Reservoir and Fracturing Technology Issues in Tight Gas Development（致密气藏开发中的储层和压裂技术问题）.pptx

SPE Calgary Section
Reservoir and Fracturing
Technology Issues in Tight Gas
Development
A . (Tony) Settari
University of Calgary
TAURUS Reservoir Solutions, Calgary
With contributions from . (Bob) Bachman
TAURUS Reservoir Solutions, Calgary
Outline
• A bit of history of tight gas development
• Sampling of technology issues/advances:
– Reserves estimation
– PTA – special issues for tight gas
– Modeling
• Frac treatment analysis/optimization
– Frac length vs conductivity
– Waterfracs
– Geomechanics - Shear fracturing
• Frac monitoring and links to geophysics
• Summary
A bit of history of tight gas
• Onshore North America since the
1970’s
• Tax incentives in the US in 1980’s
spurred technology, first foray into CBM
business and shales
• Large amount of technology developed
in 1980’s:
– Driven by belief in “bigger is better” and
“adding reserves by fracturing”
• Persistent low prices in the 1990’s
– slowed R&D (with exceptions…)
– Technology packaging and user friendliness
• Current scene
– Revival of tight gas on international scale
(until summer 2008 …)
– Unconventional gas (TG, shale, CBM,…)
share rising
– Development of monitoring technology and
geomechanical aspects
jub size (lb of proppant)
90
68
86
78
94
98
00
66
70
74
82
19
20
19
19
19
19
19
19
19
19
19
20
20
04
06
A bit of history
• Schematic of the history of propped frac job
sizes (Cotton Valley, Wilcox Lobo, .)
evolution of frac size (schematic)
1,400,000
1,200,000
1,000,000
800,000
600,000
400,000
200,000
0
year
Maximum
job size
pumped: > 7
MM lb of
sand (Mobil,
GHR in W.
Texas)
Reservoir characterization
challenges
• Geology and stratigraphy
– Faulting
– Lenticular sands
– Channels plex features
– Shale/sand sequences
• Fracture characterization
– Seismic methods
– Wellbore imaging
– DFM modeling
– Production, PTA, …
• Integration of methods improves quality of
characterization
Reserves estimation
• Tight gas –