an alternative to diesel for landing drilling operations lee conn m-i swaco can non-aqueous fluids...
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An Alternative To Diesel For Landing Drilling An Alternative To Diesel For Landing Drilling OperationsOperations
Lee ConnLee Conn
M-I SWACOM-I SWACO
Can Non-Aqueous Fluids (NAF) Be
Designed to Enhance Soil Quality?
Non Aqueous Base Fluid SelectionsBase Fluid Environmental Staircase
Diesel
Mineral Oil / EMO
Internal Olefins/Ester
Linear Alfa Olefins
Paraffin
Since the 1980’s, there has been a strong demand tocontinue to improve environmentcharacteristic of base fluidsbeing used offshore
Environmental Testing Protocols & Regulations Established
Primary Drivers for Base Fluid Selection
• Environmental - Regulatory compliance- Seabed impacts
• Commercial - Cheaper Base Fluids- Availability - Logistics
• Technical- Lower Viscosity
Comparison of Base Fluids
Base Fluid Density KV @ 40°C Flash Point HTS Biodegradation
(SG) (cSt) (°C) (°C) Aerobic Anaerobic
Desirable < 0.80 ALAP > 95 AHAP Yes Yes
Mineral Oil 0.790 2 - 3 > 95 > 200 ? No
LAO 0.776 2.26 113 > 200 Yes Yes
PAO 0.800 5 - 7 160 High Yes Yes
Ester 0.850 5 - 6 > 150 150 Yes Yes
Internal olefin 0.792 3.60 > 138 > 204 Yes Yes
Linear paraffin 0.773 2.50 > 100 > 170 Yes Yes
Land Drilling OperationDiesel Still The Base Fluid Of Choice Globally
Advantages
• Diesel oil is the cheapest
• Diesel oil is more readily available
• Diesel oil has good temperature stability
• Diesel oil provides good hole stability
• Diesel oil tolerates contaminants as well
Disadvantage
• Environmental Acceptability- Toxic Compounds- Slow degradation Rates
• Poor Human Exposure Characteristics- High vapor emissions- Aromatic & Cyclic
hydrocarbons in the vapor, and consider carcinogenic
Waste Management Hierarchy
Reduction at SourceReduction at Source
Recycle & ReuseRecycle & Reuse
RecoverRecover
TreatmentTreatment
ResponsibleResponsibleDisposalDisposal
Long Term Liability
Drilling Fluids & Waste Management Options
Waste Management / Disposal Options For NAF Cuttings
• Thermal- Incineration- Indirect heat for base fluid recovery (re-use base
fluid)
• Injection
• Haul to registered disposal site
• Cuttings treatment- Stabilization, bury on site
• Bioremediation
Non Aqueous Fluid (NAF) Design StrategyObjective – Creating a Soil Enhancing Product
• Identify - environmental issues with
traditional formulations- root causes in the chemistry
of the additives- products that enhance rather
than damage the environment
• Build a cost effective and technically competent mud system based on selected additives
• Design a cost-effective and dependable bio-remediation process that will meet a consistent environmental performance standard
Testing for Land TreatmentTesting for Land Treatment
Diesel
Environmental Issues With NAF SystemsReview of Drilling Fluid Components
Hydrocarbon Base Fluid Chemical Structure
• Aromatics
• Cyclic Compounds
• Olefins
• Linear ParaffinsDE
CR
EA
SIN
G T
OX
ICIT
Y
FO
R T
HE
SA
ME
Mol
. Wt.
C C C CC
C C C CC
C
C
C CC
CC C
C
C C
C
• Low molecular weight, linear structure biodegrades under aerobic conditions.
• Aromatics & cyclic more toxic than linear structures of same molecular weight.
Environmental Acceptance
Crude Oil
Diesel/MO
Linear Paraffins/Olefins
¹LTMO/²EMO/ Iso-Paraffins
1 Low toxicity mineral oil2 Enhanced mineral oil
HighlyBiodegradable
Slow and incompletebiodegradation
DecreasingToxicity
Bioremediation of diesel
GC/MS Diesel GC/MS Diesel after bioremediation
Incomplete Degradation Non degradable toxic residuals
Increased probability of future environmental liability
Bioremediation of mineral oil
10.00 20.00 30.00 40.00 50.00 60.00 70.000
5000000
1e+07
1.5e+07
2e+07
2.5e+07
3e+07
3.5e+07
4e+07
4.5e+07
Time-->
AbundanceTIC: IPAR-3.D
C19
C18
C17
C15
C16
C14
MO/EMO- Aromatics are removed and many normal paraffins are branched. - While less toxic than diesel they biodegrade slower than diesel.
Unresolved hydrocarbon isomers, including cyclic and branched hydrocarbons.
Bioremediation of linear paraffinsBioremediation of linear paraffins
GC/MS Linear Paraffins GC/MS Presence of hydrocarbons after bioremediation
Complete degradation No toxic residuals
Composting Results using Various Base Fluids
• LP concentrations fell from 13% to ~1% in 10 days.
• EMO concentrations did not fall significantly over 20 days
• LTMO concentrations fell to 5.5% after 20 days.
• Linear components of diesel fell to 3.3% after 20 days with much slower subsequent degradation.
Total HC Content
02468
10121416
0 5 10 15 20Time, Days
Hy
dro
ca
rbo
n
Co
nc
en
tra
tio
n,
%
Biobase 560 DF1 EDC95-11 Diesel
LP LTMO EMO
Base FluidBiodegradation & Toxicity Testing
Biodegradability of Various Base FluidsTreatment % Reduction of
HydrocarbonsBiodegradability Rank
C11-14 LP 97 1C12-17 LP 94 2Ester 91 3Isomerized Tetradecene C14 (IO) 83 4Diesel 61 5Branched Paraffin 43 6
Chloride
Diesel
Environmental Issues With NAF SystemsReview of Drilling Fluid Components
Internal PhaseInternal Phase
• Plant Toxicity
• Water Column Toxicity
Toxicity due to the high concentration of chlorides Toxicity due to the high concentration of salts
• Electrical Conductivity
• Lack of Biodegradation
Chlorides Are The Main ConcernChlorides Are The Main Concern
CMA gives optimal environmental performance with minimal residual conductivity. Acetates and Nitrates enhance soil productivity with minimal water column toxicity.
INTERNAL PHASE - Fluid Design Concept
TOXICITY OF DRILLING FLUIDS
0
20
40
60
80
100
120
ALFALFA GROWTH
% O
F R
EF
ER
EN
CE
EMERGENCE (%)
ROOTH LENGTH(cm/plant)
SHOOT MASS (mgdw t/plant)
Chloride
BariteDiesel
Environmental Issues With NAF SystemsReview of Drilling Fluid Components
Weighting Agent
• Barite does not enhance the quality of the soil where cuttings may be used for landfarming
• Hematite or Ilmenite promises to enhance the quality of iron poor soils, or with CaCO3 that can minimize issues with heavy metals and can be beneficial for plant growth.
Non Aqueous Fluid (NAF) For Land Drilling Non Aqueous Fluid (NAF) For Land Drilling Operation The SolutionOperation The Solution
- Unique Invert emulsion fluid designed solely for improved cleaning and remediation of contaminated cuttings
- Design to meet environmental discharge regulations (with correct processing) and improves HSE
- Recommended Fluid Design:
• Linear Paraffin or Linear Olefin
• CMA, KAc, or CaKNO3• Hematite, Illmenite, or
CaCO3
NAF-Land has standard mud properties similar to those of typical Synthetic- and Oil-Based Muds
History of SuccessHistory of Success
• Primary: Enhance production in tight gas sands
Sandstone has < 10 md permeability
Sensitive to WBM due to high clay content
• Secondary: Improve drilling performance
Stabilize shale units to reduce risk of hole problems experienced in previous wells
Cavings, ballooning, loss circulation, stuck pipe, side-tracks, well-abandonment
Sensitive to WBM due to high clay content
New Zealand Land Drilling OperationsDrivers For Fluid System Change
1 Must be a synthetically produced base fluid
“oil” has poor environmental image
lower toxicity usually associated with synthetics
Optimize environmental factors
high aerobic biodegradability
low toxicity
chlorides free
Low health & safety risk
avoid low flash points base fluids as they are classified as flammables
Field compatible mud properties of high mud weight fluid
avoid high viscosity => high ECD’s => loss circulation
Selection Criteria For Invert Emulsion
• Utilizing a combination of best available technologies / experience for system choice.
Internal phase + Continuous Phase
Nitrates Linear Paraffins
Experienced Based System
• Intervals : 16", 12.25", 8.5"
• MW : : 11.5 ppg - 16.0 ppg
• SWR : 80/20 - 85/15
• PV : 22 - 27 cps
• YP : 17 - 13 lb/100sq.ft
• Aw : 0.8 - 0.7
• ES : 400-600 volts
• HTHP FL : 1.0-3.0 mL
Mud Properties & Drilling Performance
1500
2000
2500
3000
3500
4000
4500
5000
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55Days
Dept
h
Well 3WBM
Well 3STSBM
Rig-Site Handling of Cuttings
Blending with sawdust => haul-off
Disposal Method – Vermiculture BioremediationDisposal Method – Vermiculture Bioremediation
• Worm farm already established
• Still active today for processing drill cuttings received from land operation
• The end product of vermiculture is sold as fertilizer
Bangladesh - Landfarming
• Location- Tea plantation - Rice plantation
• Drilling fluid- Base – linear paraffin with
traces of branched molecules
- Acetate Internal Phase- barite
• Designated area protected by earthen barriers
Bangladesh - Landfarming
• Management- Organic material: rice hulls- Use of local work force- Frequent tilling to guarantee aeration of the soil- Use of fertilizers
Bangladesh - Landfarming
• Site Closure
- Reduction in TPH to 1% according to internal standards and best practices
- Area covered with local vegetation
- Duration of project: 6 months
- Total volume of cuttings treated: 3000 m³
Bio-remediation processes using Diesel can necessitate long time (1-3 years) and/or large land mass to meet regulations.
Changing the fluid formulation to an optimized highly degradable, low toxicity NAFdecrease remediation timesreduce environmental impact. Lower health & safety risk to personnel
Bioremediation processes have to be optimized for local conditions.
Summary