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Transcript of Buenos Aires, 7 al 10 de agosto de 2012 Environmentally Friendly Drilling Fluids for Unconventional...
Buenos Aires, 7 al 10 de agosto de 2012
Environmentally Friendly Drilling Fluids for Unconventional Shale
James Friedheim Quan GuoM-I SWACO
Shale Gas in Argentina
“Argentina is the country with the third highest geological potential for these
types of hydrocarbons (shale gas), after China and the United States”
Overview of Argentina Shale Gas Fields – (from Investment U article The Next Big Shale Gas Boom by Justin Dove, Investment U Research; Friday, October 7, 2011)
The study assessed the viability of 48 shale gas basins in 32 countries and estimated
Argentina’s shale gas reserves at 774 trillion cubic feet (TCF), 60 times greater than the country’s current conventional reserves.
Furthermore, Argentina possesses almost 12% of the global shale gas resources, with
the Neuquen Basis showing greatest potential.
- Annual Energy Outlook 2011
All Shale Not the Same!
High Reactivity Shale
• Massive structure • Lack of bedding planes
or evident laminations • Soft • Plastic • Sticky• CEC >20 meq/100g• Predominance of
Smectite
Moderate Reactivity shale
• Moderate laminated structure
• Bedding structure• Easily broken • Not plastic• CEC 10-20 meq/100 g • Presence of smectite
and Illite approximately similar proportion
Low Reactivity Shale
• Strongly laminated structure
• Fissile • Brittle (Break along
lamination) • Hard and firm
consolidation • Not sticky • CEC <10 meq/100g• Predominance of illite
Unconventional resource requires unconventional thinking
Traditional Fluids Selection Techniques May Not Apply…..
Effective and useful shale-fluids interaction tests – Shale Hydration Test, Dispersion Test, Slake Durability Test, …
These traditional shale-fluids interaction and fluids selection tests are not effective for gas shale
Shale Play – Fluid Design Each shale play is different
and fluids should be tailored for each formation
Shale plays are usually less reactive (swelling), but are micro-fractured and can be very easily destabilized by fluid or filtrate
The overburden is different Some High-Temperature
shale plays (such as Haynesville) demand temperature stability, good rheology and densities up to > 19 ppg
Marcellus Shale Core 6711.05 – 6711.6 ft
Smectite 4%
Illite 25%
Quartz 47%
Feldspar 10%
Pyrite 5%
Chlorite 6%
Ankerite 3%
CEC, (meq/100gr) 3
Permeability (nd) 19 @ 3000 psi
Permeability (nd) 6 @ 6000 psi
Porosity 10%
Total organic content 9%
Oil/Gas Shales Tend to be Hard and Organically Rich
Old Shales Still Can Be Unstable in Freshwater
Fracture Tendency Allows Water Access
OBM/SBM Still Drilling Fluid Predominately Used
• Advantages– Cost*– Readily available*– Good temperature stability– Provides good hole stability &
shale stability– Tolerates contaminants well– Low torque & drag while drilling
& running casing
• Concerns– Cost**– Availability**– Downhole losses
ConcernsEnvironmental Acceptability Toxic Compounds* Slow degradation Rates* Cuttings Disposal (except PARALAND)
Human Exposure Factors High vapor emissions Aromatic & Cyclic hydrocarbons in the
vapor, and consider carcinogenic*
*) diesel **)synthetics
Shale Gas Water-based Mud Design
Develop a low cost, environmentally friendly WBM drilling fluid (fresh water) for the shale plays
• Straight-forward, simple, cost-conscious design.
• Environmentally friendly – precludes the use of
chloride-containing materials.
• Provide shale stability to low-reactivity, fissile shale
Physical Plugging• Blocks entry of fluid into the
formation• No decrease in stability• Inert chemistry
Water invasion into the shale formations weakens the
wellbore – not so much a chemical process!– Normal fluid loss additives are not able to form a filter cake and
therefore cannot stop the invasion of fluids, especially water.
Focus more on wellbore stability than shale inhibition for long
open hole section using WBM
Address issue of lubricity for both drilling and running casing
Goal
Concept
high permeabilitythick filter cake
low permeabilityvirtually no filter cake
SMT (Shale Membrane Test)
Paper # • Paper Title • Presenter Name
Fluid at fixed flow rate and pressure
Pressurized with brine that matches the water activity
of the shale
Pressure differences ∆P(t) at top and
bottom are used to calculate permeability
properties
300 psiEpoxy
50 p
si
Top Cap
Base
Typical Test Regime1. Brine matches water
activity of the shale2. Brine/Drilling fluid3. Nanomaterial and
drilling fluid4. Can be repeated
several times
P1 P1
P2 P2
SMT Results† Atoka Shale
† ) Sensoy, T, Chenevert, M. E. and Sharma, M. “Minimizing Water Invasion in Shales Using Nanoparticles.” paper SPE 124429 presented at the 2009 SPE Annual Technical Conference and Exhibition, 4-7 October 2009, New Orleans, Louisiana.
P1 P1
P2 P2
CONFIDENTIAL INFORMATION © 2009 M-I L.L.C.
Barite – 15,000 nmWARP – 1,500 nmBarite – 15,000 nmWARP – 1,500 nmFlu virus – 150 nm
Barite – 15,000 nm WARP – 1,500 nmFlu virus – 150 nmNanoparticles – 15 nm
Silica Nanoparticle ScreeningDesign Considerations• Cost• Various coatings/treatments & Number of treatments• Reactive groups• Temperature stability• Rheology effects• Sizes 5-100 nm• Compatibility with ions in a range of concentrations Faster tests and better availability
than shale samples
5 nm 10-30 nm 40-50 nm 70-100 nm
Nanoparticle Characterization
• Cryo-Transmission Electron Microscopy (TEM) performed at Rice University
• Right image is the best performing sample• The images will be used to better understand their filtration behavior
40000x magnification, scale bar 50 nm40000x magnification, scale bar 50 nm
Optimizing Nanoparticle Loading
Full mud formulation designed for maximum efficiency
Loading reduced from 29% to 3% (10 ppb, Nanoparticle slurry)
Permeability reduction is permanent
Strong stabilization of shale by blocking fluid access
Step Test Fluid Permeability, nD Permeability Reduction, %
1 4% NaCl Brine 0.153 -
2 WBM with 3% w/v of nanosilica 0.0042 97.2%
3 4% NaCl Brine 0.0035 97.6%
General Fluid Formulation Duovis:xanthan based rheology modifier which gives us suspension properties
EMI-690sufonated styrene-butadiene copolymer with optimized fluid loss performance
Resinex:Phenol formaldehyde resin used for additional filtration control
Glydril GP 100:blend of glycols used for shale inhibition, fluid loss and baseline friction coefficient reduction
Lubricant:General purpose Lubricant for WBM, usually vegetable oil derivative
EMI-2545:Nanosilica solution for physical shale plugging
PRODUCT UNITS Concn FunctionFreshwater Vol % prn Base FluidDuovis ppb 0.75 - 1.5 RheologyEMI-690 ppb 1 - 3 Fluid lossResinex ppb 8 - 12 FiltrationEMI-2545 Vol % 3-5 Shale sealingLime ppb 0.1 - 0.3 AlkalinityGlydril GP100 Vol % 2 - 3 Filtration/lubricityBarite ppb prn DensityLube 945 Vol % 0 - 3 Lubricity
Property ValuePeriod Aged 16Temperature 150
Fann 35 viscometer data600 rpm 120300 rpm 46200 rpm 36100 rpm 246 rpm 83 rpm 610 s 610 min 8PV 28YP 18
EMS 2520
Fracture Shale Consideration
0
50
100
150
200
250
300
0 2 4 6 8 10 12 14 16
Pre
ssu
re (p
si)
Time (hrs)
Base mud
Base mud + Nano particles
Brine before mud
• Formulated drilling fluid with 10ppb nanoparticles (10% EMI-2545)
• 99% reduction in shale permeability
• Permeability reduction held after flushing with brine (88% after 6 hours)
Fracture
Additional Data on EMS 2520
Sample Medium Dosage Results (ppm)
NanoSilica Gen #7 20.0 ppb >500,000
NanoSilica Gen #7 10.0 ppb > 500,000
0 SGWBS NA 114,520
NanoSilica SGWBS 10 ppb 113,850
Effect of lubricant package seen at higher loadings
Mysid Shrimp testing both additive (nanosilica) and ShaleGas Drilling Fluid easily pass
LC50 protocol
Environmental Testing
Summary
Novel approach to shale stabilization specifically focused on Unconventional Shale Plays source Rock by physical plugging of Shale Pores utilizing Nanoparticles:
Provides high stability Especially coupled with designed fluid formulation (EMS-
2520) even for fractured shale Environmentally designed (freshwater (without chlorides)) Applicable for HT fluids Applicability to other type of shale
Couple with chemical inhibition Robust testing protocol Performance additives for enhanced lubricity