Getting the tight gas and oil out of the reservoir
Feng Zhu
James Strohaber
Alexandre Kolomenski
Tarek Hassan
Hans Schuessler
Mashhad Fahes
Ashfac Bengali
Gamze Kaya
Necati Kaya
Nathan Hart
Cade Perkins
Ricardo Nava
Aysnur Bicer
Muhammed Sayrac
Ruqayyah Aska
James Bounds
Josh Wood
Erika Cook
Jahanur Rahman
Texas A&M University
College Station/USA
Doha/Qatar
http://sibor.physics. tamu.edu
Outline
 Motivation




"Sniffing" of well gas from natural seeps and leaks in pipelines
Analyze methane in sea waters in the aftermath of the Gulf oil spill
Monitor greenhouse gases in the atmosphere from undiscovered
petroleum reservoir and released by fracking of shale gas
Measurement of carbon ratios
 Mechanics of near and far bore hole exploration
 Applications range from exploring reservoir structure to
mud logging
 Recovering the noble gas tracers for laser spectroscopy
 Initial experiments at TAMU and TAMU-Qatar
 Summary and outlook
Qatari North Field
Mechanics of near and far bore
hole exploration
Applications range from exploring
reservoir structure to mud
logging
Complete collinear fast beam laser spectroscopy apparatus at TAMU
CI
Cs cell
FI
Postacc
Lasers
A
Interaction region
Energy Filter
ion Source
Mass Resolution
B Field
N2
0
40
80
Gas (mT)
Energy Filter
FI
Ar
Stripped ions
R=m/∆m≈250
ions
Xe+
Collisional Ionization
CI
120
1.40 1.45 1.50 1.55 1.60 1.65
Voltage (×100 V)
Absorption Spectroscopy
of atmospheric air samples collected
at interesting areas
Frequency Combs
+∞
E(t)=A(t)eiωct = Σ Am e-imωrt-iωct
m=-∞
ωn = nωr + ωCE , ωCE < ωr, ∆φ=2π ωCE/ωr
Frequency comb for gas detection
Comb modes
Molecular absorption profile
Transmitted comb modes
frequency
Frequency comb
laser source
Frequency comb can provide
the advantages: - Broad
Spectral coverage with high
brightness - High frequency
precision on each comb tooth
Molecular
sample
Detection
Strong molecular absorptions in midinfrared (1.5-5 microns) - Requires
frequency comb source in mid-IR
- Requires broad detection over large comb
range
Courtesy of Scott Diddams
Multipass setup
Experimental Results
Carbon isotope ratio of methane
 Indicator used for characterization of different geological
systems: petroleum resources and oil exploration, in medical
sciences, agriculture and archeology.
 Characterizes the origin and content of different geological
systems, i.e. as coal marine, oil carrying or general biological
systems without oil components.
 Reflects the oxidation pathways of methane, providing
evidence of a thermogenic, biogenic or mixed origin of
hydrocarbon accumulation.
Determination of the carbon isotope ratio
Carbon isotope compositions are conventionally reported as
δ–values, which are defined as
δ13C = (R/Rstd - 1) × 1000 (PDB,‰) ,
where R denotes the 13C/12C ratio of the sample and Rstd is the
ratio of the Pee Dee Beliminite (PDB) standard. The PDB
standard is based on stable isotope values of Cretaceous
belemnites from the Pee Dee Formation of South Carolina.
Examples: The δ13C values of methane are about
(-20 ~ -35) ‰ in different coal marine systems, (-45 ~ -55)‰ in
subsurface biodegraded oil at marine petroleum systems, and
(-60 ~ -70) ‰ in general biological systems such as a rice
paddy.
Deepwater Horizon
Sampling Sea water in the gulf of Mexico
RV Pelican and collection apparatus
Seawater samples collected in situ 7 miles from DH
• 40 L of seawater from DH area collected in specially
cleaned containers
– 25 L from closest station (previous slide)
– 15 L from other adjacent stations
– Samples were treated with Sodium Azide to avoid
changing of methane content by bacteria
• Samples were taken from the entire water column
from ground zero (1500 m) to the surface.
Scale
Carousel Water Sampler on R/V Pelican July 2012
GERG TAMU
Shale gas basins in the United States
Shale gas formations in North America hold trillions of cubic feet of natural gas. The
U.S. has enough reserves of clean natural gas to power our homes and even our
vehicles for years to come. The shale basins shown above will be a major source of
that natural gas. According to the A.A.P.G. shale gas will account for more than 51% of
our gas supply this decade.
Hydraulic Fracturing
• Hydraulic fracturing is the process of using
hydraulic pressure to create an artificial fracture
in a reservoir
• The fracture grows in length, height and width by
pumping a mixture of hydraulic fluid and
propping agents at high pressure into the well
bore
• The purpose of a fracture is to alter the flow
pattern in the reservoir to increase the oil and
gas flow rates
Virtually impossible
Micro seismic data says no
Pinnacle paper at SPE
confirms conclusion
Courtesy of S.Holditch
Mapped microseismic height for Eagle Ford shale
• Top: shallowest microseism; Bottom: deepest microseism
• Aquifers: USGS deepest water wells by county
Deepest Water Well Depth
0
Frac Top
Perf Top
Perf Mid
Perf Btm
Frac Btm
2000
Depths (ft)
4000
6000
Atascosa
Burleson
De Witt
Dimmit
Fayette
Frio
Gonzales
Karnes
La Salle
Live Oak
Maverick
Mc Mullen
Smallest height growth at shallow depths
Webb
8000
10000
12000
14000
1
101
201
301 (sorted on 401
Frac Stages
Perf Midpoints)501
From
Pinnacle
601
701
SEAB Subcommittee Charge
Secretary Chu Tasks Environmental, Industry and State
Leaders to Recommend Best Practices for Safe,
Responsible Development of America's Onshore
Natural Gas Resources
"America's vast natural gas resources can generate many new
jobs and provide significant environmental benefits, but we
need to ensure we harness these resources safely," said
Secretary Chu. "I am looking forward to hearing from this
diverse, respected group of experts on best practices for safe
and responsible natural gas production."
Courtesy of S.Holditch
Sub-committee Documents
• You can find the 90-Day and the 180-day
Report at
http://www.shalegas.energy.gov/
• You can also find a variety of presentations
made by industry, NGOs, and government
agencies
• All meetings were video taped and are on the
website
• More that you would ever care to read
Courtesy of S.Holditch
Courtesy of S.Holditch
The next 1-2 years
Summary and outlook
Two optical tracer methods have been implemented.
First one:
 Ultra trace detection with 85Kr trace’s has been demonstrated by collinear fast beam laser
spectroscopy.
 The rare noble gases can be used as tracers to make multitrace detection possible.
 Tracers can be used in near and far borehole applications.
Second one:

Detection of methane and other greenhouse gases with near-IR fiber lasers at 1.5 - 1.7 µm and
also from 3.2-3.4 µm

The Novel multi-pass system (L = 300 m) has ppb Volume sensitivity.

Real-time dual comb spectroscopy (tmeasure = 40 µsec) can observe dynamical processes.

Analyze environmental samples in situ and collect samples at Qatar and worldwide from the
atmosphere and sea waters.
College Station,
Texas
On my laboratories, the sun never sets.
Doha,
Qatar
Meet the group (College Station, Texas)U.S.A.)
I would like to thank the following
agencies for their support and funding
Thanks to Thomas Udem, Christoph Gohle for expert advise
Tracer technology
 Tracer technology is a robust and relatively inexpensive enabling technology for
acquiring reservoir information.
 Can be used to improve water floods, well stimulation, in EOR projects, and in
chemical, gas and thermal floods.
 The interwell tracer test has proven to be an efficient tool to investigate reservoir flow
performance and reservoir properties; to reduce uncertainty attributed to well-to-well
communications, and vertical and horizontal flows.
 In the case of gas production from multiple layers (as in Qatar’s North field), a tracer
study can help to identify the amount of the gas produced from each layer.
Drawbacks of traditional radioactive tracers:
• require nuclear decay counting in well shielded facilities and long counting times.
Injecting the larger amounts of radioactive isotopes is hazardous for the operators and
requires special precautions in handling
• not sensitive enough for investigation over time periods longer than several half times.
• multi species tracer applications cannot be carried out, since only few suitable
radioactive tracer isotopes available.
In contrast, the extensions of spectroscopic laser ion beam trace analysis to other
elements with suitably chosen laser excitation steps will lead to breakthroughs in the
analysis of other trace isotopes (14C, 89,90Sr, etc.). The technique and apparatus work
equally well for the detection of all the noble gas elements in particular Kr, Xe, and
several other elements such as Sr, Ca, and Tl.
Use of tracer data in EOR of reservoirs
 Typical recovery factors following primary depletion and secondary recovery rarely
exceed 40-50% of the original-oil-in- place (OOIP). The remaining unswept
hydrocarbon resources constitute the target for Enhanced Oil Recovery (EOR)
methods.
 The assessment of recovery methods largely relies on an accurate estimation of the
spatial location and distribution of the target oil and identification of the primary paths
for fluid migration within the reservoir.
 Geological and seismic interpretation can provide valuable information for the
characterization of reservoir heterogeneity, but their ability to resolve the underlying
fluid distribution is limited. Consequently, to enhance reservoir characterization studies
and thereby improve the EOR process design, interwell tracer tests are being
increasingly employed.
 During tracer tests, a suite of tracers are injected into the subsurface and are
recovered at the observation wells. Subsurface characterization based on tracer data
is quite well understood and there are many methods developed. As a first step in
these procedures, forward models based on tracer dynamics are set up.These
equations contain permeability and porosity that represent subsurface properties.
Tracer data can also be used to compartmentalize the reservoir by finding the
connected regions. Many of the inverse approaches for reservoir characterization use
stochastic descriptions of the subsurface, assuming permeability and porosity to be
random.
Tracer requirements and selection
Tracers should satisfy general conditions, they should be:
detectable at a very low concentration (parts per million).
stable at reservoir conditions.
not absorbed by reservoir rock.
environmentally benign and have minimum environmental
impact.
• water (brine) insoluble (contamination study only).
•
•
•
•
Previously halocarbon tracers, noble gas tracers were used, in
particular 85Kr.
Other suitable candidates for tracer analysis (133,136Xe, 14C, 89,90
89,90Sr, Ca and Tl isotopes). The spectroscopic technique and
apparatus developed at TAMUQ and TAMU can be extended to
these tracers too.
Typical procedure of tracer analysis
(with 85Kr as an example, mostly for far hole use)
 A small glass vial containing the 85Kr is placed on the main valve
with the gas injection input line above the vial.
 The system is closed , the gas injection line is opened,
pressurizing the system and breaking the vial releasing the 85Kr.
 The main valve is then opened and the injection resumes with the
85Kr carried into the reservoir.
 In such a "slug" injection the 85Kr tracer partitions between the
phases present but the partition factors greatly favor 85Kr
remaining in the gas phase. After injection into a central well its
chemical inactivity allows 85Kr to stay and be distributed in the
reservoir (for up to decades).
 Sampling from different locations/wells is performed enabling
analysis of reservoir parameters.
Geophysical interest is to measure Carbon isotope ratio of methane
 Indicator used for characterization of different geological systems:
petroleum resources and oil exploration, in medical sciences,
agriculture and archeology.
 Characterizes the origin and content of different geological systems,
i.e. as coal marine, oil carrying or general biological systems without
oil components.
 Reflects the oxidation pathways of methane, providing evidence of a
thermogenic, biogenic or mixed origin of hydrocarbon accumulation.
Near hole tracers: mass balance equations
(for the gas components in the mud liquid and the reservoir gas)
Wellbore
Drilling fluid
(mud filtrate),
concentr.
Xm,i – known!
For components common for the reservoir
gas and mud filtrate
Reservoir gas
with concentr.
Zi (unknown!)
Contact
and mixing
Returning mud: Liquid with partial content (1-Vf),
concentr. Xm,i and gas with partial content (Vf),
concentr. Yi; concentrations are measured during
mud logging or by collecting samples
For components that are present only in the
mud filtrate naturally (markers)
or deliberately added (tracers),
L
c
Unknowns: fraction of drilling fluid before contact, Lc, and
the vapor phase fraction after contact Vf.
Then two tracers should be sufficient to determine the original
composition of the reservoir gas.
F. Gozolpour, A. Donesh, A.C. Todd, B. Tohidi, SPE Reservoir Evaluation & Engineering, February 2007.