Characterizing The Duvernay Petroleum System In Terms Of TOC, Oil-In-Place, Thermal Maturity And Using This Data To Identify Play Fairways And Opportunities Kirk Osadetz and Zhuoheng Chen Geological Survey of Canada, Calgary 1
Shale Hosted Petroleum Resource Assessment Project a NRCAN project under Geoscience for New Energy Supply (GNES) Program with an EcoEII activity on shale gas resource methodology development (2012-2016) 2
Why shale hosted petroleum assessment Shale hosted petroleum has a profound impact on Canadas economy hosts huge amount of oil and gas resources competes with Canadas traditional petroleum resources changed industry practice on…
Major shale plays in N. America (Boyer et al 2011) 4
Why new methodology Conventional play resource assessment methodologies, such as the PETRIMES of GSC, are designed to project the number and size of discrete hydrocarbon accumulations Size by Rank within distinct structural or…
Why new assessments Industry has its own methods and results are kept confidential for their internal use. In the public domain, resource estimates are generated for different purposes, and conducted with different methodology and…
Assessments from different sources vary Five major western Canada shale basins contain 1326 TCF risked in place (U.S. Department of Energy, World Shale Gas Resources, 2011) CSUR (2010) Canada shale gas: 1111 TCF in place and tight…
Industry estimates, shale gas USGS(2011), 84.2 TCF ERCB (2012): 2133 TCF in place Horn River NEB-BC Gov.(2011): 89 TCF recoverable AAPG committee (2011): 250 TCF, USGS (2012): 36.6 TCF (from CSUR, 2013) 8
Methodology design based on characteristics of continuous resource plays, state of exploration and development (geological and production data availability), the needs from various stakeholders in Canada. 10
Features of the methodology methodology must be flexible enough to adapt to situations ranging from little or no well data to thousands of production wells, easy updating when new data become available, provide in place as well as…
Methodology under development includes four parts a volumetric approach for the in place resource estimation, a productivity-based approach for estimating the recoverable resource (if no production data available, simulated…
Method Output resource density maps outlining spatial variation of the resource potential tables and figures summarizing total resources and uncertainty ranges depending on data availability, the uncertainty associated with the…
Examples of method under development Alberta Duvernay Shale BC Horn River Shale Quebec Utica Shale 14
Duvernay shale A well-known & well studied source rock in Devonian petroleum system, WCSB A large dataset consisting of : 17000 conventional vertical wells penetrated Core/cutting samples and analysis results well logs for…
Two volumetric approaches Organic porosity-based assessment Assumptions: when kerogen converted to HC, it generates organic porosity saturated with HC remaining oil and gas in organic pores represent the in place potential Well…
Data required Organic porosity-based assessment Rock-Eval pyrolesis data Kinetic models Formation volumetric inputs: net thickness, area extent, Well log-based assessment Well log data Interpretation (calculation) models…
Burial depth to top of Duvernay 6 x 10 Burial depth at fm. top, Duvernay 6.4 5000 4500 6.3 4000 6.2 3500 6.1 3000 6 2500 2000 5.9 1500 5.8 1000 5.7 500 5.6 -1 0 1 2 3 4 5 6 5 x 10 19
Duvernay gross thickness (m) 20
Geochemical characteristics of Duvernay shale, GSC Rock Eval dataset 21
Oil generated, Duvernay 22
Oil in place estimated from S1 Mean: 69.8 Bbbls in place 23
Gas in place from volumetric Mean: 511 TCF in place 24
Problems & possible solutions Only one or a few samples in some of wells, coverage representation is inadequate 5g of sample results represent reservoir rock property at scale of 10-50 tons, up-scaling is required Well log…
Well log-based assessment Well locations penetrated Duvernay Fm. Red line marks carbonate platform or reefs 17000 wells penetrated Duvernay Fm 26
Well log analysis for identifying shale resource anomaly Well location 27
Well logs 28
Shale and conventional reservoirs identification 29
Immature Duvernay Shale 30
Immature Duvernay Shale 31
Volumetric calculation from log derived parameters 6 x 10 Oil in place, m3 rock x 10 6 6.4 3 6.3 6.2 2.5 6.1 2 6 1.5 5.9 1 5.8 5.7 0.5 5.6 -1 0 1 2 3 4 5 6 5 x 10 Mean oil in place: 129.8 Bbbls 32
Volumetric calculation from log derived parameters 6 x 10 Gas in place, m3 x 10 9 6.4 4 6.3 3.5 6.2 3 6.1 2.5 6 2 5.9 1.5 5.8 1 5.7 0.5 5.6 -1 0 1 2 3 4 5 6 5 x 10 Mean gas in place: 504.7 TCF 33
Problems & Solutions Oil in place inconsistent with organic porosity- based estimate Waiting for more accurate estimates of reservoir properties Generation kinetic models 34
Horn River case study BC MEM & NEB, 201) (figures from Close et al. 2012) 35
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Performance based method Well EUR The recoverable resource R is calculated by A R p( g ) p( p) Q S A: non-controlled area S: well drainage; Q: well EUR p(g) and p(p) probabilities of resource and at least one well economic…
Production Decline Models Valko Model An empirical model Validated for wells with both transient and stabilized flow horizontal, multi-stage fracing wells Arps Model Designed for conv. reservoirs Requires a non-transient flow…
Production curves, Horn River 39
Production curves, Horn River 40
Estimated EURs, Horn River 41
Recoverable from well EURs Triangle distr. Mode 8000 km2 Min. 4600 km2 Max. 10000 km2 Triangle distr. Mode 8 wells/sect Min. 4 wells/sect Max. 10 wells/sect Median: 142 TCF 42
Next steps Improve the volumetric models Calibration Bayesian inference Computer modeling of production curve where no production data is available Analog database Analogous criteria Performance-based data North American…
Updated volumetric EURs from well-performance EURs (Hood et al, in press) 44
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