The Discovery, Reservoir Attributes and Significance of the Hawkville Field and Eagle Ford Shale Trend - A Texas
Giant North American Gas Discovery*
Richard K. Stoneburner1
Search and Discovery Article #10552 (2013)
Posted December 9, 2013
*Adapted from oral presentation given at AAPG International Conference and Exhibition, Cartagena, Colombia, September 8-11, 2013. Please refer to closely related
article by the author; it is entitled “The Exploration, Appraisal and Development of Unconventional Reservoirs: A New Approach to Petroleum Geology, Search and
Discovery Article #41115 (2013).
**AAPG © 2013 Serial rights given by author. For all other rights contact author directly.
1
Advisor to Pine Brook Partners; Director for Newfield Exploration, Yuma Exploration and Cub Energy, (stoneburner@dontknow.com)
Abstract
The discovery of the Hawkville field in October, 2008, represented the first commercial production from the Eagle Ford Shale. Since that time
the trend has seen a remarkable surge in drilling activity that has resulted in a current production level of almost 1 million barrels of oil
equivalent per day. The discovery process by the Petrohawk Energy Corporation exploration team followed by the detailed petrophysical
evaluation of the reservoir character verified that the Eagle Ford shale is truly a world class shale reservoir that has changed the landscape of
hydrocarbon production from both the state and the country.
The exploration process was a classic example of the "inside out" approach utilized in exploring for unconventional reservoirs, as contrasted to
the "outside in" approach utilized in exploring for conventional reservoirs. The subsurface study identified a local area in LaSalle and
McMullen Counties that displayed excellent petrophysical parameters in the Eagle Ford. A geochemical analysis was then performed on
cuttings from a well in the area of interest that produced favorable results. Lastly, a seismic signature was identified that enabled a discreet, but
very large, buy outline to be defined. A total of approximately 160,000 acres was quickly assembled and a well was then drilled and completed.
The entire process from concept to discovery only took approximately 10 months.
Subsequent to the discovery a thorough petrophysical, geochemical and geomechanical study was undertaken to better understand all aspects of
the reservoir. The basis for this study was the data derived from the discovery well and pilot well program, with the data acquired from the
whole core grid providing the basis for the study. Once the core data was acquired, a methodical effort was made to calibrate the core data to
the open-hole log data. The resulting data set provided the basis for a wide array of interpretations that greatly aided the appraisal process.
The discovery of the Hawkville field and other discoveries made by industry partners in the Eagle Ford made it apparent that the trend was
going to provide a significant boost to the production of oil, gas and natural gas liquids in the United States. The effects of that production
increase are beginning to make a difference in the security of the country’s hydrocarbon supply. However, the potential for significant
production growth beyond what has already been achieved could greatly enhance our prosperity.
“The Discovery, Reservoir Attributes
and Significance of the Hawkville Field
and Eagle Ford Shale Trend: A Texas
Giant North American Gas Discovery”
AAPG ICE: Discovery Thinking Forum
September 10th, 2013
Richard K. Stoneburner
Formerly: President and COO Petrohawk Energy and President NA Shale
Production Division BHP Billiton Petroleum
Currently: Advisor to Pine Brook Partners; Director for Newfield Exploration,
Yuma Exploration and Cub Energy
Growth of North American Shale Production
• The development of isolated multi-stage hydraulic fracturing in
2006 caused a dramatic increase in shale production
7,0
Development of isolated multi-stage
hydraulic fracturing
Marcellus
Today
6,0
Barnett
BCFE/D
5,0
Haynesville
4,0
3,0
2,0
1,0
,0
Fayetteville
Marcellus
Woodford
Eagle Ford
Exploration Process
Unconventional Exploration: A Different Way of Thinking
Conventional
Unconventional
•
Project identification focuses
“outside in”
•
Project identification focuses “inside
out”
•
Seismic control works “outside in”
•
Seismic control works “inside out”
•
Stratigraphic support eventually
focuses on the facies analysis local
to the prospect
•
Stratigraphic support focuses on
analysis of the entire basin
•
Reservoir quality analysis is required
over a very broad area of the basin
•
Reservoir quality issues are
relegated to the area of the prospect
Prospect Identification: Conventional Analogy
K2
Shenzi Prospect
Neptune
Mad Dog
Atlantis
0
Discoveries
•
•
•
•
20000
US feet
Deep Water Gulf of Mexico Prospect
Structurally controlled and supported by local analogs
At time of Prospect Identification, three significant analogs in the area of the prospect
The area of the prospect was on the order of 10K acres with resource potential
of 100-200 MMBOE
Prospect Identification: Unconventional Analogy
GUADALUPE
GONZALES
BEXAR
LAVACA
WILSON
DEWITT
VICTORIA
FRIO
ZAVALA
ATASCOSA
GOLIAD
MAVERICK
CHOKE
CANYON
RESERVOIR
DIMMIT
BEE
COLETO
CREEK
RESERVOIR
LIVE
OAK
LAKE CORPUS
CHRISTI
WEBB
DUVAL
•
•
•
•
Eagle Ford Shale Prospect
Known regional source rock across large petroliferous basin
Reservoir quality and geochemical attributes poorly understood
The area was >10 MM acres with high side resource potential of >10 BBOE
Case Study for Unconventional Exploration:
Hawkville Field
•In early 2008 the CEO of Petrohawk charged the Exploration team to find another
“Haynesville-like” play
o Our Fayetteville and Haynesville experience provided a level of experience
in evaluating shale reservoirs that potentially allowed for a quick
evaluation
•We targeted the Eagle Ford Shale based on its significance as a regional source
rock
o Q1: Mapped the Eagle Ford across the entire Gulf Coast Basin and
identified an anomalously thick, porous and highly resistive Eagle Ford
section in La Salle and McMullen Counties
o Q2: Acquired Eagle Ford cuttings on a key well and had them analyzed for
TOC, VRo and other key parameters
o Q3: Acquired ~160,000 acres and spudded the initial test well
o Q4: Completed it in October 2008 for 7.6 Mmcf/d and 251 Bc/d
Hawkville Field in Early 2008
X/Y:
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15000
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10000
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0
0
-5000
-5000
-10000
-10000
-15000
-15000
-20000
-20000
WILSON
DE WITT
ZAVALA
FRIO
KARNES
ATASCOSA
VICTORIA
MAVERICK
GOLIAD
Phillips LaSalle #1
MCMULLEN
DIMMIT
BEE
LA SALLE
Swift Pielop #1
•
•
•
LIVE OAK
Very limited well control in prospective area
Prospect was located in a regional setting between two divergent shelf margins,
which suggested the presence of a “mini-basin”
While the geochemical properties were unknown, the depth range (10,00011,500’/3050m-3500m) suggested a relatively mature source rock
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1864700
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Key Finding #1:
World Class Petrophysical Properties
Atascosa_bee_dewitt_gonzales_liveoak_lasalle_maverick_webb_wilson
10920
10940
10960
10980
11000
11020
11040
11000
Log
Depth(ft)0
10900
0
Log
Depth(ft)
10900
10920
10940
10960
10980
11000
11020
11040
11060
11080
11080
11100
11100
11060
11100
11120
11140
11140
11160
11160
11180
11180
11200
11200
11120
11200
11220
11220
11240
11240
11260
11280
11300
Buda
11300
•Well was drilled in the early
‘90’s, probably targeting the
Cretaceous Olmos Sands
•Eagle Ford tested small amount
of gas after light acid treatment
•Over 250’ (75m) of Eagle Ford
greater than 9% density, with
majority greater than 15%
(~100% Net/Gross)
•Excellent resistivity
•Gamma Ray character indicative
of “coarse”-grained mudstone
Primarily
oil Pielop 1
Swift
Significant portions
GR
AT90
PHIDEDIT
Resistivity
Density
de-risked
120
0
100 0.3
Early entry, low avg.
Eagle Ford Shale
cost
Scalable
Longer-term leases
Low near-term capital
requirements
11260
11280
11300
Key Finding #2:
Positive Geochemical Analysis
Phillips LaSalle #1
D&A in 1952
Eagle Ford Shale Gas Risk Assessment Diagram
TOC (0-5)
AC
EFS
Tr (50 – 100)
Ro (0.2 – 2.2)
Minimum Threshold
BUDA
Phillips LaSalle #1
Tmax (435 - 470)
Dryness (0 – 100)
Key Finding #3:
Seismic Defines the Optimum Reservoir Thickness
MT 3D CookWest MIG TVF, 401, 1130
SP:
4800.0
4820.0
MT GT LR-37, 160.74
MT 3D LAKEWOOD - BURKS
MT RANCH,
GT 77-16,1482,
378.02
125
4840.0
- MT GT 65-253 616 MIG TVF 4900.0
4880.0
4920.0
MT 3D LAKEWOOD - BURKS RA
4940.0
4960.0
4980.0
Dora Martin 2H
Dora Martin 4H
Dora Martin 1H
Dora Martin PH 1
Dora Martin 2H
1H
1.500
• The anomalously thick
Eagle Ford at Hawkville
could be identified
with 2D seismic data
MT GT 927 MIG TVF, 1368.54
4860.0
1.600
Isochron Thick in Center of Hawkville Field
1.700
1.800
1.900
EFS Res
Res
EFS
2.000
• A grid of existing 2D
data was acquired that
allowed the mapping
of the Eagle Ford >150’
(45m)
EFRT
EF
SR
es
Buda
2.100
2.200
Eagle Ford Shale
2.300
2.400
2.500
Data Courtesy of Seitel, Inc.
Hawkville Field in Late 2008
Petrohawk Energy
Dora Martin #1H
Spud
Date:09/2008
1st Prod: 01/2009
Petrohawk Energy
STS #1H
Spud
Date:07/2008
1st Prod: 10/2008
Fall 2008
Petrohawk Acreage Position
~160,000 net acres
The Eagle Ford Shale in 2013
Eagle Ford Shale
Competitor Map
A New Set of Lights Visible From Space
Appraisal Process
The Appraisal Process:
Core Data and “Core to Log” Data are Critical
• There is nothing more critical to the evaluation of a shale resource than the
extensive data gathered from whole core analysis:
o Measurement of “conventional” reservoir attributes such as Porosity, Sw,
Permeability, etc.
o Identify and measure the mineralogy, specifically clay minerals versus “coarse”grained constituents
o Measurement of key geochemical (TOC, Thermal Maturity, etc.) and
geomechanical attributes (Young’s Modulus and Poisson’s Ratio)
o Most importantly, calibrate core measurements to conventional open-hole log
suites, thereby expanding knowledge regarding reservoir characterization,
formation evaluation (OGIP, Recovery and EUR) and optimization of the
hydraulic fracture stimulation
Basic Petrophysical Workflow
Core Data Xplots
TOC
Porosity
Permeability
Saturation
Lithology
Geomechanics
ALGORITHMS
Interpreted
Log Curves
Cluster Analysis
Facies Classification
Core to Log Calibration: TOC-Porosity-Permeability
Triple Combo
TOC
TOC/RHOB
Fair correlation coefficient
r2 ~ 0.65
Ø-Total
RHOB
1
2
3
4
HC-filled
porosity
4
Ø-HC
Max Perm
6
Porosity
Highest correlation coefficient
r2 ~ 0.93
Total
porosity
Permeability
Least dependable of the algorithms
(use qualitatively and in localized zones)
Ø-HC
5
Sw based
on default
Rw ~ 0.025
Core to Log Process: Expanding the Data Set
1
2
3
GR-TOC
RES
4
5
PORO-PERM
SATURATION
6
7
8
9
1
0
1
1
1
2
LITHOLOGY
1
3
1
4
1
5
FRACTURE
PROPAGATION
Top Shale
Base Shale
TOC
distribution
Sweetspot
screening
Rock properties
from ECS-type tool should dovetail with
geomechanical descriptions
Frac properties
from DTC-DTS
1
6
An Example of Utilizing the Expanded Data Set
Facies extracted from Crossplot
YOUNG’S MODULUS
F
B
E A-2
C
D
A-1 A-3
A-4
POISSON’S RATIO
Cluster Analysis
Poisson’s Ratio vs.
Young’s Modulus
Lambda*Rho vs. Mu*Rho
(or any other attribute
combination)
A Key Aspect of Quality Shale Reservoirs:
Vertical Heterogeneity
GR
0
0
200
COREGR_
api
DEPTH
FT
PS
200
PS
K 72 SB
PS
PS
PS
K 69 SB
12750
PS
PS PS
PS
PS
PS
PS
PS
P
S
12800
K 65 MFS
PS
P
S
PS
PS
PS
12850
K 64 SB
PS
P
S
12900
PS
PS
PS
PS
BUD
A
PS
K63 SB
PS
PS
Buda
12950
P
S
PS
Courtesy of Core Laboratories
Micro-Textural Relationships: The Importance of Scale
0.5 mm
Standard 30 micron thick slide:
No apparent grain support which
would suggest poor reservoir quality
Ultra Thin (20 micron) slide:
Significant grain support which
leads to better reservoir quality
Courtesy of Core Laboratories
Depth, feet
The Importance of “Coarse”-Grained Constituents:
MINERALOGY by XRD
Eagle Ford Shale
(PC-Q #1H)
11334.0
11350.5
11366.5
11382.5
11398.0
11414.0
11430.0
11446.0
11462.0
11478.5
11495.0
11510.5
11526.0
11542.0
11558.0
11574.0
11590.0
11606.0
11623.0
Austin Chalk
Eagle Ford
Buda
0
20
40
60
80
100
Volume Percent
Qtz
Plg
Cal
Dol
Pyr
Mar
I/S
I/M
Chl
Kao
Ker
Courtesy of Core Laboratories
Eagle Ford: Mineralogical Variation Across the Trend
Maverick Basin Area
• Clay content
increases from
west to east
• Kerogen content
remains
relatively
constant
• Increase in clay
resultant from
clastic influence
of the East Texas
Basin
Hawkville Area
San Marcos Area
East Texas Area
QTZ %
20%
CARBONATE %
40%
60%
CLAY %
80%
KEROGEN %
100%
Courtesy of Core Laboratories
The Importance of Stress
Isotropic ‘Tempered’ Glass:
One extreme
Anisotropic ‘Natural’ Glass:
The other extreme
Preferred: Something in between
Courtesy of Core Laboratories
Development Process
3D Seismic Data:
Unconventional Approach is After Discovery, Not Before
•
The cost of 3D seismic data is minimal in the total field development cost, is not critical to the
exploration process
•
3D seismic data is critical in identifying faults and dip changes that could compromise the
stratigraphic targeting of a horizontal wellbore
•
Merged ~650 square miles (~1100 square kilometers) of acquired proprietary data and licensed
data in Hawkville Field
Geo-Steering:
An Important New Geoscience Skill Set

Horizontal drilling creates significant geological challenges
o Unforeseen dip changes and/or faults can cause a well to be out of zone
for a large portion of a lateral

The combination of 3D seismic data and MD to TVD Gamma Ray
correlation allows the geologist to direct the drilling operation in order for
the well to stay within the target window

The post-drill geologic interpretation of the wellbore can cause the
completion engineer to design the fracture geometry to conform to the
geology of the wellbore

The use of the geologic interpretation can be utilized with production logs
to determine which portions of the wellbore are contributing and why
Stage by Stage Fracture Stimulation Montage:
Geometric Completions vs Geologic Completions?
The Eagle Ford After Five Years
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Approximately 10,000 wells have been permitted to date with more
than 200 rigs operating and approximately 290 wells being drilled
each month
Average EUR across the play is ~450 MBOE
Risked remaining resource is estimated at 28 BBOE from over
70,000 undrilled locations
o Current B/E prices are $62/BBL rising to $100 by 2019
At B/E price below $90/BBL, EOG and BHP have remaining resource
2.2 BBOE and 1.7 BBOE, respectively, with B/E price of $62/BBL
Spacing assumptions range from 110 acres in the dry gas areas to 40
acres in the oil window
Source: ITG Energy Play Report July 24, 2013
MMCFG/D
Eagle Ford Natural Gas Production Growth 2008-2013
YEAR
Source: Texas Railroad Commission Production Data Query System
2013 thru Q1
OIL &
CONDENSATE/MBD
Eagle Ford Oil and Condensate Production Growth 2008-2013
YEAR
Source: Texas Railroad Commission Production Data Query System
2013 thru Q1
DAILY PRODUCTION
BOE/D
Eagle Ford Oil Drilling Permits 2008-2013
YEAR
Source: Texas Railroad Commission Production Data Query System
2013 thru Q1
TOTAL DRILLING
PERMITS
Eagle Ford Oil Drilling Permits 2008-2013
YEAR
Source: Texas Railroad Commission Production Data Query System
2013 Annualized from Q1
Conclusions

The Eagle Ford has proven to have all of the right
ingredients for a world class shale reservoir
o Petrophysical parameters that are among the best, if not
the best, of any known shale reservoir
o A wide range in depth (approx. 5000’-13,000’/1500m4000m) results in complete spectrum of hydrocarbon
products
o A majority of the trend is in moderate geopressure,
providing for significant hydrocarbon volumes in place
o Favorable regulatory and mineral owner environment
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These factors have lead to growth in the Eagle Ford that is
truly unprecedented