Oilfield H2S Training

H2S is one of the deadliest and most dangerous gas that have claimed lot of lives in oilfield. If you are related to oilfield industry you would have heard about H2S definitely.

In any event H2S awareness can be the difference between life and death. H2S had killed and will continue to kill oilfield workers who are not properly trained and not properly prepared to perform their duties in this potentially lethal environment.

In oilfield the simplest most routine task can be deadly sometimes, so each and every task you perform should always go for a hazard check and control measures should be placed before starting the work.

Learning about H2S awareness would make a huge difference while working in oilfield.


I would be happy in answering the following about H2S

What is Hydrogen Sulphide ?

How H2S is formed ?

Where you can find H2S?

The dangers that H2S can causes

How to control the risks associated with H2S

Oilfield H2S Safety Training Manual

How to stay safe while working with deadliest, highly toxic Hydrogen Sulphide gas?

Advancements in technology has helped oil and gas industry in exploring deeper and unconventional reservoirs, to meet the increase in demand for petroleum products, operators are required to drill in sour gas areas where Hydrogen Sulphide (H2S) is present at high concentrations.

Hydrogen Sulphide is a life-threatening, corrosive, flammable, highly-toxic gas. The exploration and operations of such fields has to be undertaken at high precautions. H2S can claim lives at very low concentrations, and also it can cause severe instantaneous failure of high-strength steels and other metals while exposed, which would increase costs of already high cost ventures.

H2S exposure deaths, incidents are still happening, the highly toxic gas can takes lives in seconds if it is not detected immediately. Analysis shows the following are the main reasons for incidents in sour gas fields:

1.       Lack of knowledge that a H2S release could occur and potential consequences of H2S exposure.

2.       Due to the lack of awareness relating to the occurrence of H2S, there was in many cases, a lack of adequate preparedness to deal with the release of toxic gas.

3.       The lack of appropriate personal protective equipment (PPE) and suitable alarms led in a number of cases, to fatal H2S exposure.

4.       The lack of training regarding what is H2S, consequences of H2S exposure, procedures to work in sour environment, and using of personal protective equipment in case of emergency.

So there is a huge need to spread awareness about H2S and in this book you will be learning a lot about it.

The following topics about H2S will be discussed in this book:

1.       What is Hydrogen Sulphide (H2S)?

2.       What are the Health Hazards associated with H2S?

3.       Monitoring and planning in case of emergency

4.       Emergency rescue

5.       SCBA training

Following this level of H2S awareness training, you will not be asked to intentionally work in areas where H2S may rise.

If a job is likely to be affected by H2S, further physical training will be required in the use of breathing apparatus, other protective equipment and site specific contingency plans.

Chapter-2 what is Hydrogen Sulphide?

Hydrogen Sulphide/sulphite/H2S is a colourless highly flammable and highly toxic gas that is found as unwanted bi-product in many industries.

H2S is considered as poison, even in low concentrations, it can affect several different systems in body at once; respiratory system and nervous system are mostly affected.

H2S occurs naturally in

Petroleum

Sulphur and natural gas deposits,

Oilfield-drilling and production,

Petrochemical and refining plants

Manufacturing plants,

Laboratory operations

Water treatment plants

Underground mining

Chemical plants

Stagnant water

H2S is heavier than air, and can collect in low lying areas such as

Oil/gas well cellar deck areas

Open Drains

Oil/gas well returns lines

Sewers

Deep excavations

Approximately 90% of H2S sources are natural, H2S results from bacterial decay of animal and plant material in wet areas such as marshes and swamps.

H2S is formed in earth crust and escapes out in volcanic eruptions.

10% of H2S is caused due to human activities and this 10% is likely get exposed by humans.

Hydrogen Sulphide/sulphite/H2S also called as

Sour gas

Marsh gas

Sewer gas

Swamp gas

Rotten egg gas

Stink gas

Manure gas

Acid gas

Poison gas

Physical Properties of H2S:

H2S is heavier than air (1.189 SG)

H2S is soluble in water, liquid, drilling mud and only releases when the mixture is agitated

H2S is gas at ambient conditions

It is colourless

H2S is an invisible gas that smells like rotten eggs; however individuals should not rely solely on their smell to detect gas. The reason why you should rely on smell is other chemicals may mask the smell of H2S gas and also you lose sense of smell as H2S concentration increases.

High concentration of H2S can instantaneously lead to ability to smell.

H2S concentrations greater than 100 ppm paralyzes the sense of smell.

Continued exposure to low levels and high concentrations of H2S can cause people to lose their ability to smell the gas even if it is present.

H2S is easily dispersed by wind.

H2S is highly flammable; it will burn or explode at 500 deg F and above.

Explosive range from 4.3% LEL – 46% UEL (LEL- Lower explosive limit- is the lowest concentration of fuel in air which will burn, UEL- Upper explosive limit – is the maximum concentration of fuel in air which will burn)

H2S burns with a blue flame producing Sulphur Dioxide (SO2), it is purposely burned in flare stacks to help prevent accidental explosions and it will emit dangerous, toxic sulphur dioxide (SO2), which is twice heavier than air.

Exposure to SO2 can:

Severely irritate eyes, nose, throat and respiratory system.

Tissue damage if exposed long term

Freezer type burns when contacted with liquid SO2.

H2S auto ignition temperature is 206 deg C

Flash point at -82.4 deg C

 H2S is highly corrosive gas and will cause instantaneous failure of well equipment; H2S combines with moisture in air to form a corrosive acid which in high concentration can result in metal fatigue.

H2S affected tubular, pipes are subjected to hydrogen embrittlement/ Sulphide stress cracking and can release H2S from tubular and pipes carrying H2S.

H2S reacts very violently with

·         Strong oxidizers, metal oxides, peroxides.

·         Strong alkalis and active metals.

·         Some plastics and rubbers.