Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 1 of 33

Paper #2-24

WASTE MANAGEMENT 

Prepared by the Technology Subgroup

of the

Operations & Environment Task Group

On September 15, 2011, The National Petroleum Council (NPC) in approving its report, 

Prudent Development: Realizing the Potential of North America’s Abundant Natural Gas 

and Oil Resources, also approved the making available of certain materials used in the 

study process, including detailed, specific subject matter papers prepared or used by

the study’s Task Groups and/or Subgroups. These Topic and White Papers were

working documents that were part of the analyses that led to development of the

summary results presented in the report’s Executive Summary and Chapters.

These Topic and White Papers represent the views and conclusions of the authors. 

The National Petroleum Council has not endorsed or approved the statements and 

conclusions contained in these documents, but approved the publication of these

materials as part of the study process.

The NPC believes that these papers will be of interest to the readers of the report and

will help them better understand the results. These materials are being made available

in the interest of transparency.

The attached paper is one of 57 such working documents used in the study analyses. 

Also included is a roster of the Subgroup that developed or submitted this paper. 

Appendix C of the final NPC report provides a complete list of the 57 Topic and White 

Papers and an abstract for each. The full papers can be viewed and downloaded from

the report section of the NPC website (www.npc.org).
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 2 of 33

Technology Subgroup

Chair

J. Daniel Arthur Managing Partner ALL Consulting

Assistant Chair

H. William Hochheiser Senior Energy and 

Environment Manager

ALL Consulting

Members

Mark D. Bottrell Manager – Field, Eastern 

Division

Chesapeake Energy 

Corporation

André Brown Associate W. L. Gore & Associates, 

Inc.

John Candler Manager, Environmental 

Affairs

M-I SWACO

Lance Cole Operations Manager Petroleum Technology 

Transfer Council

David DeLaO Manager, Drilling 

Engineering, Southern 

Division

Chesapeake Energy 

Corporation

Larry W. Dillon Completions Manager, San 

Juan Business Unit

ConocoPhillips

Donald J. Drazan Chief – Technical 

Assistance Section, Bureau 

of Oil and Gas Permitting 

and Management, Division 

of Mineral Resources, 

Department of 

Environmental Conservation

State of New York

Maurice B. Dusseault Professor of Geological 

Engineering, Department of 

Earth & Environmental 

Sciences

University of Waterloo

Catherine P. Foerster Commissioner Alaska Oil & Gas 

Conservation Commission

Linda Goodwin President DOT Matrix Inc.

Edward Hanzlik Senior Consultant, 

Petroleum Engineering, 

Heavy Oil & 

Unconventional Resources

Chevron Energy 

Technology Company

Ron Hyden Technology Director, 

Production Enhancement

Halliburton Company
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 3 of 33

Jake Jacobs Environment, Health and 

Safety Advisor

Encana Oil & Gas (USA) 

Inc.

Valerie A. Jochen Technical Director, 

Production Unconventional 

Resources

Schlumberger

Bethany A. Kurz Senior Research Manager, 

Energy & Environmental 

Research Center

University of North Dakota

Matthew E. Mantell Senior Environmental 

Engineer 

Chesapeake Energy 

Corporation

John P. Martin* Senior Project Manager, 

Energy Resources R&D

New York State Energy 

Research and Development 

Authority

Dag Nummedal Director, Colorado Energy 

Research Institute

Colorado School of Mines

Jerry R. Simmons Executive Director National Association of 

Royalty Owners

Steve Thomson Manager, DeSoto Water 

Resources

Southwestern Energy 

Company

Denise A. Tuck Global Manager, Chemical 

Compliance, Health, Safety 

and Environment

Halliburton Energy 

Services, Inc.

Mike Uretsky Member, Board of Directors 

Executive Committee

Northern Wayne Property 

Owners Alliance

John A. Veil** Manager, Water Policy 

Program, Argonne National 

Laboratory

U.S. Department of Energy

Donnie Wallis Manager – Regulatory 

Affairs, Air Programs and 

Design

Chesapeake Energy 

Corporation

Chris R. Williams Group Lead, Special 

Projects, Environment, 

Health and Safety

Encana Oil & Gas (USA) 

Inc.

Ad Hoc Member

Douglas W. Morris Director, Reserves and 

Production Division, Energy 

Information Administration

U.S. Department of Energy

 

 * Individual has since retired but was employed by the specified company while 

participating in the study.

 ** Individual has since retired but was employed by the specified company while 

participating in the study.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 4 of 33

Table of Contents

ABSTRACT........................................................................................................................ 5

THE ROLE OF WASTE MANAGEMENT IN OIL AND GAS EXPLORATION AND 

PRODUCTION................................................................................................................... 7

BACKGROUND ON DRILLING WASTES..................................................................... 7

DESCRIPTION OF THE TECHNOLOGY ....................................................................... 9

A. Many Different Options for Managing Drilling Wastes............................................ 9

B. Historical Waste Management Technology Drivers................................................ 14

C. Timeline of E&P Waste Management ..................................................................... 15

VARIATIONS BASED ON RESOURCE TYPE AND LOCATION ............................. 22

ENVIRONMENTAL BENEFITS .................................................................................... 25

OUTLOOK FOR DRILLING WASTE MANAGEMENT.............................................. 27

A. Innovation and Future Use....................................................................................... 27

B. Barriers and Opportunities....................................................................................... 28

C. Long-Term Vision.................................................................................................... 28

FINDINGS........................................................................................................................ 30

REFERENCES ................................................................................................................. 32
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 5 of 33

ABSTRACT

Waste management technology is a critical element of successful drilling and production 

operations. Proper application of waste management principles is required for both 

efficient drilling operations and environmental protection. Use of any given wastemanagement approach will continue to be decided by the interplay of economic, technical 

and operational barriers.

During drilling the largest potential waste stream is used drilling fluids and cuttings that 

are produced while drilling the well. Options for handling the fluids and cuttings, or 

“muds”, can be organized into a three-tiered water-management or pollution-prevention 

hierarchy:

• Tier 1 – Minimization: The generation of waste is minimized within the 

processes for drilling a well. This approach is mutually beneficial across all three 

objectives of minimizing the cost of drilling the well, meeting the technical of the 

drilling operation and minimizing the impacts on the receiving environment. 

When feasible, inhibitive drilling fluids and efficient mechanical solids-control 

equipment can often save money for operators and results in greater protection of 

the environment.

• Tier 2 – Recycle/Reuse: For the drilling fluid and cuttings that cannot be 

managed through water minimization approaches, operators can plan for reuse or 

recycling of drilling byproducts. The most common ways to reuse drilling fluids 

is to re-deploy them at another drilling location or at least to recover the most 

valuable constituents of the drilling fluids from one location and move them to 

another drilling location. Substantial efforts are ongoing to develop economic 

methods to treat drilling fluids and drill cuttings so that 

• they can be beneficially reused in oilfield and non-oilfield applications.

• Tier 3 –Disposal: When drilling waste cannot be managed through minimization, reuse, 

or recycle, operators must dispose of it. 

Four main lines of technology have been developed to address drilling waste management which 

is centered on handling muds that can include water, oil and certain chemical additives:

• Thermal treatment uses heat to separate more objectionable components from less 

objectionable components based on differences in volatility. It is a common process 

applied to oil-based mud and cuttings where centralized processing is feasible and 

disposal options are available for the objectionable residuals. 

• Injection technology sends treated or untreated waste streams underground into geologic 

formations that can accept and safely isolate the waste. If geology and regulations 

permit, injection can serve to substantially simplify waste management while also 

reducing the surface footprint.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 6 of 33

• High-order beneficial reuse on land comprises a combination of bioremediation and redeployment of treated wastes as soil amendments. It is most readily applied to waterbased muds although variations have been developed for some synthetic-based muds. 

• Lower-order beneficial includes re-deployment as construction aggregates. The 

treatment criteria for aggregate use can focus more on stabilization rather than complete 

remediation so that the stabilized waste is rendered environmentally inert.

Future waste-management technologies and practices most likely will find growing attention 

on biodiversity protection; changing energy policy with increasing focus on greenhouse gas 

emissions; progressively more difficult drilling environments such as offshore deepwater, 

Arctic conditions and extended-reach wells; and reduced landfill space available for waste 

disposal with implied greater reliance on beneficial reuse options.

. 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 7 of 33

THE ROLE OF WASTE MANAGEMENT IN OIL AND GAS 

EXPLORATION AND PRODUCTION

Waste management plays a role in the process of drilling a well as the drilling fluid circulates the 

cuttings from the wellbore, then as the fluid and cuttings are managed during and after their

surface return and finally after the drilling has been completed and the cuttings and fluids are 

further processed or sent for disposal. As the evaluation of drilling waste has progressed, a 

larger view of drilling waste management has grown to incorporate a larger view of management 

activities. In addition to historical focus on drilling muds and cuttings management, the impacts 

on associated air pollution, resource management, and biodiversity protection has evolved waste 

management into a broad-based evaluation of all wastes associated with drilling and producing 

wells.

During drilling the largest potential waste stream is used drilling fluids and cuttings. During 

hydrocarbon production, the largest potential waste stream is produced water. The operational 

source of the drilling fluid and cuttings waste is the uphole return of drilling mud with entrained 

rock cuttings that are produced while drilling the well. The cuttings are generated by the drill bit 

and tend to break apart as they are transported to the surface. Drilling fluids are circulated 

downhole to capture and lift the cuttings to the surface where they are removed with mechanical 

separation equipment. The residual cuttings that cannot be removed from the drilling fluid 

become entrained into the drilling fluid as fine solids. In order to manage the buildup of fine 

solids, drilling fluids are diluted with fresh volume of base fluids. Excessive volumes of drilling 

fluids contaminated with fine solids become waste. 

According to an American Petroleum Institute (API) waste survey, the exploration and 

production segment of the U.S. oil and gas industry generated more than 360 million barrels 

(bbl) of drilling wastes in 1985 (API, 2000). The report estimates that 28% of drilling wastes are 

sent to offsite commercial facilities for disposal (Wakim 1987). A similar API study conducted 

ten years later found that the volume of drilling waste had declined substantially to about 150 

million bbl (API, 2000). While there are other sources of waste generated at the drill site, this 

paper will focus the generation and management of drilling fluids and cuttings from drilling 

operations. 

BACKGROUND ON DRILLING WASTES

Before addressing the array of waste management strategies and technologies, it is important to 

understand the nature of drilling wastes and the process that generates the waste. 

Drilling fluids, solids-control equipment and the drilling fluid circulation system all are critical 

parts of the drilling operation. Drilling fluids (sometimes call drilling mud) consist of a 

continuous liquid phase and additives which modify the properties of the fluid to achieve better 

performance. The critical functions of drilling fluid include removing cuttings from the well, 

maintaining wellbore stability, cooling and lubricating the bit and controlling subsurface 

pressure. Once the drill cuttings are carried to the surface by the drilling fluid, they are separated 

from the fluid using mechanical solids-control equipment. Once the drill cuttings are removed, 

the drilling fluid can be re-circulated down the drill pipe. Depending on the geologic formation, 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 8 of 33

environment, application and well objectives, drilling fluid systems are customized to meet 

performance requirements.

Water-based drilling muds (WBMs) use water or brine as the continuous or external phase with 

the critical functions (density, viscosity, filtration, lubricity) achieved with the addition of 

various materials. Non-aqueous systems use non-water-soluble base fluid as the continuous 

phase with water (or brine) emulsified and dispersed in the base fluid. Non-aqueous drilling 

fluids (NAFs) include diesel, mineral oils, low-toxicity mineral oils (LTMOs), and synthetic base 

fluids. Studies in the North Sea and elsewhere in the 1980s, raised concerns about the 

environmental effects of the original high aromatic content of diesel fluids which drove the 

introduction of LTMOs and ultimately the development of synthetic-based muds (SBMs) in the 

1990s. The SBMs were developed to have the same performance as oil-based muds (OBMs) but 

with a lower environmental impact and enhanced worker safety through lower toxicity, 

elimination of polycyclic aromatic hydrocarbons (PAHs), faster biodegradability, and lower 

bioaccumulation potential (Neff et al., 2000). 

In selecting a drilling fluid one must consider the formations that are being drilled through (e.g., 

whether there are unstable shales present), the wellbore complexity (e.g., whether the hole is 

vertical, directional or extended reach), casing design, and pore pressure analysis. While WBMs 

maintain an important role in many drilling operations, NAFs offer a number of technical 

advantages over WBMs in difficult drilling situations (such as extended reach or drilling of hightemperature/high-pressure wells). 

As compared to WBMs, NAFs inhibit shale hydration, consequently wellbore stability is 

maintained. NAFs are intrinsically lubricious; therefore, the ability to drill highly deviated (nonvertical) extended-reach and horizontal holes is enhanced over that with WBM use. In addition, 

NAFs are generally more stable in high-temperature applications such as those encountered in 

deep wells. Furthermore, NAFs are less susceptible to the formation of gas hydrates that might 

potentially occur during deepwater drilling operations. As a result of those characteristics, NAF 

use allows faster drilling rates and results in fewer drilling problems. Faster drilling also assures 

fewer rig days (less cost and emissions) and reduces health and safety risks to personnel. In 

addition, better wellbore maintenance with NAF use results in reduced quantities of waste solids. 

Despite their high performance, there are limitations to NAF use. Those limitations include their 

cost, limitations on the fluid physical properties particularly in cold-water applications, reduced 

logging quality over WBMs, the high cost of lost circulation problems, and environmental 

concerns associated with NAF disposal. 

Owing to the minimal technical demands, low-cost WBMs typically are used in the upper 

sections of most wells. As the well deepens, and/or becomes directional, the technical demands 

increase proportionately, necessitating displacement with either a specialized water-based system 

or a non-aqueous drilling fluid. 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 9 of 33

Environmental regulatory considerations play a significant role in both the selection of drilling 

fluids and the overall economics of drilling a well. The specific regulatory requirements of an 

area often dictate the technologies that can be used and what, if any, material can be discharged 

into the environment (EPA, 1999). This, in turn, influences what and how wells can be drilled. 

The ability to discharge NAF cuttings significantly expands the inventory of wells that can be 

economically drilled in an area. 

While it is not possible to describe drilling waste using a single set of chemical properties and 

concentrations, several groups of constituents are present in most types of drilling waste. The 

major constituents of concern in produced water are: 

• Salt content (expressed as salinity, total dissolved solids, or electrical conductivity).

• Oil and grease (this is an analytical test that measures the presence of families of organic 

chemical compounds).

• Various natural inorganic and organic compounds or chemical additives used in drilling 

and operating the well that may have some toxic properties.

• Solids generated from the drill cuttings.

DESCRIPTION OF THE TECHNOLOGY

A. Many Different Options for Managing Drilling Wastes

The characteristics of drilling waste water vary from location to location and over time. 

Different locales have different drilling conditions, regulatory/legal requirements, receiving 

environments, and infrastructure. As a result, no single waste management technology or 

technique is used at all locations. Many different technology options are available that can be 

employed at specific locations. Selection of a management option for waste management at a 

particular site varies based on: 

• The nature of the technical requirements of the drilling operation.

• The economics of drilling the well and managing the associated byproducts.

• The environmental requirements for a receiving environment and regulatory structure 

perspective.

Much of the information for this paper is derived from the Drilling Waste Management 

Information System (DWMIS) website, developed by Argonne National Laboratory (ANL) for 

the US Department of Energy (DOE). DWMIS currently is housed as part of the website for 

DOE’s and ANLs information transfer system (ANL, 2011). 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 10 of 

33

Drilling waste management technologies and strategies can be organized into a three-tiered 

water-management or pollution-prevention hierarchy (i.e., minimization, recycle/reuse, and 

disposal). Examples of technologies and practices for each group are shown in Tables 1-5. 

Tier 1 – Minimization. In the waste minimization tier, the generation of waste is minimized 

within the processes for drilling a well. This approach is mutually beneficial across all three 

objectives of minimizing the cost of drilling the well, meeting the technical requirements of the 

drilling operation and minimizing the impacts on the receiving environment. When feasible, 

inhibitive drilling fluids and efficient mechanical solids-control equipment can often save money 

for operators and results in greater protection of the environment. Examples of waste 

minimization approaches and technologies are shown in Table 1.

Table 1.— Water Minimization Technologies.

Approach Technology Pros Cons

Drilling Mud and Cuttings

Reduce the 

volume of drill 

solids entering 

the wells 

Smaller diameter 

casing programs

Reduced cost of casing and 

less volume of drill cuttings

Difficult to use on deep holes 

where multiple casing strings are 

required. Less volume capacity for 

producing the well.

Inhibitive waterbased drilling fluidsReduces degradation of 

cuttings and reduces wellbore 

instability. Increases rate of 

penetration. Use of advanced 

products encourages 

additional research

Shale inhibitor chemistry is 

expensive and adds either 

organics or salts to the drilling 

byproducts. Proprietary chemical 

ingredients generate public 

uncertainty about unknown 

potential hazards. 

Oil-based drilling 

fluids

Reduces degradation of 

cuttings and reduces wellbore 

instability. Increases rate of 

penetration.

Typically requires additional wastemanagement processing, Some 

OBMs contain toxic organics.

Synthetic-based 

drilling fluids

Reduces degradation of 

cuttings and reduces wellbore 

instability. Increases rate of 

penetration.

Expensive base fluids and 

alternative internal phases are 

frequently cost-prohibitive. 

Using Drilling 

Fluids and 

additives with 

lower 

environmental 

impacts

New drilling fluid 

products that 

remove a 

recognized 

environmental 

hazard such as 

heavy metals, salt 

or oil

Removal of environmental 

hazard from the product 

removes or deduces the 

concentration of the hazard in 

the drilling fluid waste.

Some constituents that have 

environmental hazards are 

extremely effective products that 

are required for efficient drilling.

New drilling fluid 

systems targeting 

drilling fluid 

products that act 

together to achieve 

better performance

Can increase drilling 

efficiency, reduce cost and 

improve environmental 

performance

Can be cost-prohibitive. 

Proprietary chemistry can result in 

public concerns about unknown 

chemistry.

Alternative 

weighting agents 

Higher solids-control 

efficiency, lower trace metal 

Increased cost.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 11 of 

33

Approach Technology Pros Cons

Alternatives to 

traditional use of 

barite either by 

changing the size 

of the particles or 

the chemical 

makeup

content.

Improve 

mechanical 

solid control 

efficiency

Shale shakers Advanced technology 

promotes high removal 

efficiency

Advanced performance is 

ineffective in situations where 

cutting size degrades in the 

wellbore

Cuttings dryers and 

drying shakers

Secondary treatment for OBM 

and SBM cuttings reduce 

retention on cuttings

Ineffective on water-based mud 

cuttings due to shale hydration 

issues.

Screens and screen 

selection 

Improved removal of solids 

from drilling fluids

Screen improvements required 

new shale shakers to take full 

advantage of increased 

performance.

Hydrocyclones, 

mud cleaners and 

other secondary 

solids-control 

equipment

Advanced technology 

promotes high removal 

efficiency

Advanced performance is 

ineffective in situations where

cutting size degrades in the 

wellbore

Centrifuges Advanced technology 

promotes high removal 

efficiency

Low treatment volumes and 

removes drilling fluids additives 

along with the solids

Mud tanks and 

reserve pit settling 

basins

Simple and low-cost 

alternatives

Inefficient and frequently 

generates large volumes of waste.

Closed-loop 

secondary 

treatment 

systems for 

drilling fluids

Chemically 

enhanced fine 

solids separation 

equipment

Recovers water from drilling 

fluid contaminated with fine 

solids

Requires additional equipment and 

costs

Drilling Practices

Directional 

drilling

Extended reach, 

horizontal drilling 

multiple laterals

Reduced volume of cuttings 

and other waste by increasing 

efficiency

May be impractical in some 

locations and can increase cost.

Drilling smaller 

diameter 

wellbore 

Closer spacing of 

successive drill 

strings, slimhole 

drilling, coiled tube 

drilling

Smaller wellbore produces 

less waste.

Reduces production volumes in 

some cases.

Pneumatic 

Drilling

Use of air or other 

gases to as the 

drilling fluid

Removes need for drilling fluid 

and reserve pit

Not applicable in many areas.

Advanced 

drilling fluid 

containment 

systems

Pipe wipers, mud 

vacuum systems, 

mud buckets 

designed to reduce 

spills on the rig 

floor.

Effective reduction of drilling 

fluid loss

Does not address fine solids 

buildup and can lead to 

contamination of drilling fluids.

Advanced Reducing Effective product delivery into Advanced product delivery 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 12 of 

33

Approach Technology Pros Cons

drilling fluid 

product delivery 

systems

packaging waste 

though bulk 

product delivery 

systems reduces 

solid waste

mud systems improves

efficiency. Packaging waste 

such as drums and empty 

sacks are a major waste 

stream

systems increase cost and are not 

applicable in some situations.

Advanced 

communication, 

analysis, and 

wellsite 

engineering

Effective and 

efficient use of 

available 

technology 

improves both 

drilling efficiency 

and waste 

minimization

Computer-based data 

acquisition improves 

information transfer and 

analysis so only the 

necessary products are used.

Over-reliance on technology 

diminishes sensitivity to onsite 

evaluation and action to address 

problems at the wellsite.

Tier 2 – Recycle/Reuse. For the drilling fluids and cuttings that cannot be managed through 

water-minimization approaches, operators can move next to the second tier, in which drilling 

byproducts are reused or recycled. The most common way to reuse drilling fluids is to reuse 

them at another drilling location. Another common technique is to recover the most valuable 

constituent of the drilling fluids with mechanical separation equipment (barite and base fluids) 

and reuse them on another drilling location.

Substantial efforts are ongoing to develop economic methods to treat drilling fluids and drill 

cuttings so that they can be beneficially reused in oilfield and non-oilfield applications. Some of 

those treatment options are also used for treatment prior to disposal of the residual byproducts 

which are discussed in the next section. Examples of water reuse and recycle management 

options and some of the specific uses are shown in Table 2.

Tier 3 –Disposal. When drilling waste cannot be managed through minimization, reuse, or 

recycle, operators must dispose of it. Table 3 lists water disposal technologies.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 13 of 

33

Table 2. Drill Cuttings Reuse and Recycle Management Option.

Management 

Option Specific Use Pros Cons

Thermal 

Incineration

Rotary Kilns Use of base fluid for energy

No residual hydrocarbons on 

cuttings.

Limited application and 

transportation of cuttings to 

offsite treatment / use. No oil or 

energy recovery.

Cement Kilns Use base fluid for energy.

Recovers energy and uses 

drill solids.

Limited slip stream to main 

cement production.

Thermal 

Desorption

Indirect rotary kilns Thermal recovery of base 

fluid.

Dust from solids and thermal 

degradation of base fluids.

Hot oil processors Thermal recovery of base 

fluid, low operating 

temperatures.

Lower throughputs. Limited heat 

transfer.

Thermal Phase 

Separation

Thermal recovery of base 

fluid, Better air emission 

controls than rotary kilns.

Cost of Unit.

Thermo Mechanical 

Distillation using 

friction

Mechanical energy, compact 

size, limited process 

temperatures, off shore 

suitability.

Cost of Unit.

Breakdown of cuttings from 

hammer mill results in solids 

carry over.

Thermal Plasma 

Volatilization

High operating temperatures 

and volume reduction.

High Cost – experimental and no 

commercial applications yet.

Bioremediation 

and beneficial 

reuse in land 

application or 

wetlands 

application

Land Farming Low treatment cost beneficial 

in some soil conditions.

Not effective for salt and heavy 

metals, requires available land 

area. 

Land spreading (one 

time)

Low treatment costs 

beneficial in some oil 

conditions. Aqueous 

solutions from reserve pits 

can help irrigate dry lands.

Not effective for salt and heavy 

metals, one-time use only

Composting Small footprint Limited to temperate regions and 

requires water.

Vermiculture Soil amendment 

production

Converts byproducts to 

beneficial soil amendment

Requires specialized drilling fluid 

and vermiculture experience.

Stabilization 

and use as a 

construction 

material

Road building sub 

base or surface

Has been demonstrated to 

meet specifications for road 

base.

Daily cover for land 

fills

Stabilized cuttings are an 

effective cover material

Other types of 

construction material

Can be used to develop drill 

pads

Solvent 

Extraction using 

Super Critical 

CO2

Treatment of drill 

cuttings and recovery 

of oil

Ambient temps. Low energy 

consumption. High oil quality 

and recovery efficiencies. 

Exploratory. No commercial unit 

available.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 14 of 

33

Table 3. Drill cuttings and drilling fluid disposal technologies.

Technology Pros Cons

Onsite burial 

(Pits, Landfils)

Low cost and simple technique. Most common 

waste management method, low toxicity 

additives prevent environmental hazards.

If waste contains high concentrations of salts and 

hydrocarbons can leach from pit and create 

environmental hazards.

Discharge to 

Ocean

WBM and SBM cuttings can be disposed 

offshore with limited environmental impact.

Discharge of OBM cuttings can lead to cuttings 

piles that are slow to degrade under seafloor 

conditions.

Commercial 

disposal facilities

Offsite treatment and disposal allows effective 

and safe disposal of wastes that can not be 

disposed of onsite due to high concentrations of 

toxic constituents.

Requires transportation and associated air 

pollution. Reduces focus on waste minimization.

Slurry Injection Onsite waste management. Requires engineering studies to protect casing 

and drinking water supplies. Limited formations 

are available for injection.

Bioremediation / 

land application

Effective treatment of organics, safe 

management of drilling fluid constituents.

Not effective on wastes with high concentrations 

of salt and oil. Requires use of land areas.

Disposal in salt 

Cavern

Effective disposal in controlled conditions. Requires transportation and associated air 

pollution. Reduces focus on waste minimization.

B. Historical Waste Management Technology Drivers

The history of development of oilfield waste management has several key drivers that continue 

to dominate the development and use of waste management strategies summarized in the 

previous sections. The first driver has been environmental compliance which has its own drivers 

of environmental science and regulatory development. Secondly, operational performance 

required to drill and produce wells has evolved driving forward new requirements for 

technology. Finally, economic performance of the waste-management technology and the 

overall exploration and production operation placed demands on technology.

Within this triad of performance, individual technologies are developed within a business 

environment that tends to by cyclic in nature. Frequently, when rig counts are high, service 

companies perform well financially and have resources to investing in research and new 

technology or new equipment. At other times, when commodity prices and rig counts are low, 

pricing for oilfield services collapses and the focus becomes using existing equipment and 

technology in the most efficient manner. Regulatory cycles can also impact the introduction of 

new technology. The need for new technology is sometimes created when a catastrophic event 

occurs. Other developments occur when discovery of an environmental hazard is revealed. 

Most commonly, a scheduled review of current practices requires systematic improvements in 

environmental performance. Figure 1 reviews the historical rig count for domestic operations

compared with a key commodity driver, namely, the price of crude oil.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 15 of 

33

Figure 1. Variation of drill-rig activity with crude oil price

Even when economic conditions are stable and regulatory conditions are stable, new technology 

is sometime required to address operational targets for the drilling operation. Deeper drilling, 

high temperatures, lower temperatures, challenging shale formations, directional drilling. All of 

these conditions require higher performance and consequently, new technology to address the 

challenges. For offshore drilling operations, the major changes have been driven. 

C. Timeline of E&P Waste Management

Table 4 summarizes the timeline of development of oil and gas drilling and associated wastemanagement technologies. In light of certain benchmark years, the timeline can be viewed as 

divisible into three main stages:

• Stage 1 (1859-1936): Creation of the industry and the earliest technologies

• Stage 2 (1939-1969): First availability of standardized drilling methods

• Stage 3 (1970-Present): Adoption of advanced and computer-assisted technologies
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 16 of 

33

In Stage 1, simple methods for drilling were used. Early circulating systems in rotary drilling 

were focused on controlling sub-surface pressures and cleaning the cuttings from the wellbore. 

Water is the primary component of drilling fluids and the process of drilling the well entrains 

solids into the water providing viscosity to help lift the cuttings from the wellbore. Two key 

components of drilling fluids that were introduced in those early years were barite and bentonite. 

Those two key additives are commonly used today and into the foreseeable future because of 

their mud-enhancing properties. Barite is a heavy mineral that adds density to the drilling fluid 

and bentonite is a swelling clay that add viscosity and provides a slick wall cake on the wellbore. 

While neither barite nor bentonite were not selected for their environmental performance, as it 

turns out, both of those key additives have low environmental impacts. Also during those early 

years, shale shakers, desanders and centrifuges were introduced to help reduce the solids loading 

in the drilling fluid system. While the shale shaker was not introduced as a waste-management 

tool, its function to remove cuttings from the base fluid serves to significantly reduce the volume 

of drilling mud that must be disposed. While some attention had been made to drilling-fluid 

performance during the early years, the evaluation of drilling fluids was not uniform. Stage 1

ended with the introduction of a uniform practice of drilling fluid evaluation from API. Early 

environmental concerns focused on control of blowouts and production. Most waste 

management was conducted onsite and involved simple techniques such as storage in pits and 

burial

During Stage 2, drilling fluids and solids control evolved to meet new challenges. Those 

challenges generally evolved in two types of drilling environments. Along the Gulf of Mexico 

coastal region and in other areas, the drilling issues focus on drilling though geological shale 

formations that hydrate and cause drilling problems. Those formations have many technical 

descriptions but are known commonly as “gumbo.” In hard rock regions, the focus of improved 

drilling fluids focused on lowering the solids content in the drilling fluid so drilling could 

proceed faster. While new challenges continue to evolve, the basic structure of identifying issues 

and using drilling fluids and solids control to address them was set in place. Drilling waste 

management practices for exploration and production continued to focus on onsite management. 

Production equipment evolved to focus on maximizing production with more advanced storage 

tanks and separation equipment. As drilling moved from onshore to offshore, onsite discharge of 

spent drilling fluids, cuttings and produced water was discharged onsite.

Now within Stage 3, challenges continue to evolve and be resolved with both traditional and new 

technology. While environmental protection has always been part of E&P operations, during the 

1970s intense efforts were made across all industries to review discharges for possible 

environmental hazards. Those efforts have become an important driver in all E&P activities, 

including evaluation of existing drilling fluids, solids control and waste management practices 

with particular focus on the discharge of drilling fluids, cuttings and produced water offshore. 

Many of those studies were in conjunction with regulatory development activities driven by the 

NPDES permitting system. Those extensive studies generally concluded that the traditional 

water-based drilling fluid components such as barite and bentonite did not pose a significant 

impact to the environment. 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 17 of 

33

Table 4. Timeline of Technology Developments for E&P Waste Management.

Year

Drilling Technology Drilling Fluid SCE

Stage 1: Creation of the Industry and the Earliest Technologies

1859 1859 Drake well dug by hand

1870 First cable tool rig

1887 Chapman patent 

1890 Rotary drilling developed

1901 Spindletop, use of native 

clay fluids (gumbo)

1922 Barite first used 

1928 Bentonite first used

1929 Shale shaker introduced in

California

1930 First proprietary agent for 

thinning mud.

1931 Patent for dissolved salts 

to control shale heaving

Desander Introduced

1933 First whipstock for directional drilling Centrifuge introduced

1935 First tri-cone bit Introduction of sodium 

silicate muds to treat 

heaving shales, also shell 

began systematic research 

into oil based mud

1936 API Standard Field 

Procedure for Testing 

Drilling Fluids

Stage 2: First Availability of Standardized Drilling Methods

1939 First horizontal well drilled (Havener 

Run field in Morgan County, OH)

Introduction of salt water 

muds and starch

1942 First commercial oil based 

mud introduced.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 18 of 

33

Year

Drilling Technology Drilling Fluid SCE

1943 Rise in popularity of 

quebracho (a tree bark 

extract), high pH muds to 

thin muds and manage drill 

solids along the gulf coast

1946 Principles of Drilling Mud 

Control (training Manual)

1947 First offshore directional wells 

drilled (Gulf of Mexico)

1949 Patent for Calcium 

lignosulfonates

1953 First truly multilateral well drilled Decanting Centrifuge 

introduced, interest revived in 

desanders

1954 First hydraulic rotary rig

First directional drilling assembly

1955 Craig-Geffen-Morse waterflooding 

model developed

Benefits of low solids muds 

recognized in hard rock 

drilling

1956 First gyp-chrome 

lignisulfonate used for high 

temperature flow control 

prosperities

1959

1960 Bentonite extenders used 

to promote low solids 

drilling muds

1961 First use of dynamic positioning Chrome lignite, Chrome 

lignosulfonate widely used 

in Gulf Coast on deep 

wells and high 

temperatures.

1963 Patent application for inhibitive 

properties of potassium based 

mud systems.

1965 General recognition of the 

importance of solids control led 

to the development of more 

effective solids control 

equipment.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 19 of 

33

Year

Drilling Technology Drilling Fluid SCE

1966 Computerized well data monitoring

1967 Introduction of XC Polymer for 

low solids muds

1969 First coiled tubing rig job

Stage 3: Adoption of Advanced and Computer-Assisted Technologies

1971 Polycrystalline diamond compact bit 

introduced

2-D seismic prevalent, computers 

convert drill velocity data into 

geological information

1972 Landsat satellite becomes available 

for remote sensing

1974 3-D seismic data acquisition tested 

in Gulf of Mexico

API bulletin on Drilling Fluids 

Processing Equipment API 

Bulletin 13 C first edition

1975 First floating production system 

begins operation

First commercial 3-D seismic survey 

recorded

1978 First measurement-while-drilling 

(MWD) system

MOBM

1980 Cost of 3-D post time depth 

migration (PTDM) estimated at $8 

million for 50 square miles

1981 First offshore horizontal well (Rospo 

Mare field, offshore Italy)

1983 Horizontal wells drilled from vertical 

shaft (Kern River, CA)

1984 First steerable drilling system

New resistivity measurement 

devices

1985 3-D vertical seismic profiling 

developed
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 20 of 

33

Year

Drilling Technology Drilling Fluid SCE

1986 Metal sealed-bearing roller cone 

bits

Neutron porosity measurement 

capability added to MWD

1987 First logging while drilling (LWD) tool

1988 Extended-reach drilling exceeds 60-

degree radius

First horizontal well drilled from 

semisubmersible drill rig

1989 Only 5% of Gulf of Mexico wells 

based on 3-D seismic data

1990 Horizontal well achieves 14,585 

linear feet

1991 15,000-foot horizontal well drilled 

with directionally controlled coiled 

tubing

1992 Slimhole horizontal well (3 3⁄8”) 

drilled 801 feet

1993 3-D surveys worldwide cost $1 

million for 50 square miles

First SBM in GOM

MWD tools advance—smaller, 

broader temperature range, 

pressure detection, geosteering

1994 Digital image processing of 3-D

1995 3-D seismic used for 75% of U.S. 

onshore surveys

4-D seismic emerges

1996 80% of Gulf of Mexico wells based 

on 3-D seismic data

4-D seismic characterization 

methodology applied to previously 

recorded seismic surveys
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 21 of 

33

Year

Drilling Technology Drilling Fluid SCE

1997 Extended-reach drilling achieves 

26,450 feet horizontal displacement 

in South China Sea

1998 Magnetic resonance imaging begins 

on MWD

2000 3-D PTDM cost reduced to $90,000 

for 50 square miles by the year 2000

2005 Deepwater GOM

2010 Deepwater GOM

A major focus of the NPDES permitting system was removal of conventional pollutants such as 

oil and grease. Therefore, the early permitting efforts in the 1970s for drilling fluids and cuttings 

discharges, the US EPA restricted and eventually prohibited the discharge of OBM and cuttings. 

Since the evaluation of WBM discharges did not result in a water quality or sediment quality 

issue the focus of regulatory developments shifted to technology standards which are pursued to 

minimize conventional, non conventional and toxic pollutants using a technology standard. 

Through a process of regional EPA offshore permits and eventually the effluent limitation 

guidelines, the US EPA issued effluent limitation guidelines for produced water, drilling fluids, 

drill cuttings and various other offshore discharges. The resulting limits set the technology 

criteria and structure for environmental performance for offshore drilling and production. While 

the evaluation of fluids and development of testing took many years and was not a surprise, 

when the technology-based toxicity limit of 30,000 ppm (of suspended-phase particulates as 

toxicants) went into effect (EPA, 1996), it was a steep learning curve for operators to adjust to a 

new limit on the drilling fluid additives they could use. Just like a mechanic who has had several 

tools taken from his tool box, adjustments were made to react to the technology-based limits that 

sometimes resulted in increased cost or alternative drilling practices. For example, traditional 

use of mineral oil as a lubricant and use of potassium chloride (KCl) for shale inhibition were 

stopped because they did not meet the technology-based limits. In their place, operators did 

more short trips and back reaming to control reactive shales and prevent stuck pipe. Since the 

mid 1980s drilling-fluid companies have continued to market wave after wave of specialized 

chemistry to address shale hydration and lubricity. The first systems for hauling drill cuttings 

and drilling mud were developed during that time, since not all drilling fluids and cuttings could 

be discharged (OBM and some WBM that failed the toxicity limit). Those systems typically 

used cuttings boxes which were transferred by barge or truck to shore for treatment and disposal. 

The cycle of OBM and WBM technology was broken in the early 1990s with the introduction of 

SBMs. Both the EPA and industry were challenged to find ways to appropriately use and 

regulate SBM technology. Eventually, a special set of effluent limitations were developed for 

SBMs and cuttings dryers were used to remove residual SBM from the cuttings. 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 22 of 

33

During the 1970s on the other side of the Atlantic Ocean, the operators in the North Sea faced 

significant operational and drilling challenges. In order to address those challenges OBM was 

used and the drill cuttings were discharged. In the 1970s, those OBMs used diesel, however, as 

early environmental investigations revealed that diesel muds were toxic to marine life, lowertoxicity mineral oils were introduced. Continuing environmental investigations revealed that 

while mineral oils were not toxic, they tended to persist for many years due to their branched 

paraffin structure. Concerns about sediment quality resulted in SBMs, and many other advanced 

technologies to transport and treat OBM and SBM cuttings from 1969 though the current times.

During the same time frame of the 1970s though the current age, research into onshore impacts 

also developed along the lines of scientific research and regulatory development. As with 

offshore discharges, initial focus on traditional drilling fluid components focused on potential 

toxins and environmental impacts. As with offshore concerns the basic ingredients of barite and 

bentonite were found to be non-toxic and have low environmental impacts. Specialty additives 

such as XC-PolymerTM (based on xanthum gum) and starches that are commonly used in food 

products also were determined to be low environmental hazards, Consequently, the focus on 

shore became the use of inhibitive chloride salts (CaCl2, NaCl and KCl) which were found to 

inhibit plant growth and also cause toxicity in freshwater supplies. Other specialty additives 

such as sodium bi-chromate used as an additive in high temperature wells were determined to be 

environmental hazards. Over a short period of time, the compounds that were identified as toxic 

environmental hazards in WBMs were removed from drilling-fluid products and replaced with 

less toxic components that fulfilled the same functional purpose. States had traditionally 

regulated oil and gas operations with organizations such as the Texas Railroad Commission and 

the Oklahoma Corporation Commission. As the science-based evaluations did not reveal the 

need for regulation under the federal Resource Conservation and Recovery Act (RCRA), states 

continued to evolve their rules for E&P waste to address the remaining issues associated with 

onsite and offsite waste management. 

During Stage 3 of development, some advanced technologies have moved well beyond 

traditional waste management techniques. Those advanced technologies are further discussed in 

the next section to demonstrate how they evolved within the triad of environmental, operational 

and economic drivers.

VARIATIONS BASED ON RESOURCE TYPE AND LOCATION

Thermal treatment evolved as a treatment technology for OBMs. As previously discussed, 

OBMs were developed as a drilling-fluid technology because of the operational need to drill 

difficult formations at high temperatures. Thermal treatment is a common industrial process 

used to process slurries and sludge that share physical and chemical characteristics of OBM

cuttings. During the evaluation of offshore drilling discharges, OBM cuttings were identified as 

an environmental discharge issue in the offshore environment. Thermal recovery of base fluids 

and the ability to treat a wide range of feedstocks resulted in several designs for thermal 

treatment. One such treatment approach was provided a demonstration permit in the Gulf of 

Mexico to treat mineral oil-based mud cuttings on-site and then discharge them if they met a 1% 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 23 of 

33

residual oil content (ROC) limit. That technology demonstration did not meet the operational or 

cost targets and other onshore thermal-unit designs could not compete with the economics of 

commercial disposal that evolved in the Gulf of Mexico region. Thermal units achieved new life 

when the regulatory objective of a 1% ROC limit for all non-aqueous fluids was adopted in the 

North Sea in the year 2000. Several commercial onshore thermal units combined with landfill 

disposal of the residual solids operated successfully because they met the regulatory operational 

and economic needs of the region. Among the thermal units in use, the hammer mill technology 

became a standout and has continued to evolve into the current effort to place hammer mill 

thermal units on offshore rigs to meet the 1% discharge limits for non-aqueous fluids. The high 

processing rate, small footprint and recovery of base fluids are all positive attributes for thermal 

recovery technology. Because thermal processing is a treatment technology and not a disposal 

technology it must be combined with some type of onsite or offsite disposal of the residual 

solids, recovered water and oil. Thermal treatments face a range of technical, economic and 

environmental challenges. One reoccurring issue is the combination of high temperatures and 

flammable hydrocarbons, a safety issue that sometimes has resulted in thermal units being placed 

away from drilling operations. More importantly, thermal units are typically not very mobile and 

therefore must be set up in a centralized facility and then have the cuttings hauled to the 

treatment location. That lack of mobility means that, on top of treatment costs, transportation 

costs and disposal of residuals must also beat the cost curve for other waste-management 

options.

Injection technology evolved as a treatment technology to address issues in three areas. First, on 

the North Slope of Alaska, injection was introduced to address a lack of surface area for 

treatment and disposal. Use of conventional waste-management approaches like onsite disposal 

would have resulted in conversion of tundra to disposal site. In that situation, operatorcontrolled injection wells provided a successful waste-disposal technology with minimal 

footprint. Injection continued to see limited use in specialized areas until the market opportunity 

in the North Sea which resulted from the 1% discharge limit applied to OBMs. Injection 

technology practiced in the offshore environment allowed drilling and reinjection to occur 

without removing the drill mud and cuttings from the point of origin. The use of injection 

technology has a strong technical advantage because the application of injection technology is 

related to a strong understanding of underground formations. Clearly the exploration and 

production industry has a good pool of knowledge, experience and confidence to address 

complex problems associated with underground formations. In the case of fracturing formations 

and re-injection of the cuttings, specialized computer models help design planning and operation 

of injection sites to prevent unexpected results. Like all forms of waste management, injection 

technology has limitations. The most common limitation for injection technology can be lack of 

appropriate formations to receive the waste injections. Other common problems are limited 

injection rates which result in the need to store drilling cuttings and mud during periods of rapid 

generation of waste. Another significant challenge for injection technology is the difficulty of 

addressing technical failures of the technology. In the case of thermal units, if a batch of cuttings 

does not meet discharge limits the residual solids can be recovered and reprocessed. In the case 

of injection technology, a technical failure can result in waste being released into inappropriate 

formations and or creating breaches to the surface. In the failure-mode cases, the drilling waste 

cannot be recovered and if the accidental release is into a drinking water aquifer it is difficult to 

remove the contaminants from the affected formation. Consequently, continuing evolution of
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 24 of 

33

the technology has focused on the science of predicting and confirming that the injected waste is 

going where it is intended to go and staying where it is intended to stay. Injection technology 

has a strong presence in some areas as a commercial waste-disposal technology. In the Gulf of 

Mexico, injection of oilfield waste into salt domes is the current predominant waste management 

technique and is enjoying bother commercial and technical success. Other regions that do not 

have an established disposal infrastructure or have footprint constraints have successfully 

employed injection technology as a viable waste-management strategy (Veil and Dusseault, 

2003; Puder et al., 2003; Geehan et al., 2006). 

The third evolving technology is a combination of bioremediation, land application, and 

beneficial re-use as a soil enhancer. As with the other two technologies discussed, the process of 

biodegradation as a treatment technology developed initially to treat the oil in OBM cuttings. 

Land treatment has been a long-time practice to manage the low hazard aspects of WBMs. 

While the traditional focus of these techniques has been on appropriate management of the 

wastes, there was a recognition that some benefits to soil from the application of residual 

drilling-fluid components, Building on the positive aspects of this technique, both water-based 

and synthetic-based drilling fluids have developed product lines specifically targeted to provide 

beneficial residual properties to drilling fluids and cuttings so that instead of being approached as 

waste, the cuttings are approached as a byproduct with beneficial applications, In one specific 

region, cuttings were combined with other byproducts in a vermiculture application to generate a 

beneficial byproduct that could be used as a soil enhancer. In the case of bioremediation and 

beneficial reuse as a soil amendment, technical limitations frequently involve climate and land 

use. In cases where appropriate land areas or soil applications are available this is a viable 

technology. In areas such as the Alaska North Slope where the focus is on minimizing footprint,

and the climate conditions also are not favorable for bioremediation, then other waste-treatment 

technologies have a technical and economic advantage (Growcock et al., 2002; Norman et al., 

2002). 

The fourth and final technology evolution for waste management is the use of stabilization and 

beneficial reuse of drilling waste as a construction aggregate. This approach has its origins in the 

stabilization of salts, heavy metals and hydrocarbons found in oil based mud cuttings. Rather 

than attempting to remove the unwanted constituents in OBM and cuttings, this technology 

focused on chemical stabilization and fixation to prevent leaching of contaminants into the 

environment. As both drilling fluids and treatment technology have evolved, the use of 

stabilization techniques can combine low levels of contaminants with other byproducts to 

generate construction aggregate that meets target properties. One of the key technical and 

economic challenges of this technology is generating sufficient quantities of construction 

aggregate to meet a sustained building program. Therefore, the current applications have been 

focused on the large centralized treatment facilities and used along with other available materials 

to create a viable construction aggregate.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 25 of 

33

ENVIRONMENTAL BENEFITS

In practice, the selection of a waste-management approach is influence by a combination of 

factors, including what is technologically possible as well as what is required or permitted by 

regulations. Among all factors, possible benefits to environmental quality are high-priority 

considerations although the exact benefits will vary with the waste-management approach that 

might be dictated by other limitations. If all other factors were equal in all circumstances, and 

environmental benefits were the main selection criteria, the comparison and contrast of different 

technologies would be as summarized in Table 5.

Table 5. Benefits Offered by Different Waste-Management Methods.

Technology Air Discharge 

Benefits Water Discharge Benefits Land Disposal Discharge Benefits

Waste Minimization

Product 

substitution to 

remove 

constituents of 

concern 

Removal of 

contaminants

Removal of contaminants Removal of contaminants

Inhibitive waterbased drilling fluids 

improves drilling 

efficiency and 

lowers drilling time.

Replacement of soluble salts 

with polymers and organicbased inhibition chemistry 

reduces pollutant loading on 

water sources

Replacement of heavy metals and 

diesel with other specialty products 

reduce pollutant loadings.

New drilling fluid 

products that 

remove a 

recognized 

environmental 

hazard such as 

heavy metals, salt 

or oil

Removal of environmental 

hazard from the product 

removes or deduces the 

concentration of the hazard in 

the drilling fluid waste.

Some constituents that have 

environmental hazards are 

extremely effective products that 

are required for efficient drilling.

New drilling fluid 

systems targeting 

drilling fluid 

products that act 

together to achieve 

better performance

Can increase drilling 

efficiency, reduce cost and 

improve environmental 

performance

Can also reduce all pollution loads 

that require land based disposal.

Improve 

mechanical 

solid control 

efficiency

Improved removal 

efficient increases 

penetration rates 

and reduces air 

discharges 

associated with 

motors.

Advanced technology 

promotes high removal 

efficiency and lower loading 

on water discharges offshore

Advanced performance is 

ineffective in situations where 

cutting size degrades in the 

wellbore and reduced discharges 

to land.

Hydrocyclones, 

mud cleaners and 

other secondary 

solids control 

equipment reduce 

pollutant loads and 

shorten drilling time

Reduced pollutant loads 

reduce potential impact to 

water

Reduced pollutant loads reduce 

land disposal of residuals. 

Chemically 

enhanced solids 

Recovers water from drilling 

fluid contaminated with fine 

By minimizing dilution educed 

solids loading to land discharges.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 26 of 

33

Technology Air Discharge 

Benefits Water Discharge Benefits Land Disposal Discharge Benefits

separation 

equipment

solids

Closed loop 

secondary 

treatment 

systems for 

drilling fluids

Drilling 

Practices

Mud tanks and 

reserve pit settling 

basins

Simple and low cost 

alternatives

Inefficient and frequently 

generates large volumes of waste.

Extended reach, 

horizontal drilling 

multiple laterals

Reduced volume of cuttings 

and other waste by increasing 

efficiency

May be impractical in some 

locations and can increase cost.

Closer spacing of 

successive drill 

strings, slimhole 

drilling, coiled tube 

drilling

Smaller wellbore produces 

less waste.

Reduces production volumes in 

some cases.

Use of air or other 

gases to as the 

drilling fluid

Removes need for drilling fluid 

and reserve pit

Not applicable in many areas.

Directional 

drilling

Allows for lower 

footprint and 

reduced number of 

wells and 

associated air 

discharges

Reduces number of wells and 

associated water discharges

Reduces number of wells and 

associated land discharges

Reuse and Recycling

Thermal 

treatment 

Greater drilling 

efficiency with the 

use of OBM and 

minimization of air 

discharged from 

treatment with 

recover of oil 

Lower concentrations of 

contaminants in residual 

solids discharged offshore

Lower loading rates for land 

disposal 

Bioremediation 

and beneficial 

reuse in land 

application or 

wetlands 

application

Greater efficiency 

of drilling reduces 

air pollutant 

loading, low energy 

treatment 

requirements 

reduce air pollutant 

loadings

Reduced pollutant loading to 

water discharges

Reduced pollutant loading to land. 

Daily cover for land 

fills

Stabilized cuttings are an 

effective cover material

Other types of 

construction 

material

Can be used to develop drill 

pads

Stabilization 

and use as a 

construction 

material

Greater efficiency 

of drilling reduces 

air pollutant

loading, low energy 

treatment 

requirements 

reduce air pollutant 

loadings

Reduced pollutant loading to 

water discharges

Reduced pollutant loading to land. 

Water Disposal
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 27 of 

33

Technology Air Discharge 

Benefits Water Discharge Benefits Land Disposal Discharge Benefits

Onsite burial 

(Pits, Landfils)

Reduced emissions 

related to hauling 

cuttings.

Protection of water supplies 

with appropriate design and 

operation of pits

Focus on pit constituents instead 

of pits themselves protects land 

use.

Discharge to 

Ocean

Reduced emissions 

related to hauling 

cuttings.

Protection of water supplies 

with focus on mud 

constituents

Reduced land disposal with onsite 

offshore disposal.

Commercial 

disposal 

facilities

Reduced treatment 

emissions

Protection of water supplies in 

a controlled treatment facility

Protection of land resources in a 

controlled treatment facility

Slurry Injection Reduced emissions 

related to hauling 

cuttings

Protection of water supplies 

with appropriate design and 

operation of slurry injection

Reduction of land use with 

appropriate design and operation 

of slurry injection

Bioremediation/ 

land application

Reduced emissions 

related to hauling 

cuttings.

Protection of water supplies 

with focus on beneficial reuse

Beneficial reuse increases land 

value.

Disposal in salt 

Cavern

Reduced air 

emissions related 

to treatment of 

cuttings

Protection of water supplies in 

a controlled treatment facility

Protection of land resources in a 

controlled treatment facility

OUTLOOK FOR DRILLING WASTE MANAGEMENT

A. Innovation and Future Use

Innovation has been a continuous presence in the application of technology in the E&P industry. 

While some become frustrated in the slow pace of the introduction of new technology, field 

experience has demonstrated that many technologies that have been successfully applied in other 

industries struggle to perform in the harsh and often unforgiving conditions of the oilfield. 

Unlike conventional industries that operate in mature, populated locations under controllable

conditions, oilfield technology must perform in remote and often extreme conditions. 

Consequently, new technology must be adapted to work in E&P applications and supported at 

the field level with experienced personnel.

Innovation is in response to challenges and the environmental, operational and economic 

challenges will continue to change as they have for the past 100 years. So far the discussion of 

technology has focused on treatment of contaminants. Equally important to addressing 

contaminants in the feed streams and by products are some of the critical innovations have 

occurred in the area of environmental assessments, including development of new tools to 

monitor and predict environmental performance. In the future, environmental performance 

evaluations will respond to new performance indicators on individual discharges and receiving 

environments and will evolve to life-cycle assessments, biodiversity protection, and multimedia 

assessments of environmental performance of operational and waste management technologies. 
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 28 of 

33

While the evaluation parameters will continue to evolve, the basic triad of issues will continue to 

balance environmental control technologies with operational and economic considerations of 

E&P operations.

B. Barriers and Opportunities

The opportunities and the barriers for new technology are the same three elements discussed for 

all of the past, present and future treatment technologies.

The first barrier is operational. Any pollution prevention, recycling or disposal technology must

perform to meet drilling operational or product requirements. Not every well is successfully 

drilled, and not every waste-management technique is successfully applied. In many cases, it 

takes several attempts to identify and address the operational needs of the particular region. The 

application of technology is particularly difficult in the E&P industry due to environmental 

conditions and remote locations.

The second barrier is environmental. While economic and operational barriers are usually 

clearly understood, environmental challenges are frequently a mix of scientific, regulatory and 

legal requirements. In some cases regulations have exclusively focused on regulated existing 

technology with little or no room for addressing innovative technologies. In some cases the 

technologies listed above have been prohibited due to past issues but with no allowance for 

technology improvements. Consequently improvement in the development of regulations is an 

overall opportunity for future improvements. Technology associated with evaluation and 

protection of the environment is also a barrier to development appropriate limitations for 

technology and is an opportunity for future improvements.

Finally, economic barriers are a major impediment for application of new technology. There are 

three aspects of economic performance. One evaluation results in the ability of a technology to 

address a certain contaminants in a waste stream, A larger economic evaluation looks at the 

overall economic viability of an enterprise in the context of operational and environmental 

requirements, Still in a large economic view, energy and environmental policy and the resulting 

economic conditions can drive the need for oil and natural gas in the context of other energy 

sources with higher and lower end-use emissions.

C. Long-Term Vision

As described in the preceding sections, management of waste from oil and gas production is 

accomplished through many different technologies and practices. It is challenging to envision 

the future of water management with so many different operational and environmental settings. 

Future waste management technologies are likely to focus on:

• Reduced treatment costs

• Reduced air emissions, including CO2

• Minimizing transportation
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 29 of 

33

• Minimizing energy inputs

• Capturing secondary value from the waste (extraction of minerals, power, or other 

factors)
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 30 of 

33

FINDINGS

Waste management technology is a critical element of successful drilling and production 

operations. Proper application of waste management principles is required for both efficient 

drilling operations and environmental protection. 

During drilling the largest potential waste stream is used drilling fluids and cuttings. The 

operational source of the drilling fluid and cuttings waste is the cuttings that are produced while 

drilling the well. 

Environmental regulatory considerations play a significant role in both the selection of drilling 

fluids and the overall economics of drilling a well. The specific regulatory requirements of an 

area often dictate the technologies that can be used and what, if any, material can be discharged 

into the environment. This, in turn, influences what and how wells can be drilled.

Many different technology options are available that can be employed at specific locations. 

Selection of a management option for waste management at a particular site varies based on: 

• The nature of the technical requirements of the drilling operation.

• The economics of drilling the well and managing the associated byproducts.

• The environmental requirements for a receiving environment and regulatory structure 

perspective.

Drilling waste-management technologies and strategies can be organized into a three-tiered 

water-management or pollution-prevention hierarchy (i.e., minimization, recycle/reuse, and 

disposal).

• Tier 1 – Minimization: The generation of waste is minimized within the processes for 

drilling a well. This approach is mutually beneficial across all three objectives of 

minimizing the cost of drilling the well, meeting the technical of the drilling operation 

and minimizing the impacts on the receiving environment. When feasible, inhibitive 

drilling fluids and efficient mechanical solids-control equipment can often save money 

for operators and results in greater protection of the environment.

• Tier 2 – Recycle/Reuse: For the drilling fluid and cuttings that cannot be managed 

through water minimization approaches, operators can plan for reuse or recycling of 

drilling byproducts. The most common ways to reuse drilling fluids is to re-deploy them 

at another drilling location or at least to recover the most valuable constituents of the 

drilling fluids from one location and move them to another drilling location. Substantial 

efforts are ongoing to develop economic methods to treat drilling fluids and drill cuttings 

so that they can be beneficially reused in oilfield and non-oilfield applications.

• Tier 3 –Disposal: When drilling waste cannot be managed through minimization, reuse, 

or recycle, operators must dispose of it.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 31 of 

33

Four main lines of technology have been developed to address drilling waste management which 

is centered on handling leftover drilling fluids or “muds” that can include water, oil and certain 

chemical additives:

• Thermal treatment uses heat to separate more objectionable components from less 

objectionable components based on differences in volatility. It is a common process 

applied to oil-based mud and cuttings where centralized processing is feasible and 

disposal options are available for the objectionable residuals. 

• Injection technology sends treated or untreated waste streams underground into geologic 

formations that can accept and safely isolate the waste. If geology and regulations 

permit, injection can serve to substantially simplify waste management while also 

reducing the surface footprint.

• High-order beneficial reuse on land comprises a combination of bioremediation and redeployment of treated wastes as soil amendments. It is most readily applied to waterbased muds although variations have been developed for some synthetic-based muds. 

• Lower-order beneficial includes re-deployment as construction aggregates. The 

treatment criteria for aggregate use can focus more on stabilization rather than complete 

remediation so that the stabilized waste is rendered environmentally inert.

Use of any given waste-management approach will continue to be decided by the interplay of 

economic, technical and operational barriers:

• Economic barriers for all waste management technologies are a combination of the cost 

of drilling and that value of the production. If the value of the production from a region 

is high then the economic stress on waste management techniques is reduced. 

• Technical barriers are relative to the type of waste management technology employed. 

Two areas that continue to advance with combined environmental and waste management 

benefits are drilling fluids and solids-control equipment. 

• Operational barriers continue to evolve as new areas of drilling challenges must address

downhole geological conditions and the difficulty of adapting technologies for the rigors 

of oilfield applications. 

Future waste-management technologies and practices most likely will find growing attention on 

biodiversity protection; changing energy policy with increasing focus on greenhouse gas 

emissions; progressively more difficult drilling environments such as offshore deepwater, Arctic 

conditions and extended-reach wells; and reduced landfill space available for waste disposal with 

implied greater reliance on beneficial reuse options.
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 32 of 

33

REFERENCES

ANL (2011). Drilling Waste Management Information System. Argonne National Laboratory, 

US Department of Energy. http://web.ead.anl.gov/dwm/techdesc/commercial/index.cfm

API (2000). Overview of Exploration and Production Waste Volumes and Waste Management 

Practices in the United States. Based on API Survey of Onshore and Coastal Exploration 

and Production Operations for 1995 and API Survey of Natural Gas Processing Plants for 

1995. Prepared by ICF Consulting for the American Petroleum Institute, May 2000, 112 

p. plus tables. http://www.api.org/aboutoilgas/sectors/explore/waste-management.cfm

EPA (1996). 40 CFR Part 435. Oil and Gas Extraction Point Source Category; Final Effluent 

Limitations Guidelines and Standards for the Coastal Subcategory; Final Rule. US 

Environmental Protection Agency. Federal Register, 61 (242), December 16, 1996, p. 

66086-66130. http://www.epa.gov/region6/6en/w/offshore/effluentguidelines-dec-16-

1996.pdf

EPA (1999). Development document for proposed effluent limitations guidelines and standards 

for synthetic-based drilling fluids and other non-aqueous drilling fluids in the oil and gas 

extraction point source category (EPA-821-B-98-021). US Environmental Protection 

Agency, Washington DC, February 1999, 282 p. 

http://cfpub.epa.gov/ols/catalog/catalog_display.cfm?&FIELD1=SUBJECT&INPUT1=C

hemical%20effluents&TYPE1=EXACT&item_count=37

ESRF (2004). Drilling Waste Management Recommended Best Practices. Prepared by Ellis & 

Associates Inc. for Environmental Studies Research Funds, Ottawa, Ontario, Canada, 

March 2004, 51 p. http://www.esrfunds.org/pdf/152.pdf

Geehan T., Gilmour A. and Guo Q. (2006). The cutting edge in drilling-waste management. 

Oilfield Review, 18(4), Winter 2006/2007, p. 54-67. 

http://www.slb.com/~/media/Files/resources/oilfield_review/ors06/win06/p54_67.ashx

Growcock F. B., Curtis G. W., Hoxha B., Brooks W. S. and Candler J. E. (2002). Designing 

Invert Drilling Fluids to Yield Environmentally Friendly Drilled Cuttings. Paper No. 

74474-MS, IADC/SPE Drilling Conference, Dallas, Texas, February 26-28, 2002, 12 p. 

http://www.onepetro.org/mslib/servlet/onepetropreview?id=00074474&soc=SPE

Neff J. M., McKelvie S. and Ayers R. C. Jr. (2000). Environmental Impacts of Synthetic Based 

Drilling Fluids. OCS Study MMS 2000-064. Minerals Management Service, US 

Department of the Interior, August 2000, 132 p. 

http://www.gomr.boemre.gov/PI/PDFImages/ESPIS/3/3175.pdf
Working Document of the NPC North American Resource Development Study Made Available September 15, 2011

Waste Management Page 33 of 

33

Norman M., Ross S., McEwen G. and Getliff J. (2002). Minimizing environmental impacts and 

maximizing hole stability– the significance of drilling with synthetic fluids in New 

Zealand. 2002 New Zealand Petroleum Conference Proceedings, February 24-27, 2002,

12 p. http://www.crownminerals.govt.nz/cms/pdf-library/petroleum-conferences-1/2002-

nz-petroleum-conference-proceedings/norman-216-kb-pdf

Puder M. G., Bryson B. and Veil J. A. (2003). Compendium of Regulatory Requirements 

Governing Underground Injection of Drilling Wastes. Argonne National Laboratory, US 

Department of Energy, February 2003, 206 p. http://www.evs.anl.gov/pub/doc/regcompendium.pdf

Veil J. A. and Dusseault M. B. (2003). Evaluation of Slurry Injection Technology for 

Management of Drilling Wastes. Argonne National Laboratory, US Department of 

Energy, February 2003, 110 p. http://www.evs.anl.gov/pub/doc/si-tech-report-1584.pdf

Wakim (1987). Wakim, P.G., "API 1985 Production Waste Survey, Statistical Analysis and 

Survey Results," American Petroleum Institute, Washington, DC, October 1987.