these depositional systems. Therefore, realistically representing the stratigraphic architecture in geological models is required to accurately predict reservoir performance. Here we present a geomodel which incorporates geometries of the reservoir with outcrop observations, core, log and 3D seismic data at Algar Lake property.

3 Land Holdings 800,000+ Net Acres of Alberta Oil Sands Leases Lease Other Oil Sands Lease Alberta Oil Sands Areas Producing Thermal Project Under Construction Thermal Project Thickwood Hills 38,400 contiguous acres of oil sands leases Cadotte - ~50,000 contiguous acres of oil sands leases Windell Rail Terminal Algar Lake - 56,960 contiguous acres of oil sands leases at the center of the Athabasca region May River - 46,720 contiguous acres of oil sands leases

4 Algar Lake Location and Regional Setting McMurray-Wabiskaw Isopach T88 T87 T86 Project Area T85 Algar Lake T84 T83 T82 T81 Isopach truncated at 40 m contour R14 From Nardin et al 2013 R13 R12 R11 R10 R8W4

5 Algar Lake Data Base Grizzly May River OSL 3D Seismic Model Area Project Area Algar Lake Phase 1 McMurray Reserves 114 mmbls 2P Reserves 35 mmbls BE Contingent Resource GOS submitted a 11,300 bopd SAGD development application in 2010 Phase 1 to provide 6,000 bbls/d of long-term bitumen production 4x10 well pads in the development area Approval received in Nov 2011 First steam achieved in January 2014 from the ARMS prototype plant Total of 48 wells in the model area (~1580 hectares) 3D seismic covers most of the model area

6 ARMS SAGD Facility

7 Algar Lake McMurray Formation Reservoir McMurray C Net Pay Algar Lake Reference Well AB/ W4 Reservoir Characteristics - Excellent quality, multi-darcy McMurray fluvial sands - Avg por = 33%, So = 80% - Net pay up to 22 m directly overlying Devonian limestone - No associated bottom water or gas - Capped by 40 m thick Clearwater shale section

8 Algar Lake Stratigraphic Model Sand Sand Sand

9 Algar Analogue - DPP S Abandonment Sandy Base Inclined Fluvial Deposits

10 Modern Analogue El Sira Point Bars, Peru 10km

11 Outcrop examples of McMurray IHS Wabiskaw McMurray Fm Clast Associated Mudstones McMurray Fm Bioturbated Muddy IHS

12 3D Seismic Interpretation NW Wabiskaw SE Wabiskaw D McMurray Devonian 3D Seismic tied to available well control Major stratigraphic surfaces and differential compaction within the McMurray can be resolved : Abandonment Dipmeter data is required to determine the direction of lateral accretion NW SE

13 Dipmeter Analysis Pad B Devonian Structure with Dip Azimuth

14 IHS revealed in the Injectors

15 Dip Surface Map

16 Variograms Analysis in IHS At a 400m well spacing, you will have a maximum of 2 data points on a single lateral accretion surface. Not enough for a good variogram. Outcrop measurements indicate that individual facies bed lengths are generally less than this. Need another way why not use outcrop bed length statistics?

17 Variogram Analysis in IHS Nardin et al 2013 Select major and minor variogram directions from field observations of mud bed length Often smaller in extent than could be calculated from well data Using a local varying azimuth function, orientation can be controlled on a curved surface Results in geomodels that resemble outcrops

18 Lithofacies Core examples of the McMurray B lithofacies used in the Algar Lake geologic model.

19 McMurray Outcrop Vs Algar Model

20 Algar Lake Facies Model 20

21 PSD to Permeability As core expands with retrieval, complicating permeability and porosity measurement, it would be useful to measure permeability from a dilation independent variable Several equations available in the literature for calculating permeability from PSD data Possible applications in the McMurray Formation? d90 d50 d10

22 May River Calibration Dataset r 2 =0.83 n=67 r 2 =0.94 n=10 d10 vs. horizontal permeability for Sand Highest correlation coefficient from the d10 value Best described by a complex polynomial curve d10 vs. horizontal permeability for Sand15 d10 value provides the strongest correlation Best described by a simple 2 degree polynomial

23 May River Calibration Dataset All previous trends can be combined in a nested If function Provides good results for the calibration dataset Occasional busts Promising initial results To be applied to Algar dataset for further evaluation and refinement

24 May River Calculated Perm Model May River Porosity Perm Model May River Grain Size Perm Model

25 Conclusions It is important to realistically capture stratigraphic architecture Populate lithofacies into the stratigraphic architecture using quantitative outcrop data Reservoir parameters keyed to this realistic lithofacies model, i.e. permeability, gives a better representation of the reservoir There is a good relationship between permeability and the D10 of the particle size distribution Investigation of PSD utility is ongoing

26 References Alberta Energy and Utilities Board, 2003, Athabasca Wabiskaw-McMurray regional geological study report 2003-A: Calgary, Alberta Energy and Utilities Board, 187 p. Deschamps, R., Guy, N., Preux, C., and Lerat, O., 2012, Analysis of Heavy Oil Recovery by Thermal EOR in a Meander Belt: From Geological to Reservoir Modeling; Oil & Gas Science and Technology V 67, No. 6, p Hubbard, S. M., D. G. Smith, H. Nielsen, D. A. Leckie, M. Fustic, R. J. Spencer, and L. Bloom, 2011, Seismic geomorphology and sedimentology of a tidally influenced river deposit, Lower Cretaceous Athabasca oil sands, Alberta, Canada: AAPG Bulletin, v. 95, p Jablonski, B.V.J., Process sedimentology and three-dimensional facies architecture of a fluvial dominated, tidally influenced point bar: middle McMurray Formation, lower Steepbank River area, northeastern Alberta, Canada: Master s thesis, Department of Geological Sciences and Geological Engineering, Queen s University, Kingston, Ontario, Canada, 356 p. Nardin, T.R., Feldman, H.R., and Carter, B.J., Stratigraphic Architecture of a Large-Scale Point Bar Complex in the McMurray Formation: Syncrude s Mildred Lake Mine, Alberta, Canada. in F.J Hein et al (Eds.). Heavy-oil and Oilsand Petroleum Systems in Alberta and Beyond. AAPG Studies in Geology 64, p Su, Y., Wang, J.Y. and Gates, I.D., 2013, SAGD well orientation in point bar oil sand deposit affects performance; Engineering Geology 157, p

27 Algar Horizontal Perm Model