# DRILLING MUD EVALUATION

AWMA Oil & Gas Environmental Compliance Conference May 13

- 14, 2014 Washington, PA

# PROJECT SUMMARY

• 

# Coal Bed Methane (CBM) project in Queensland, Australia

• 

# Upstream development area consists of two areas of ~3,200 mi 2



# • 

# Pipelines to LNG Plant on coast

• 

# Downstream LNG terminal for shipment

# PROJECT SUMMARY

• 

# >14,000 production wells to be drilled over ~20 years

• 

# Well depths from ~500 to 2,600 ft

# Wells spaced on 2,600 ft grid, resulting in one well per 160

acres.

# Waste Production

• 

# 200 to 250 yd 3 

# of drilling muds and cuttings produced per well

• 

# ~40% cuttings~60% liquids.

• 

# Historically, all cuttings disposed on site.

• 

# Liquids historically trucked to treatment facility or left to evaporate

# NEW WASTE MANAGEMENT REQUIREMENTS

State government requiring systematic framework for drilling waste management:

• 

# Direct reuse of surplus material

• 

# Reuse following treatment to remove impurities (recycling)

• 

# Beneficial use of liquids and solids

• 

# Disposal of liquids and solids unsuitable for other options 0% 20% 40% 60% 80% 100%

Drilling Mud Recycling Beneficial Re

- use of Water Beneficial Re

- use of Solids Burial or Disposal

DRILLING AND CUTTING VOLUMES (%) 

# Target drilling muds/cuttings management

# Study Objective

• Assess potential long

- term options for effective management of drilling wastes. 

# Approach

• Assess the potential human health and environmental risks associated with different management options and identify mitigation measures to reduce the risks.

# SCOPE OF WORK

1. 

# Review physical, chemical and toxicological properties of the drilling mud additives;

2. 

# Evaluate chemical analysis from previous drilling pit sampling and collect additional soil samples from more recent drilling sites;

3. 

# Develop conceptual exposure models and complete Persistence, Bioaccumulation, and Toxicity (PBT) analysis;

4. 

# Complete a qualitative screening assessment of concentrations to standards;

5. 

# Evaluate potential drilling mud management and beneficial use options; and

6. 

# Develop management practices to reduce risks associated with long

- term management options for drilling muds.

# DRILLING MUD COMPOSITION

• 

# Base fluid (water)

• 

# Weighting agent ( e.g barite)

• 

# Viscosifiers to remove cuttings (e.g. bentonite )

• 

# Filtration control (e.g. Lignite)

• 

# Biocide

• 

# Salts (reduce swelling)

• 

# Alkalinity and pH Control Materials

• 

# LCM material

# DRILLING MUD COMPONENT LIST Material Components Cas Number Percent Composition
Aus Plug cross

- linked polyacrylamide NA 100

Barite Quartz (silica crystalline) 14808

- 60

- 7 <3 Barium sulfate 7727

- 43

- 7 >89 Additives NA <6 Biocide G tetrakis ( hydroxymethyl ) phosphon ium sulfate 55566

- 30

- 8 18

- 25

Water 7732

- 18

- 5 remainder Caustic Soda sodium hydroxide 1310

- 73

- 2 98.4 Silica 7631

- 86

- 9 0.003 Citric Acid citric acid 77

- 92

- 9 >99
Water NA <1 Fracseal Cellulose NA 100 KCL Water 7732

- 18

- 5 35

- 80 Barite 13462

- 86

- 7 <20 calcium carbonate 13397

- 26

- 7 1

- 20 sodium chloride 7647

- 14

- 5 1

- 20 potassium chloride 7447

- 40

- 7 2

- 10 fluid loss additive NA 1

- 5 magnesium oxide 1309

- 48

- 4 <2 Viscoifier NA 0.1

- 1 Quickseal blend of sized organic fibers and fine mineral articles NA 100

RHEO

- Plug polyacrylic polymer NA >95 Salt sodium chloride 7647

- 14

- 5 97.5

- 100 Sodium bicarbonate sodium bicarbonate 497

- 19

- 8 >99

Sodium sulphide Sodium sulphide >99

# PBT (PERSISTENCE, BIOACCUMULATION, AND TOXICITY) EVALUATION

Criterion PBT Criteria 

## P For PBT purposes a chemical is considered persistent in a particular media if its half

- life in the media exceeds the following:

Half

- life (T1/2) >2 months in water

Half

- life (T1/2) >6 months in soil

Half

- life (T1/2) >6 months in sediment

Half

- life (T1/2) >2 days in air 

## B For PBT purposes a chemical is considered to be bioaccumulative if it has a BCF/BAF of >2000, or in its absence of any BCF/BAF measurement a log
Kow >4.2. 

## T For PBT purposes, in respect of aquatic toxicity, a chemical may be considered toxic under the following circumstances (corre spo nding to criteria for GHS chronic category 1:
Non

- rapidly degradable substances for which there are adequate chronic toxicity data available Chronic NOEC or ECx (for fish) <0.1 mg/L and/or Chronic NOEC or ECx (for crustacea) <0.1 mg/L and/or Chronic NOEC or ECx (for algae or other aquatic plants) <0.1 mg/L

Rapidly degradable substances for which adequate chronic toxicity data are available Chronic NOEC or ECx (for fish) <0.01 mg/L and/or Chronic NOEC or ECx (for crustacea) <0.01 mg/L and/or Chronic NOEC or ECx (for algae or other aquatic plants) <0.01 mg/L

Substances for which adequate chronic toxicity data are not available (providing criteria for P and B are met) 96 h LC50 (for fish) <1 mg/L and/or 48 h EC50 (for crustacea) <1 mg/L and/or 72 or 96 ErC50 (for alage or other aquatic plants) <1 mg/L

And the substance is not rapidly degradable and/or the experimentally determined BCF is >500 (or, if absent, the log Kow is >4.2 Toxicity to other (terrestrial) organisms Should be considered on a case by cases basis, compared with the highly toxic classifications DEWHA has developed for ag/vet chemicals Long term toxicity or evidence such as endocrine disruption effects Should be considered on a case

- by

- case basis.

# PBT SUMMARY

Product Hazard Assessment AUSPLUG Not anticipated to be hazardous to human health/environment
BARITE Not anticipated to be hazardous to human health/environment



## BIOCIDE G Liver effects (oral RfD = 0.004 mg/kg/day); very toxic to aquatic organisms.

CAUSTIC SODA Corrosive product but not anticipated to be hazardous human health/environment.

CEMENT CLASS A Product is an irritant, but not anticipated to be hazardous to human health/environment

CITRIC ACID Not anticipated to be hazardous to human health/environment
DEFOAM

- A (DG) Not anticipated to be hazardous to human health. Very toxic to aquatic organisms.

DEFOAM

- A (NON DG) Not anticipated to be hazardous to human health. Toxic to aquatic life with long

- lasting effects. FRACSEAL FINE Not anticipated to be hazardous to human health/environment
FRACSEAL MEDIUM Not anticipated to be hazardous to human health/environment

LIME Product is an irritant, but not anticipated to be hazardous to human health or environment

QUICKSEAL COURSE/FINE/MEDIUM Not anticipated to be hazardous to human health/environment
POTASSIUM CHLORIDE Not anticipated to be hazardous to human health/environment
POTASSIUM SULFATE Not anticipated to be hazardous to human health/environment

POTASSIUM SULFATE POLYMER DRILLING FLUID Not anticipated to be hazardous to human health/environment

RHEOBEN NT Not anticipated to be hazardous to human health/environment
RHEOPLUG Not anticipated to be hazardous to human health/environment
RHEOPAC

- LV/RD Not anticipated to be hazardous to human health/environment
SALT Not anticipated to be hazardous to human health/environment
SAPP Not anticipated to be hazardous to human health/environment
SODIUM BICARBONATE Not anticipated to be hazardous to human health/environment
SODIUM SULPHITE Not anticipated to be hazardous to human health/environment
XANTHAN GUM Not anticipated to be hazardous to human health/environment

# PBT SUMMARY

• 

# In general, compounds generally not considered to be persistent or bio

accumulative in the environment

• 

# Although some compounds ( eg . Biocides) are toxic or corrosive, when they are present in flow back water they will readily degrade or dissociate in the environment and will not bio

- accumulate in terrestrial or aquatic species

• 

# Salts can be mobile and exhibit phytotoxic effects

# SAMPLING PROGRAM

• 

# Collect samples from current operations

• 

# Analyze for metals, BTEX, TPH, PAHs

• 

# Evaluate historical and current results and compare to applicable standards.

# SCREENING RESULTS

ANALYTE No.
Detects Max 95% UCL 1 Residential Vapour RBSL V 2 No. > RBSL V Residential Direct Contact
RBSL DC 2 No. > RBSL DC COPC 3 (95% UCL > RBSL)
Antimony 4/78 48

- - - 31 1/78 N

Chromium 78/78 220 38

- - 100 3/78 N

Lead 76/78 333 37

- - 300 1/78 N

Benzene 27/78 16 1.5 0.8 12/78 100 0/78 N 4

TRPH C6

- C10 (minus BTEX) 37/78 90 19 60 2/78 4400 0/78 N

TRPH >C10

- C16 43/78 3170 598 330 16/78 3300 0/78 N 4

ANALYTE No.
Detects Max Detect 95% UCL 3 RBSL 1 for High Value Ecological

Areas No. > RBSL 1 Background Range RBSL ADJ 2 (adjusted for background) COPC (95% UCL
> RBSL ADJ )
Barium 27/27 400 230 330 3/27 100

- 3000 330 N Cadmium 14/27 1.7 0.37 0.77 3/27 5

- 1000 0.77 N Cobalt 27/27 16.8 11 13 6/27 2

- 40 13 N Manganese 27/27 715 443 220 15/27 850 220 Y

Vanadium 27/27 91 48 7.8 27/27 20

- 500 7.8 Y Zinc 27/27 328 77 150* 1/27 100

- 300 250

- 450 N Total Xylenes 2/27 8.4

- 1.6 2/27 n/a 1.6 Y TRPH >C10

- C16 3/27 3190

- 25 3/27 n/a 25 Y TRPH >C16

- C34 6/27 1340

- 1300 1/27 n/a 1300 N ANALYTE No.
Detects Max 95% UCL 1 No. > RBSL 2 GW
Protectio
n RBSL ADJ 2 RBSL 3 (adjusted
for

low permeabi lity mud) COPC (95% UCL

> RBSL ADJ 3 )

Antimony 11/27 0.4 0.16 2/27 0.27 2700 N

Arsenic 27/27 7.7 3.7 27/27 0.0013 13 N

Barium 15/27 400 230 2/27 120 120000
0 N

Cadmium 14/27 1.7 0.37 1/27 0.52 5200 N

Cobalt 27/27 16.8 11 27/27 0.21 2100 N

Copper 27/27 39.9 24 8/27 22 220000 N

Iron 27/27 35200 21664 27/27 270 270000
0 N

Lithium 27/27 16.1 7.7 8/27 9.3 93000 N

Manganes

e 27/27 715 443 27/27 21 210000 N

Nickel 27/27 30.2 17.3 3/27 20 200000 N

Vanadium 27/27 91 48 27/27 7.8 78000 N

Zinc 27/27 328 77 1/27 290 290000
0 N

Toluene 2/27 7.6

- 2/27 0.59 5900 N

Ethylbenze

ne 1/27 0.8

- 1/27 0.0015

15 N

ortho

Xylene 1/27 0.9

- 1/27 0.18
1800 N

meta

- &
para

Xylene 3/27 7.5

- 3/27 0.19

1900 N

Naphthale

ne 2/27 2.4

- 2/27 0.0004
7 4.7 N

TPH >C10

- C16
Fraction 3/27 3190

- 3/27 250 2500000 N

Formaldeh yde 18/24

19 7.25 18/24 0.62

6200 N 

# Ecological RBSL Screening Results Residential RBSL Screening Results (mg/kg) Groundwater Protection RBSL Screening Results

# KEY FINDINGS

• 

# TRPH C10

- C16 fractions, total xylenes, Mn , and V exceeded ecological RBSLs

• 

# No direct contact or leaching to GW standards exceeded for metals or organics

• 

# The muds and cuttings are fine

- grained , low permeability materials with organic carbon content ranging up to 2%.

• 

# The clay sized particles and salinity indicate the muds have a high cation exchange capacity, which binds metals strongly within the matrix.

• 

# High pH limits metals in pore water and the direct phytotoxic effects of individual cations (metals) as the elevated metals would not be bioavailable to plants or ecological receptors

• 

# The elevated concentrations o f salts ( NaCl and KCl ) make drilling muds unsuitable as a direct media for plant growth.

• 

# Drilling muds and cuttings do have potential benefits which will be explored...

# BENEFICIAL USE ASSESSMENT

• 

# When direct reuse of drilling mud is not an option

– beneficial use of drilling muds/cuttings is preferable to off

- site disposal

• 

# Potential beneficial uses include: land spraying as amendment, dust suppression, subgrade material for roads, blending with soil for compost.

• 

# Results of PBT and risk screening based on site specific results show potential risks to human health or the environment associated with burial or landspraying /spreading are limited

# DRILLING MUDS MANAGEMENT OPTIONS

Drilling Muds Management Options Benefits Potential Risks and Potential for Harm Mitigation and Management Measures

Direct Burial



# • Salts are isolated and encapsulated below the rooting depth of plants

• Limits impacts associated with excavation and transportation of
wastes • Phytotoxicity due to excess salts • Burial beneath root

zone

• Blending with native soils i to reduce salinity of waste materials

• Leaching of salts or metals to groundwater • Avoid shallow groundwater

• Bury waste above seasonal high groundwater levels.

• Grading to inhibit ponding

• Potential migration of CoPCs in surface
water • Project planning protocols:

• Avoid surface water bodies, cap pits as soon as practical.

# DRILLING MUDS MANAGEMENT OPTIONS

Drilling Muds Management Options Benefits Potential Risks and Potential for Harm Mitigation and Management Measures Landspreading as Amendment • Provide micro and macronutrients (K, sulphate, phosphate, nitrate) for plant growth

• Alkaline nature of the muds could eliminate the need for application of lime. • Salinity impacts on plants and soil
structure

• Potential risks to invertebrates or avian receptors from exposure to salts,
manganese, vanadium, xylenes or TPH (C6

- C10) fractions in muds. • Mixing with shallow subsoils will reduce concentrations

• Amendments (e.g. Gypsum) to reduce the SAR

• Improve water retention capacity • Potential impacts on surface water from spreading close to
water ways • Project planning protocols:

• Away from surface water

• Minimal slope

• Loading rates to mimic background

• Loading once/ yr

# MANAGEMENT OPTIONS

Drilling Muds Management Options Benefits Potential Risks and Potential for Harm Mitigation and Management Measures Dust Suppression

• Reduce dust generated during construction and operation

• Reduce use of water otherwise used for dust suppression.

• Improve road base • Potential impacts on surface water from spreading close to
water ways • Planning and operations protocols as discussed above

.

Subgrade material for road construction

• Improved road stability and bearing capacity.

• Improved compaction will limit future road maintenance activities.

• Substitute for lime and
cement • Potential for runoff into surface water

. • Planning and operations protocols as discussed above

.

Amendment in composting

• Improved water retention capacity

• Addition of micro/macro nutrients (potassium, sulfate , nitrate and phosphate) for plant growth. • Potential for leaching to surface water

• Potential for salinity based impacts to plants

• Potential for ecological impacts • Blending to reduce concentrations of salts and ensure no phytotoxic effects or impacts on ecological receptors.

• Drilling muds with very high EC and SAR should be buried or disposed off

- site.

# KEY TAKEAWAYS

• 

# In general, compounds generally not considered to be persistent or bio

- accumulative in the environment and are suitable for multiple beneficial use options

• 

# Beneficial use of drilling mud is a viable option with the following benefits:

• 

## Reduce off

- site disposal costs (all)

• 

## Provision of micro and macronutrients essential for plant growth when drilling muds and cuttings are applied as an amendment to soils ( mixbury cover and landspreading )

• 

## Improvement of the moisture retention capacity of coarse grained and highly organic soils ( landspreading

• 

## Substitution for engineered materials that are more costly and would have to be trucked to the area for engineering projects or agricultural uses (road construction)



# • 

# Mitigation measures required to manage potential impacts (e.g. mixing, amendments, and planning protocols)

# Understand your ingredient list

# THANK YOU

Thomas Silverman

Principal Hydrogeologist

EHS Support LLC

www.ehs

- support.com

Tom.Silverman@ehs

- support.com