Nano Technologies for Improved Oil & Gas Recovery

Report
Nano Technologies for
Improved Oil & Gas
Recovery
Nanoparticle perspective….
SARS virus
human T-cell
lymphotropic
virus
Nano Scale Chemical Delivery System
for Oil & Gas Applications*
•
•
•
•
•
Evolved from drug delivery technologies developed in
pharmaceutical industry.
Using nanoparticles (polyelectrolyte complexes) to entrap oil & gas
field chemicals.
Able to penetrate deep into formation rock (particle size in nanometer
range).
Change of nanoparticle surface charge by altering mixing sequence.
Controlled release of chemicals achieved by engineering
compositions of nanoparticles.
* KU Patent Pending
Potential Applications for
Oil & Gas Industry
 Any active agent capable of generating a binding event with
nanoparticles.
Examples:
• Metal ions (single and multivalent)
• Gel Breakers (Enzymes, Oxidizers)
• Scale inhibitors
• Corrosion inhibitors
• Surfactants
• Etc.
What are we looking for in
nano-carriers and other nano systems?
 Environmentally friendly
- non-toxic
- biodegradable
 Cost effective
 Compatible with hostile underground environments
- pH
- temperature & pressure
- salinity
 Compatible with reservoir rock and fluids
 Able to control propagation in reservoir rock
 Able to entrap and protect “active” during placement
 Able to control/delay the release of “active”
 Able to scale up to field scale
Example Application in
Improved Oil & Gas Recovery
 Polymer gels have been used extensively to improve sweep efficiency by
blocking high conductivity channels during enhanced oil recovery operations.
 Cr(III) crosslinks with Partially Hydrolyzed Polyacrylamide polymer (HPAM)
to form a strong gel.
 Once gelled, can no longer propagate in formation rock.
 Gelation time too short (< 30 min.) to place gel deep into formation rock.
 Polyelectrolyte complex nanoparticles can entrap and control the release of
Cr(III) to delay the onset of gelation.
Process of Entrapping Active Agents
in Nanoparticles
Polycation
Polyanion
MIX
Nanoparticles
+
Cr(III)
Cr(III)
Characterization of Nanoparticles
Sample
Cr(III) Nanoparticles
Diameter
nm
Zeta Potential
mV
Entrapment
Efficiency %
140.6±3.6
16.12±1.24
95.9
Laser Particle Size & Zeta
Potential Analyzer
Controlled Release of Crosslinking Agent
(Delay Gelation of Cr(III)-HPAM Gel)
Gelant Composition
5,000 ppm HPAM (Mw = 6,000 kDa) +
Nanoparticles loaded with 100 ppm Cr(III) +
1%(w/w) NaCl +100 ppm NaN3, pH=9.45
Gelant
HPAM
HPAM 5,000 ppm
Cr(III) 100 ppm
Nanoparticles
+
Cr(III)
Delayed Gelation of HPAM Gel Using
Entrapped Cr(III)
1050
Top of
scale
Viscosity (cp)
1000
50
40
30
40C
o
60C
o
80C
o
20
0
5 10 15 20 150 200 250
Time (h)
 Gelation time at 40 C was up to 10 days
 In contrast Control gelants consisting of 5,000 ppm HPAM and 100
ppm Cr (as CrCl3 ·6H2O) formed gels in less than 5 min
Other Example Application for
Oil & Gas Industry
Fracturing fluid cleanup
 Entrap breaker with nanoparticles and pump with fracturing fluid
 Electrostatic repulsion between like-charged nanoparticles insure
suspension and even distribution in fracturing fluid.
 Evenly distributed breaker insures effective breakdown of fracturing
fluid when released
 Breaker release can be controlled until desired elapsed time (e,g., 1
day)

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