Oil & Gas industry Waste

Management

Prof. Dr. Mamdouh F. Abdel-Sabour Environmental Consultant International Innovative Environmental Solution Center (IIESC)

Introduction

A major challenge throughout the O&G

sector is that many waste streams can

become contaminated by oily or hazardous

fluids, and radioactivity requiring careful

handling, treatment and disposal.

Generated wastes at terminals may include

tank bottom sludge; this must be periodically

removed to maintain product quality or tank

storage capacity; as well as spill cleanup

materials and soils contaminated with oil.

Typically, sludge is composed of water,

residual product, and various solids including

sand, scale, and rust. Tank sludge and spill

cleanup materials should be dealt via re-

processing for product recovery or as a

waste at a licensed facility handling this kind

of material in an environmentally sound

manner.

Dealing with municipal solid-like waste,

and commercial and industrial waste in a

sustainable way presents significant

difficulties especially in the confined

working environments offshore.

To identify the challenges facing

the oil industry in achieving

sustainable management of all

wastes from inshore /offshore

production facilities, and

To compare and contrast the

most important factors that

affects waste management in

developed oil areas with those in

less developed, emerging oil

areas.

objectives

Waste Management

1 – Reduction: important in

manufacturing. Purchasing

products that includes these

features supports source

reduction. When a method is

chosen to reduce waste, pilot

testing may be suitable for initial

evaluation. Source reduction can:

Save natural resources;

Reduce pollution;

Conserve energy;

Reduce the toxicity of the

waste; and

Save money for consumers

and businesses alike.

2- Reuse: Use materials or

products that are reusable, such

as chemical containers, waste oil

for road building, burning waste

oil, and energy recovery.

Waste Management

3- Recycling/ Recovery: Waste

into usable/ or energy derived

from waste material, such as

scrap metal recycling, recycling

drilling mud used in the drilling

debris, oil recovery and reservoir

sedimentation water exploration

and production manufacturing

processes.

4 - Treatment: Detoxification

degradation, detoxification and/

or neutralization of the

remaining processes including

biological methods, incineration,

thermal analysis, neutralization,

chemical methods, stabilization

methods, and physical filtration

using centrifugal force.

Energy recovery Waste-to-energy which is a proven technology used globally

to generate clean, renewable energy from the sustainable

management of municipal solid waste

Multiple feedstock capability: Capable of receiving,

handling, processing and disposing, different types of wastes

(e.g., MSW, IHW) concurrently.

Complete destruction of wastes: Plasma gasification

process is a NO BURN process hence, it does produce

residuals, i.e., fly & bottom ashes as typically found with

incinerators. Fly & bottom ashes are harmful, may contain

heavy metals and require secure landfilling. Since plasma

gasification does not produced ash, landfilling will no longer

be a requirement.

Maximum energy recovery from wastes: Plasma

gasification process is designed and engineered to ensure

efficient energy recovery from wastes.

Environmentally friendly: Operating at temperature range

of about 3,000oC in the Gasification Zone in an oxygen

starved environment, are realised in the plasma reactor

therefore, plasma gasification process presents no

opportunity for formation of hazardous flue gases, e.g.,

dioxin & furans, SOx and Nox.

Type of generated wastewater

Storm and Process Wastewater Treatment

1)Storm-water

Contaminated storm water quality and volumes may depend on site-specific considerations

including overall housekeeping and spill prevention practices, rainfall, and total runoff area.

Natural gas processing facilities should provide secondary containment where liquids are

handled, segregate contaminated and non-contaminated storm water, implement spill control

plans, and route storm water from process areas into the wastewater treatment unit.

2)Tank Bottom Water

Water that separates and settles to the tank bottom should be periodically drained from the

bottom of the tank, resulting in a liquid effluent of oily water. Rainwater infiltration,

condensation of moisture from tank vapor space, and water present in the product itself

prior to delivery may all contribute to the presence of water inside product storage tanks.

3)Industrial Process Wastewater

Process wastewater may contain dissolved hydrocarbons, oxygenated compounds, and

other contaminants which should be treated onsite wastewater treatment unit

wastewater

4)Process wastewaters include:

Chemical Wastewater

Chemical drain system collects wastewaters that require neutralization before discharge

via return header of seawater cooling. The pH of the effluent must be adjusted between

6 - 9 in the neutralization sump by batch addition of 30 % HCl or 50 % NaOH.

Oily Wastewater

Oily wastewater must be directed to a retention pond and air floatation package which is

used to reduce oil content below 15 mg/l. Sludge from these treatment units shall be

directed to and treated in the wastewater treatment facilities.

Sour Wastewater:

Sour water from the AGR unit periodically requires disposal with small quantities of sour

condensate from LP sour gas flare drum. These wastewaters are treated by stripping off

gas from the nitrogen rejection unit before discharge to the oil contaminated drain.

For every tonne of hydrocarbon produced in 2010 (including oil, condensates and

gas) 0.6 tonne of produced water were discharged to the marine environment and

1.0 tonne of produced water was re-injected into the ground (OGP, 2011).

Type of generated waste

4) Cooling water

Cooling water may require high rates of

water consumption, as well as the potential

release of high temperature water, residues

of biocides and other cooling system anti-

fouling agents.

5) Hydrostatic testing water

Hydrostatic testing of equipment and

pipelines involves pressure testing with

generally filtered raw water to verify their

integrity and possible leaks detection.

Chemical additives may be added. A hydro-

test water disposal plan should be prepared

considering location and rate of discharge,

chemical use, dispersion, environmental risk,

and required monitoring if the only feasible

alternative for disposal of hydro-test waters

into the sea or to surface water. Hydro-test

water disposal into shallow coastal waters

should be avoided.

7) Ballast water

Gas processing that has a port/terminal shall ensure that

ships with segregated ballasts are used for all products

transport. Facilities that will carry out the ballast water

sampling and analysis should coordinate with Port

Authorities. Ballast water shall be tested to the following

standards prior to discharge. Parameter Units Limit

pH - 6-9

Biochemical Oxygen Demand (BOD) mg/l 50

Chemical Oxygen Demand (COD) mg/l 250

Total suspended solids mg/l 35

Oil & grease mg/l 15

Visible oil & grease - None

Total Organic Carbon mg/l 100

Ammonia, as N mg/l 3

6) Sanitary wastewater

The sanitary drain system receives wastewater from all

process, utility, offsite, and off plot areas including services

expansion facilities. The wastewater should undergo

biological treatment units based on extended aeration and

activated sludge and should be channeled to MBR tertiary

treatment package for further polishing. The use of

detergents, surfactants, and dispersants shall be minimized

except as necessary to maintain a safe workplace.

Hazardous &Non-hazardous Waste

1.Non-hazardous Waste

Non-hazardous industrial wastes consist mainly of exhausted molecular sieves from the air separation unit as well as domestic wastes. Other non-hazardous wastes may include office and packaging wastes, construction rubble, and scrap metal.

2.Hazardous Waste In GTL facilities, hazardous wastes may include bio-sludge; used containers and oily rags; spent catalysts; spent oil, solvents, and filters (e.g., activated carbon filters and oily sludge from oil water separators); mineral spirits; used sweetening; spent amines for CO2 removal; and laboratory wastes.

Hazardous waste

Spent catalysts

Spent catalysts from GTL

production are generated

from scheduled

replacements in natural gas

desulphurization reactors,

reforming reactors and

furnaces, reactors for mild

hydro-cracking, and Fischer-

Tropsch synthesis reactors.

Spent catalysts may contain

iron, zinc, nickel, platinum,

palladium, cobalt, and

copper; depending on the

particular process.

Heavy Ends

Heavy ends or distillation residues

from the production of carbon

tetrachloride

Heavy ends from the purification

column in the production of epi-

chlorohydrin

Heavy ends from the fractionation

column in ethyl chloride

production

Heavy ends from the distillation of

ethylene dichloride in ethylene

dichloride production

Heavy ends from the distillation of

vinyl chloride in vinyl chloride

monomer

12

أماكن وجود المواد المشعة الطبيعية في صناعة النفط

نفط

NORM wastes generated from oil

and gas production. In gas processing

activities, NORM generally occurs as

radon gas in the natural gas stream.

Radon decays to Lead-210, then to

Bismuth-210, Polonium-210, and

finally to stable Lead-206. Radon

decay elements occur as a film on

the inner surface of inlet lines,

pumps, treating units, and valves

principally associated with ethane,

propylene, and propane processing

streams.

6.1 Management of Basic Waste Types

According to OSHA the average radium concentration in scale has been estimated to be 17.76 Bq/g (EPA, 2011). It can be much higher (as high as 14,800 Bq/g) or lower depending on regional geology. The average concentration of radium in sludge is estimated to be 2.775 Bq/g. This may vary considerably from site to site. Although the concentration of radiation is lower in sludge than in scales, sludge is more soluble and therefore more readily released to the environment. This result poses a higher risk of exposure.

Scales in pipes and vessels are the most common

NORMs in the petroleum industry. Scales on

equipment are low in volume. Scales are solid

minerals that precipitate from produced water

which has high salinity and contains sulfates

and/or carbonates plus calcium, barium and

strontium. Scale-forming material may also

precipitate on sand and sludge particles and debris

of scale may be mixed with sludge and sand inside

vessels. The most common scales consist of

barium sulfate (BaSO4), strontium sulfate (SrSO4)

or calcium carbonate (CaCO3). The relative

amounts of solid waste vary with the production

area due to the different geological characteristics

of the oil/gas reservoirs.

Management of Basic Waste Types

The most important scale formation

processes are mixing of incompatible

waters and temperature changes. When

scale precipitates from a large volume of

formation/produced water, radium is

concentrated within a small amount of

solid scale such that the radium

concentration in scale exceeds the

radium concentration in the

formation/produced water by several

orders of magnitude.

Approximately 100 tons of scales

per oil well are generated annually

in the United States.

Sludge is composed of dissolved solids

which precipitate from produced

water as its temperature and pressure

change.

Dried sludge, with low oil content,

looks and feels similar to soil. Like

contaminated scale, sludge contains

more Ra-226 than Ra-228.

Disposal petroleum pipes containing

sludge and scale as a technically

enhanced natural occurring radioactive

material (TENORM) leads to internal

and external radiation hazards and

then a significant radiation dose to the

workers.

Sustainable Waste Management Plan

Management plan must consider life

cycle sustainability.

Responsible persons, needed

resources and planned objectives shall

be set in such a way that the variety of

programs and facilities management

system is available.

Waste classification on physical,

chemical and its toxicity must be

identified.

Technical criteria and guidance

documents on oil and gas waste

management have been issued by API

and the Interstate Oil and Gas

Compact Commission (IOGCC)

(Green, 2008) to supplement efforts

to improve such management.

API and OGP provide the starting

point for any company that evaluates

its waste management plan, or

assessing environmental performance

of treatment facilities, both in

developed and less developed

countries (OGP, 2011, API, 2009, OGP,

2008,.

A classification system for waste

streams may be formed in accordance

with the health and environmental

hazards.

Waste Management may consider

practical measures, i.e., reduction of

source, recycle and reuse, recovery,

and final disposal of remaining waste.

These measures are as follows:

Loading / unloading activities should be conducted by properly trained personnel

according to pre-established formal procedures to prevent accidental releases and fire

/explosion hazards. Procedures should include all aspects of operation from arrival to

departure, including wheel blocking to avoid vehicle movement, verification of proper

hose connection and disconnection, connection of grounding systems, adherence to

no-smoking and no-naked light policies for visiting drivers;

For unloading / loading activities involving marine vessels and terminals, preparation

and implementation of spill prevention procedures for tanker loading and off-loading

according to applicable international standards and guidelines which specifically

address advance communications and planning with the receiving terminal;

Facilities should develop a spill prevention and control plan that addresses significant

scenarios and magnitudes of releases. The plan should be supported by the necessary

training and resources. Adequate spill response equipment should be conveniently

available to address the most likely types of spills. Spill cleanup materials should be

managed as discussed below;

Where appropriate, spill control and response plans should be developed in

coordination with the relevant local regulatory agencies;

Above Ground Storage Tanks (ASTs) should be protected from potential collisions by

vehicles, vandalism, located in a secure area, and other hazards. Additional guidance on

ASTs is presented in the General EHS Guidelines.

5. Pollution Prevention

Pollution prevention, including the removal, modification or reduction

operational measures that lead to pollution of land, air or water, such as; waste

prevention, handling, and treatment methods.

API (2001) estimated that in 1985 about 92 % of oil and gas wastes was injected

underground, 4% was discharged into waterways, and 2 % was managed in surface

impoundments.

These methods include:

1) Re-injection,

2) Incineration,

3) Down-hole

4) Oil-Water Separation Technology,

5) Compaction/ Shredding,

6) Waste to Energy,

7) Landfill,

8) Advanced Thermal Treatments (e.g. gasification, pyrolysis),

9) disposal in Salt Caverns,

10) Bio-remediation, and Evaporation pits.

6. CURRENT MANAGEMENT PRACTICES

The major method for waste

management in oil& gas sector

include:

surface impoundment;

land application and

landfilling;

waters source reduction and

recycling;

underground injection; and

discharge to surface.

5. Pollution Prevention

All non-hazardous solid waste from construction or operational

activities shall be managed at the industrial waste facility, once

this becomes operational and is within the terms of User

Agreement.

All offsite waste shipments shall utilize a manifest system for

tracking. Report the summary of all offsite waste shipments to

the environmental Authority each quarter.

All hazardous solid waste shall be safely stored in a contained

facility until such wastes can be treated to a non-hazardous state

or exported to an approved treatment facility as per Basel

Convention.

An inventory of all stored hazardous wastes shall be reported

to the Environment authority each quarter.

5. Pollution Prevention

Any waste material stored on site shall be done at an approved

hazardous Waste storage facility. The storage facility shall not

hold more than 3 months of inventory at any point of time. All

Hazardous waste shall be disposed-off locally or internationally

within 90 days.

Waste Lube oil shall be disposed-off at a facility approved by

environmental authority and reported on the quarterly EMP

report.

Total quantity of solid waste generated on a yearly basis (in

tonnes) shall be forwarded to the environmental authority with

the 4th quarter EMP report. This report shall have a breakdown

of solid waste by three major categories viz., Hazardous, Non-

Hazardous and Inert.

Surface Impoundments

According to EPA (1984), more than 125,000 oil and gas surface

impoundments existed in 1984. Based on EPA data from 1980s (GWA, 2005),

only 2.4 % of the surface impoundments used for oil and gas wastes had

synthetic liners, whereas another 27 % had a natural liner of unknown

composition quality.

Reserve pits are used to temporarily store drilling fluids for use in drilling

operations or waste disposal. Of all materials discharged to reserve pits, an

estimated 90 % are drilling fluids (mostly in the form of drilling muds and

completion fluids) and cuttings.

Adding solidifiers for solidification of pit contents is one potential alternative

(e.g., commercial cement, fly ash, or lime kiln dust) to help immobilize

pollutants and minimize leaching of toxic constituents. One problem in

solidification is after removal of the free liquid fraction of pit wastes, the

remaining pit contents still contains about 30 percent water. In addition, the

use of cement kiln dust, and possibly other solidifiers, increases the volume of

solid waste to be managed (Karami et. al., 2013).

Landfilling and Land Application

The petroleum products from the soil during land farming are largely removed

through biodegradation, volatilization and adsorption (Hejazi et al. 2003). Lighter

petroleum products like gasoline may be removed by volatilization during land farm

aeration process and to a lesser extent, degraded by microbial respiration (EPA,

1994). The mid-range petroleum products like diesel fuel and kerosene contain lower

percentage of lighter constituents than does gasoline. Bio-degradation is more

significant than volatilization for these petroleum products. The dominant

mechanisms that break down heavier or non-volatile petroleum products like heating

oil and lubricating oils are biodegradation. Adsorption also plays an important role in

the dissipation of petroleum products from the soil.

The efficiency of removing petroleum compounds from the soil can be impacted by

the soil moisture. The moisture level in most land farms is kept between 30 and 80%

field capacity (Pope & Mathews 1993; Malina et al. 2002).

Adsorbents like clay and organic matter, which are site-specific can decrease the

bioavailability of toxic compounds and therefore result in a lower risk for higher

organisms (reduction in toxicity) and lower biodegradation efficiency as

contaminants are tightly bound to the soil matrix (Guerin & Boyd 1992). It was

reported that during the last two decades, (Verstraete & Top 1999; Holden & Firestone

1997), that it is possible for the land-farm can treat petroleum products in an

environmentally safe manner.

Deep-Well injection

Injection wells used for disposal are often older wells that

require more maintenance (EPA regulations require

periodic testing of the mechanical integrity of the injection

wells).

For final disposal purposes, about 90 % of produced waters

from onshore oil and gas operations are disposed of in

more than 166,000 underground injection wells (Karami et.

al., 2013).

Produced waters are injected (via gravity flow or pumps)

into saltwater formations, the original formation, or older

(depleted) formations when used for disposal.

5. Pollution Prevention

Class II injection well is equipped with constant

pressure monitoring, corrosion inhibitors, leak

detection, and automatic shutoff.

Many US-States restrict the types of wastes that

can be stored in pits at Class II well sites, and

require lining of these facilities (with either

synthetic or clay liners, depending on site-specific

conditions) and, where groundwater is present,

groundwater monitoring systems is required

(Voutchkov,2011).

In addition, pumps can be built with features that

minimize releases, and tanks can be used as an

alternative to liners.

These practices generally afford more protection

than systems that allow disposal of tank bottoms,

produced waters, and other wastes in unlined pits

or on the ground (Walker et al 2007).

Discharges to Surface Waters

Discharges to surface waters are permitted under the environmental limit:

1) Into coastal or tidally influenced waters;

2) For produced waters from stripper oil wells to surface streams; and

3) For agricultural and wildlife beneficial use.

Treatment often occurs before discharge to control pH and to minimize oil

and grease, total dissolved solids, sulfates, and other pollutants. Radiation and

benzene or other organic chemicals presence.

To minimize generation of oil contaminated storm-water runoff primarily

includes the following measures:

Application of effective spill prevention and control;

Secondary containment procedures implementation to avoid

accidental or intentional releases of contaminated containment fluids;

Installation of stormwater channels and collection ponds with

subsequent treatment through oil / water separators. Oil / water separators

should be properly selected, designed, operated, and maintained.

Discharges to Surface Waters

The mixing of hazardous wastes with non-hazardous or exempt oil and gas wastes is

not recommended by EPA to some types of “recycling” (EPA, 1984). According to an

analysis by Amoco Corp., the method of basic waste minimization can potentially

reduce the volume of drilling fluids, including cuttings, by more than 60 % (API,1996).

EPA estimated that “closed-loop systems” can reduce the volume of drilling fluids by as

much as 90 %. (API, 1994). Closed-loop systems use mechanical solids control

equipment (e.g., screen shakers, hydroclones, centrifuges) and collection equipment

(e.g., vacuum trucks, shale barges) in minimizing the drilling waste muds and cuttings

that require disposal and maximizing the volume of drilling fluid returned to the drilling

mud system.

EPA and API indicate that fluids in some reserve pits contain lead, chromium, and

penta-chlorophenol at hazardous levels; and oil-based fluids may contain benzene. It is

possible to reduce the toxicity of drilling fluids. These components can potentially be

reduced or eliminated.

Training on waste management for contracted service providers should not be left to

installation managers on production platforms and vessels. Offshore waste procedures

often different to those onshore must be instilled beforehand by the service provider.

Full segregation at source should be nurtured at all production facilities.

Techniques for treating industrial process

for separation of oils and floatable solids; flow and load equalization; filtration for

separation of filterable solids; sedimentation for suspended solids reduction using

clarifiers; biological treatment, typically aerobic treatment, for reduction of soluble

organic matter (BOD); chlorination of effluent when disinfection is required;

chemical or biological nutrient removal for reduction in nitrogen and phosphorus;

and dewatering and disposal of residuals in designated hazardous waste landfills.

Typical wastewater treatment steps include:

Grease traps,

Skimmers,

Dissolved air floatation, or

Oil / water separators