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1. HEALTH SAFETY AND ENVIRONMENT
JNTUK
IV YEARB.TECHPETROLEUMENGINEERING
I-SEMISTER
UNIT-I

2. HEALTH SAFETY AND ENVIRONMENT
UNIT-I (Chapter 1&2)
• Introduction to environmental control in the petroleum
industry: Overview of environmental issues- A new attitude.
(Pages 1to 16)
• Drilling and production operations: Drilling- Production- Air
emissions. (17 to 68)

3. Introduction to environmental control in the
petroleum industry
 Exploration and production activities of petroleum industry provides
essential petroleum products.
 The activities of finding and producing petroleum can impact the
environment and the greatest impact arises from the release of wastes
into the environment in concentrations beyond nature accepts.
 The wastes include HCs solids contaminated with HCs, water
contaminated with a variety of DS, SS and variety of chemicals.
 These wastes have significant adverse effects on environment, some
have little impact, and others are actually beneficial.
 In virtually, the adverse impact can be minimized or eliminated through
the implementation of proper waste management.
 proactive approach to managing operations and become educated
about those, potentially harm the environment
 proactive approach involves adopting an attitude of environmental
responsibility; to protect the environment while doing the business.

4. Overview of environmental issues
Sources of wastes:
Environmental Impact of Wastes:
Waste Migration:
Managing Wastes:
Waste Treatment Methods:
Waste Disposal Methods:
Environmental Regulations:

5. Sources of wastes:
 These wastes fall into 1) produced water (98%) 2) drilling fluids+
cuttings (2%) 3) other associated wastes (negligible)
 Produced water contains impurities which can adversely impact the
environment. These impurities include DS(salts, heavy metals),SS
(organic materials), formation solids, H2S, CO2, low level naturally
occurring radioactive materials (NORM).
 Additives like coagulants, corrosion inhibitors, emulsion breakers,
biocides, dispersants, paraffin control agents, and scale inhibitors are
often added to alter the chemistry of the produced water.
 Water produced from EOR projects may also contain acids, oxygen
scavengers, surfactants, friction reducers, scale dissolvers.

6.  Drilling wastes include formation cuttings & drilling fluids.
 Water based drilling fluids contain viscosity control agents (clays), density
control agents (barium sulfate or barite), deflocculants (lignite), caustic
(NaOH), corrosion inhibitors, biocides, lubricants, lost circulation
materials, formation compatibility agents.
 Oil-based drilling fluids diesel & synthetic oils. DF s contain heavy metals
like barium, chromium, cadmium, mercury, lead.
 Associated wastes include the sludges and solids that collect in surface
equipment and tank bottoms, it wastes, water softener wastes, scrubber
wastes, stimulation wastes, wastes from dehydration & sweetening of NG,
tpt wastes, contaminated soil.
 Another waste stream is air emissions. These arise from ICE, used to
power DRs, pumps, compressors, boilers, steam generators, natural gas
dehydrators, separators.
 Large scale HC contamination of the sea (3.2mmts/yr) Table 1.1
 Oil production from offshore platforms contribute less than 2% of the
total amount of oil entering into sea.

8. Environmental Impact of Wastes:
 Toxicity to exposed organisms: Its conc. in water that results in the
death of half of the exposed organisms within a given length of time.
 The conc that is lethal, the test is called LC50 (high values). Sub-lethal
effects, the test is called EC50.
 The toxicity of aromatic HCs (10 ppm) is relatively high while paraffins
is low. HCs less than 1 ppm in water have a sub-lethal. High mol wt
paraffins are nontoxic.
 Chronic exposures of entire ecosystems to HCs, either from natural
seeps or from petroleum facilities have shown no long-term impact,
have all recovered when the source of HCs removed.
 Stunted plant growth if HC conc in soil is above 1% (wt), lower conc
enhance plant growth.
 Toxicities (LC50) of water based muds, small % of HCs can be a few
thousand ppm where as polymer muds can exceed, highly lethal.
 The toxicity of heavy metals limits or stops normal biochemical
processes in cells. General effects include damage to the lever, kidney,
reproductive, blood forming or nervous systems.
 Heavy metal conc allowed in drinking water below 0.01 mg/l

9.  The primary environmental consequences of air pollutants are respiratory
difficulties in humans and animals, damage to vegetation and solid
acidification. Release of H2S can be fatal to those exposed.
Waste Migration:
o The environmental impact of released wastes would be minimal if the wastes
stayed at the point of release; most wastes migrate to affect a wider area
through groundwater along the local hydraulic gradient.
o For release at sea, waste will follow the winds and currents. For air
emissions, the pollutants will follow the winds. Because migration spreads
the wastes over a wider area, the conc can be reduced by dilution.
Managing Wastes:
• To develop and implement an effective waste management plan. Identify the
wastes and list the best way to manage, treat, dispose of those wastes
• An environmental audit to determine whether existing activities are in
compliance with relevant regulations.
• Effective method of process to minimize the waste to be selected.
• Reuse or recycle and recover voluble components or use of wastes for useful
purposes through innovations.
• When properly managed, the risks and hazards of drilling and production
operations can be reduced to low levels.

10. Waste Treatment Methods:
 The waste treatment method selected, however, must comply with all
regulations, regardless of their cost.
 Segregate the wastes into their constituents, e.g., solid, aqueous, HC wastes.
 Shale shakers, separation tanks, heater treaters, hydrocyclones, filter presses,
gas flotation systems or decanting centrifuges can be used on need basis.
 An emerging technology for HC removal from contaminated solids is
bioremediation. Other treatment methods include distillation, incineration,
solvent extraction, critical/supercritical fluid extraction.
 Non-HC aqueous wastes: Ion exchange, precipitation, reverse osmosis, evopn.,
biological processes, neutralization & solidification ( to remove DS from water).
Waste Disposal Methods:
• The disposal methods depend on composition & regulatory status of the waste
• Injection of produced water into injection wells of water flooding or EOR
projects after treatment subject to state regulations.
• The primary disposal methods for solid wastes are to burry them or to spread
them over the land surface.
• Bioremediation is promising method to disposal of oil contaminated soil which
will convert into more fertile soil within 4 to 5 months.

11. Environmental Regulations:
 The need to minimize environmental impact, the number of regulations
governing drilling and production activities have been increased.
 Most of these regulations impose economic fines and possibly criminal
penalties for violations. This increased the cost of industry operations.

12. A NEW ATTITUDE

13. • Environmental harm is there during E&P operations. There must be balance
between human activities and benefits of those activities. Effective technical
options are available to minimize the risks but options are expensive.
• All companies including oil companies exist by the grace and will of the people
in society. Through legislation, litigation, or economic boycotts these
companies can be closed down if the people do not wish, not necessarily based
on accurate scientific information.
• This may be due to lack on understanding scientific environmental principles.
• The transfortation of imported crude oil creates a much greater hazard than
domestic production.
• Mutual education between regulators, the pet. Industry and the public at all
levels is an important step I environmentally responsible cost-effective
operations. This partnership requires cooperation, team work, commitment,
credibility and trust among all parties involved in E&P co.s
• The related activities must be oriented toward improved environmental
awareness and protection, not the avoidance of responsibility for
environmental protection.
• Environmental awareness must be an integral art of everyone’s daily job.
• API , member companies has developed some guiding principles.

16. DRILLING AND PRODUCTION OPERATIONS
Drilling and production operations generate a significant volume of waste for
which industry has developed many technical and scientific methods to
minimize or eliminate the environmental impacts as on today.
DRILLING: Overview of Drilling Process:
 Generate a variety of wastes called, drilling cuttings, drilling fluids and its
associated additives. Drilling fluids mostly reused which reduces the wastes.
 The base fluid is water, followed by oil, air, NG, and foam. (water based, 85% or
oil based fluid called mud). Reserve mud also kept ready to meet mud loss.
 Pits are also used to store water, waste fluids, cuttings, rigwash etc.
 Air emissions from the ICE used to power the DR.
Drilling fluids:
 The primary purpose of drilling fluid is to remove the cuttings, additives to
increase the viscosity or density of the fluids on need basis.
 Additives to increase the lubricity of the fluid are commonly used.
 Many new additives have been formulated to lower the toxicity or
environment friendly fluids which reduces the impact damage.


17. A typical elemental composition of common constituents of water based drilling
muds is given in table 2.1.
* Hydratable clays mostly bentonite (3 to 7%) used to increase viscosity;
* Lignites, lignosulfonates, used as deflocculants at high temps (for easy pumping)
* Barite (BaSO4) has high sp gr of 4.2 used foe density control of drilling fluids.
* Cane fibers, groundnut shells, cottonseed hulls, saw dust: for lost circulation;
* pH control, lubricants, Corrosion inhibitors, Biocides, FD control

18. Oil based Drilling Fluids:
o These fluids are used for high-temp wells; wells containing water sensitive
minerals; wells containing reactive gases like CO2, H2S.
o Oil based muds are generally more expensive and greater potential for adverse
environmental impact. But more benefits are there, faster drilling, reuse of
muds after reconditioning, which in turn lowers the damage effect.
o The unwanted components like heavy metals, salt & HCs also harm.
o The potential impact of drill cuttings can be significantly reduced by separating
the solid cuttings from the more toxic mud.
o Preparation of drilling and production sites can cause local impact on the
environment, like erosion, soil compaction, sterilization. Heavy equipment can
compact the soil. If the well is abandoned, restoration of land is also problem.

19. Production
 The largest waste stream is produced water, with its associated constituents.
 In GGS produced water gets separated along with traces of oil. Emulsion oils
need to be treated with demulsifiers. Some more chemicals are to be to treat
this produced water before disposal
 Some solid sediments also accumulates in separators, heater treaters, oil
storage tanks which need to be treated, dried before disposal as per
regulations. Oil soaked soils or the well site pits are also to be treated.
 Advanced water treatment methods are available to lower the HC levels.
 The current US Environmental Protection agency limits for the discharge of HCs
in water for the best available technology are 29 mg/l on a monthly average
and 42 mg/l for a daily max.
 Produced water is invariably oxygen depleted. If discharged oxygen depleted
water can impact fauna requiring dissolved oxygen for respiration.
 Produced water can be highly corrosive to production equipment because of
dissolved oxygen, carbon dioxide, hydrogen sulfide gases.
 Scale inhibitors, biocides, coagulants, foam breakers, surfactants etc. regularly
used in the various processes of production.

20. Well stimulation services:
 Well activation jobs like air compression, oil displacement, nitrogen
displacement, foam displacement, nitrified foam are being used.
 Well stimulation jobs, like acidization, hydro-fracturing.
 The above operations may be taken directly or through CTU (rigless operations)
 In due course of production the wells cease due many wellbore problems.
Some times wells are required to be cleaned, unloading of water etc.
 To improve the permeability acidization/ HF are required to be carried out.
 In these jobs organic/inorganic acids like hydrochloric, formic, acetic,
hydrofluoric acids and many additives are also required to added . The spent
acid is to be washed back to the surface. Acids are highly corrosive.
 Wettability agents can also add to change the wettability after the job.
 Various types of chemicals used in the activation/ stimulation jobs will come
back someway through oils/waters which in turn impact the environment.
 The N gas contains many impurities like water vapor, CO2, H2S, CO which are
required to be removed through specific processes.
 Waste waters from cooling towers, water softening wastes, contaminated
sediments, scrubber wastes, used filter media, lubricants are other wastes.

21. Radioactive Materials:
Many drilling sites and production facilities have radioactive materials associated
with them. Primarily radioactive tracers or logging tools are deliberately brought
to the site for use while other materials are naturally occurring and are called
naturally occurring radioactive materials (NORM).
AIR EMISSIONS:
 A wide variety of air pollutants are generated and emitted during the drilling &
production operations. These include oxides of nitrogen (NOX), volatile organic
compounds (VOCs), oxides of sulfur (SOX) and partially burned HCs (CO, etc.).
 Halon gases are used at many drilling and production sites for suppression. These
gases have been identified as an ozone-depleting chlorofluorocarbon (CFC).
 The largest source of air pollution is the ICE used to power drilling & production
activities like rigs, compressors, pumps with NG or diesel fuel. 3.5 lbs of NOX can
be generated for each bbl of fuel burned.
 As per API 1979, the NOX emitted are from, Gas processing activities: 46%,
production activities: 21%, refineries: 22%, Crude oil Tpt: 5.2%, onshore drilling:
4.2%, product Tpt: 0.9%.
 About 25 lbs of formaldehyde & 1.5 lbs of benzene can be generated per MMCF
of fuel burned. Fuels benzene, ethylbenzene, toluene, xylene (BETX), about 3% of
those compounds will pass through the engine and be emitted.

22.  Another major source of pollutants is from HT, boilers, steam generators. They
also emit NOX & partially burned HCs like CO.
 Production operations that can cause emissions include the use of fixed roof
tanks, waste water tanks, loading racks, fuel gas from thermal recovery process.
 Three major sources of volatile HC emissions from these tanks: breathing losses,
working losses & flashing losses due to temp, pr, level changes in the tanks. Open
tanks, sumps, pits can be sources of volatile emissions, depend on ambient temp.
 Transfer of oil from tanks to trucks also another source of volatile emissions.
 Flue gases like CO2, N2, CO, SO2 also produce during thermal recovery methods.
Fugitive Emissions:
 These fugitive emissions are HCs that escape from production systems through
leaking components like valves, flanges, pumps, compressors, connections,
hatches, site glasses, dump level arms, packing seals, fittings and instrumentation
 Improper fitting, wear & tear, corrosion may be the reason for leakages.
 A breakdown of how often each type of component leaked is given in Tab 2.11.
 Generic fugitive emission rates for well production facilities are given in Tab 2.12.

26. Emissions from Site Remediation:
 Another source of air pollution is from the cleanup of petroleum contaminated sites.
 Many cleanup practices for HCs spilled on result in volatile HCs being emitted into
the air and transported from the spill site.
 The most common HC spilled that causes air pollution is gasoline.
 To estimate the pollutant levels associated with 3 types soil extraction, vacuume
extraction, and air stripping.