The Eagle Ford shale â what determines well productivity and ...
The Eagle Ford shale – what determines well productivity and how should it be used in forecasting? Laura Atkins Executive Director, Upstream
SEPTEMBER 17, 2014
UPSTREAM | MIDSTREAM | DOWNSTREAM | FUEL & TRANSPORT
Geology and Type Curves
Map of the Eagle Ford Hydrocarbon Windows
This map indicates hydrocarbon windows derived from geology and early time GOR data. Geology changes west of the Chittim Anticline, east of the San Marcos Arch and south of the Stuart City shelf margin. © Stratas Advisors. All rights reserved.
3
Type curves and History Match North Oil Region • North Oil region defined by the northern boundary of the play and the 8000’ structural contour. • Production is characterized by relatively low API gravities and low GORs, consistent with lower thermal maturity. • Three type curves each representing a group of wells within a range of first 3 months initial production rates and EURs used to match historical production.
• Historical well counts and IP3 Ranges:
Year 2008 2009 2010 2011 2012 2013 Total %
6 23 73 60 162 68%
66-131
1 14 11 8 34 14%
0-65 2 1 3 17 14 9 44 18%
Ave EUR Mboe Ave GOR 176 698
Source: Stratas Advisors © Stratas Advisors. All rights reserved.
132-683
4
Total 2 1 10 54 98 77 240 100%
Type curves and History Match Center Oil Region • Region defined by GORs between the 8000’ structural contour and 1500 average GOR • Production characterized by light oil with moderate GORs. • Five type curves each representing a group of wells within a range of initial production rates and EURs used to match production history. • Historical Wells and IP3 Ranges:
Year 2009 2010 2011 2012 2013 Total %
366-487 2 27 222 404 529 1184 33%
244-365 17 105 196 235 553 16%
122-243 488-2080 20 94 156 176 446 13%
26 231 396 419 1072 30%
Ave EUR Mboe Ave GOR 470 1,115 Source: Stratas Advisors © Stratas Advisors. All rights reserved.
5
0-121 1 13 70 135 92 311 9%
Type curves and History Match Center Oil/Condensate Region • Center Condensate region defined by GORs between 1,500 and 10,000. • Production characterized by very light oil or condensate with relatively low average GOR and highly prolific wells. • Five type curves each representing a group of wells within a range of first 3 months initial production rates and EURs used to match production history. • Historical Wells and IP3 Ranges: Year 2009 2010 2011 2012 2013 Total %
520-649 6 9 52 117 150 334 12%
390-519 5 9 51 113 116 294 11%
260-389 650-2210 3 8 9 48 67 221 119 382 151 392 349 1051 13% 39%
Ave EUR Mboe Ave GOR 844 4,847
© Stratas Advisors. All rights reserved.
6
0-259 6 50 152 276 189 673 25%
Total 28 125 543 1007 998 2701 100%
Other Regions • Same methodology used in all regions.
Region Ave EUR mboe Ave GOR West Oil/Condensate 523 10,986 West Gas 356 1,203,255 Center Gas 258 163,931 East 61 341 North Oil 176 698 Center Oil 470 1,115 Center Oil/Condensate 844 4,847
• West oil/condensate and West Gas regions have higher average GORs than Center oil/condensate and Center Gas Regions. • East region reflects poor historical well performance to date
History match over entire Eagle Ford play
• The influence of geology, especially thermal maturity as represented by the average GOR, on well performance is strong
• 26 type curves used to develop a play-wide history match and top line forecast • The NASQ forecast uses type curves for the top ten operators in each region and aggregates them for aplay wide forecast.
© Stratas Advisors. All rights reserved.
7
Forecasts
Eagle Ford forecast by region Most production from core areas: Center Oil, Center Oil/Cond. and West Oil/Cond.
© Stratas Advisors. All rights reserved.
9
Forecast by Hydrocarbon Detailed forecasts by region allow accurate forecasts of hydrocarbon splits
© Stratas Advisors. All rights reserved.
10
Completions
Wells Used in Completions Analysis from North Oil area to Center Oil/Condensate
© Stratas Advisors. All rights reserved.
12
North Oil Region – Wilson County
• Lower thermal maturity: Lower GOR and API gravity
• Thirteen wells analyzed • API gravity ranges from 30.0 to 37.5 • Test GOR ranges from 200 to 724
Ave EUR
Ave API
o
182
34
o
215 197 215
41 35 41
Wells 40 Hunt Oil EOG
© Stratas Advisors. All rights reserved.
13
Center Oil Region – Karnes County
• More thermally mature than North Oil Window
• Ten wells analyzed • Oil API gravity ranges from 40.0 to 47.6 • Test GOR ranges from 453 to 1383 • Lighter oil and higher GOR results in higher average EURs
Ave EUR mboe 519
© Stratas Advisors. All rights reserved.
14
Ave GOR 764
Ave API gravity 42.2
Center Condensate Region – southern Karnes County
• Wells are located in southern Karnes Co. and are all classified as gas wells • Fourteen wells analyzed with varying fracturing techniques, some using 100 mesh proppant • Well test GOR range from 3,515 to 760,565 • API gravity ranges from 51.9 to 63.9
Ave EUR mboe 741
© Stratas Advisors. All rights reserved.
15
Ave GOR 70,311
Ave API gravity 56.9
Comparison - Wilson and Karnes Co. Oil Windows
Proppant Used Million # 7 to 9 3 to 7
Average EUR mboe Wilson Co. Karnes Co. 781 1,762 354 1,025
• Wilson Co. oil window less mature with lower API gravity oil
• Karnes Co. is more mature with lighter oil (>40o API) • Larger fracs increase EUR in both areas • However, similar size fracs in Wilson Co. results in lower average EUR than those in Karnes Co.
© Stratas Advisors. All rights reserved.
16
Conclusions What is the key driver of well productivity - nature or nurture? • •
Geology (nature) is the most important determinant of well productivity However, wells can certainly be improved by better completions (nurture) – – –
•
• •
Larger overall fracs ( more stages, more proppant per stage, longer laterals) Type of proppant Other completions techniques (stages, frac fluids …)
We see larger percentage increases in well EURs from larger proppant volumes in the less productive North oil window than in the Center oil window but a larger overall increase in the Center Even with the best completion techniques, and even in core areas, we still see wells with poor IPs and low EURs (fate?) Production forecasts in a complex play like the Eagle Ford should take into consideration the innate variability in well productivity caused by changes in the geology. – –
Ongoing improvements in completions techniques can be taken into account by increasing the fraction of wells assigned to the higher rate type curves. Nevertheless, there will likely always be a fraction of wells that follow the lower rate type curves
© Stratas Advisors. All rights reserved.
17
We can help you develop a deeper understanding of the developments that are shaping the future of oil & gas. Our support includes customized consulting that is focused on a client’s specific strategic objectives, competitive challenges and asset base. Additionally, we offer support through subscription services and comprehensive market studies.
UPSTREAM | MIDSTREAM | DOWNSTREAM | FUEL & TRANSPORT 1616 South Voss Road Suite 675 | Houston, TX 77057 United States | TEL +1.713.260.6426 | stratasadvisors.com
Bogotá | Brussels | Denver | Houston | London | Melbourne | Mexico City New Delhi | New York | San Diego | São Paulo | Singapore | W ashington, D.C.
SEPTEMBER 17, 2014
UPSTREAM | MIDSTREAM | DOWNSTREAM | FUEL & TRANSPORT
Geology and Type Curves
Map of the Eagle Ford Hydrocarbon Windows
This map indicates hydrocarbon windows derived from geology and early time GOR data. Geology changes west of the Chittim Anticline, east of the San Marcos Arch and south of the Stuart City shelf margin. © Stratas Advisors. All rights reserved.
3
Type curves and History Match North Oil Region • North Oil region defined by the northern boundary of the play and the 8000’ structural contour. • Production is characterized by relatively low API gravities and low GORs, consistent with lower thermal maturity. • Three type curves each representing a group of wells within a range of first 3 months initial production rates and EURs used to match historical production.
• Historical well counts and IP3 Ranges:
Year 2008 2009 2010 2011 2012 2013 Total %
6 23 73 60 162 68%
66-131
1 14 11 8 34 14%
0-65 2 1 3 17 14 9 44 18%
Ave EUR Mboe Ave GOR 176 698
Source: Stratas Advisors © Stratas Advisors. All rights reserved.
132-683
4
Total 2 1 10 54 98 77 240 100%
Type curves and History Match Center Oil Region • Region defined by GORs between the 8000’ structural contour and 1500 average GOR • Production characterized by light oil with moderate GORs. • Five type curves each representing a group of wells within a range of initial production rates and EURs used to match production history. • Historical Wells and IP3 Ranges:
Year 2009 2010 2011 2012 2013 Total %
366-487 2 27 222 404 529 1184 33%
244-365 17 105 196 235 553 16%
122-243 488-2080 20 94 156 176 446 13%
26 231 396 419 1072 30%
Ave EUR Mboe Ave GOR 470 1,115 Source: Stratas Advisors © Stratas Advisors. All rights reserved.
5
0-121 1 13 70 135 92 311 9%
Type curves and History Match Center Oil/Condensate Region • Center Condensate region defined by GORs between 1,500 and 10,000. • Production characterized by very light oil or condensate with relatively low average GOR and highly prolific wells. • Five type curves each representing a group of wells within a range of first 3 months initial production rates and EURs used to match production history. • Historical Wells and IP3 Ranges: Year 2009 2010 2011 2012 2013 Total %
520-649 6 9 52 117 150 334 12%
390-519 5 9 51 113 116 294 11%
260-389 650-2210 3 8 9 48 67 221 119 382 151 392 349 1051 13% 39%
Ave EUR Mboe Ave GOR 844 4,847
© Stratas Advisors. All rights reserved.
6
0-259 6 50 152 276 189 673 25%
Total 28 125 543 1007 998 2701 100%
Other Regions • Same methodology used in all regions.
Region Ave EUR mboe Ave GOR West Oil/Condensate 523 10,986 West Gas 356 1,203,255 Center Gas 258 163,931 East 61 341 North Oil 176 698 Center Oil 470 1,115 Center Oil/Condensate 844 4,847
• West oil/condensate and West Gas regions have higher average GORs than Center oil/condensate and Center Gas Regions. • East region reflects poor historical well performance to date
History match over entire Eagle Ford play
• The influence of geology, especially thermal maturity as represented by the average GOR, on well performance is strong
• 26 type curves used to develop a play-wide history match and top line forecast • The NASQ forecast uses type curves for the top ten operators in each region and aggregates them for aplay wide forecast.
© Stratas Advisors. All rights reserved.
7
Forecasts
Eagle Ford forecast by region Most production from core areas: Center Oil, Center Oil/Cond. and West Oil/Cond.
© Stratas Advisors. All rights reserved.
9
Forecast by Hydrocarbon Detailed forecasts by region allow accurate forecasts of hydrocarbon splits
© Stratas Advisors. All rights reserved.
10
Completions
Wells Used in Completions Analysis from North Oil area to Center Oil/Condensate
© Stratas Advisors. All rights reserved.
12
North Oil Region – Wilson County
• Lower thermal maturity: Lower GOR and API gravity
• Thirteen wells analyzed • API gravity ranges from 30.0 to 37.5 • Test GOR ranges from 200 to 724
Ave EUR
Ave API
o
182
34
o
215 197 215
41 35 41
Wells 40 Hunt Oil EOG
© Stratas Advisors. All rights reserved.
13
Center Oil Region – Karnes County
• More thermally mature than North Oil Window
• Ten wells analyzed • Oil API gravity ranges from 40.0 to 47.6 • Test GOR ranges from 453 to 1383 • Lighter oil and higher GOR results in higher average EURs
Ave EUR mboe 519
© Stratas Advisors. All rights reserved.
14
Ave GOR 764
Ave API gravity 42.2
Center Condensate Region – southern Karnes County
• Wells are located in southern Karnes Co. and are all classified as gas wells • Fourteen wells analyzed with varying fracturing techniques, some using 100 mesh proppant • Well test GOR range from 3,515 to 760,565 • API gravity ranges from 51.9 to 63.9
Ave EUR mboe 741
© Stratas Advisors. All rights reserved.
15
Ave GOR 70,311
Ave API gravity 56.9
Comparison - Wilson and Karnes Co. Oil Windows
Proppant Used Million # 7 to 9 3 to 7
Average EUR mboe Wilson Co. Karnes Co. 781 1,762 354 1,025
• Wilson Co. oil window less mature with lower API gravity oil
• Karnes Co. is more mature with lighter oil (>40o API) • Larger fracs increase EUR in both areas • However, similar size fracs in Wilson Co. results in lower average EUR than those in Karnes Co.
© Stratas Advisors. All rights reserved.
16
Conclusions What is the key driver of well productivity - nature or nurture? • •
Geology (nature) is the most important determinant of well productivity However, wells can certainly be improved by better completions (nurture) – – –
•
• •
Larger overall fracs ( more stages, more proppant per stage, longer laterals) Type of proppant Other completions techniques (stages, frac fluids …)
We see larger percentage increases in well EURs from larger proppant volumes in the less productive North oil window than in the Center oil window but a larger overall increase in the Center Even with the best completion techniques, and even in core areas, we still see wells with poor IPs and low EURs (fate?) Production forecasts in a complex play like the Eagle Ford should take into consideration the innate variability in well productivity caused by changes in the geology. – –
Ongoing improvements in completions techniques can be taken into account by increasing the fraction of wells assigned to the higher rate type curves. Nevertheless, there will likely always be a fraction of wells that follow the lower rate type curves
© Stratas Advisors. All rights reserved.
17
We can help you develop a deeper understanding of the developments that are shaping the future of oil & gas. Our support includes customized consulting that is focused on a client’s specific strategic objectives, competitive challenges and asset base. Additionally, we offer support through subscription services and comprehensive market studies.
UPSTREAM | MIDSTREAM | DOWNSTREAM | FUEL & TRANSPORT 1616 South Voss Road Suite 675 | Houston, TX 77057 United States | TEL +1.713.260.6426 | stratasadvisors.com
Bogotá | Brussels | Denver | Houston | London | Melbourne | Mexico City New Delhi | New York | San Diego | São Paulo | Singapore | W ashington, D.C.
