# BOL's, near oil and gas wells? Hydrogen Sulphide, are you at risk?



## jro1 (Mar 3, 2014)

Living in a oil and gas rich province or state

I am sure almost everybody knows where and what Alberta is all about. Alberta is my home province, It has spectacular views, Rocky mountains, fresh water and the hunting is good and plentiful. However Alberta is also home to some of the biggest oil and gas reserves in the country. Where I live in central Alberta, there approx 30-40 wells in one township alone, sometimes more! One of my biggest concerns is an H2S leak after SHTF. Most newer wells within the last 5 years are completely automated, and can be remotley accessed on a computer by the operator in the big city. most wells are regulated and operated remotely which means valves can be opened or closed from the head office. During a SHTF event, the operators would shut in the well depending on the severity of the event, some wells need possitive air to hold major valves open, if the air is shut off, the main valves will close and shut in the well completely, so there would be no need to worry about poisonous gases releasing to atmosphere, so long as the wellhead and valves are not damaged by people or rusting out over the years. If you live near or have a BOL near any well locations, make sure you know what type of well, is it producing H2S? is it remotely managed or does it require an operator to manually control the well? This is very important information to know! A few things you can do to protect yourself are, Taking an H2S Alive course, Some online reading while taking notes, arming your self with a personal gas monitor, and keeping a SCBA(Self Contained Breathing Aparatus) around at all times, or simply relocating to an area with little or no gas and oil activity. During a SHTF event, if you encounter the smell of rotten eggs, move upwind and cross wind from the source, moe to higher ground, and get the heck out of dodge, H2S is extremelly lethal, it kills the nervous system, will kill your sense of smell(by that time it is too late) and the body simply shuts down, no recovery at this point! If you live near a sour location during SHTF, If properly equiped with a gas monitor and air pack, you can mask up and shut in the well, by closing the Master valve, which is located inline on the bottom of the well. shuting in the wells during an event might be good practice if they are on your property or near your property. H2S is nothing to mess around with, nor is an out of control well be it natural gas or oil, I would think that during a SHTF event, there will be thousands of out of control wells around the country, some may be blow outs, others may just be leaking gasses. If you are handy with pipefitting, you may even tie yourself into a natural gas well and heat your house all winter for free! here is some basic info on H2S and also a well schematic to familiarize your self with the master valves. If I have missed any good info, please add to the topic!

H2S Safety Factsheet
August 2004

Hydrogen sulfide (H2S, CAS# 7783-06-4) is an extremely hazardous, toxic compound. It is a colourless, flammable gas that can be identified in relatively low concentrations, by a characteristic rotten egg odor. The gas occurs naturally in coal pits, sulfur springs, gas wells, and as a product of decaying sulfur-containing organic matter, particularly under low oxygen conditions. It is therefore commonly encountered in places such as sewers, sewage treatment plants (H2S is often called sewer gas), manure stockpiles, mines, hot springs, and the holds of fishing ships. Industrial sources of hydrogen sulfide include petroleum and natural gas extraction and refining, pulp and paper manufacturing, rayon textile production, leather tanning, chemical manufacturing and waste disposal.

Hydrogen sulfide has a very low odor threshold, with its smell being easily perceptible at concentrations well below 1 part per million (ppm) in air. The odor increases as the gas becomes more concentrated, with the strong rotten egg smell recognisable up to 30 ppm. Above this level, the gas is reported to have a sickeningly sweet odor up to around 100 ppm. However, at concentrations above 100 ppm, a person's ability to detect the gas is affected by rapid temporary paralysis of the olfactory nerves in the nose, leading to a loss of the sense of smell. This means that the gas can be present at dangerously high concentrations, with no perceivable odor. Prolonged exposure to lower concentrations can also result in similar effects of olfactory fatigue. This unusual property of hydrogen sulfide makes it extremely dangerous to rely totally on the sense of smell to warn of the presence of the gas.

Health Effects of Hydrogen Sulfide

H2S is classed as a chemical asphyxiant, similar to carbon monoxide and cyanide gases. It inhibits cellular respiration and uptake of oxygen, causing biochemical suffocation. Typical exposure symptoms include:

LOW: 0 - 10 ppm Irritation of the eyes, nose and throat

MOD: 10 - 50 ppm Headache, Dizziness, Nausea and vomiting, Coughing and breathing difficulty

HIGH 50 - 200 ppm Severe respratory tract irritation, Eye irritation / acute conjunctivitis, Shock, Convulsions, Coma, Death in severe cases

Prolonged exposures at lower levels can lead to bronchitis, pneumonia, migraine headaches, pulmonary edema, and loss of motor coordination.

Working with Hydrogen Sulfide

Most countries have legal limits in force that govern the maximum allowable levels of exposure to hydrogen sulfide in the working environment. A typical permissible exposure limit in many countries is 10 ppm. While the distinctive odor of H2S is easily detected, its olfactory fatigue effects mean that one cannot rely on the nose as a warning device. The only reliable way to determine exposure levels is to measure the amount in the air. Regular monitoring will help to identify areas and operations likely to exceed permissible exposure limits, and any areas that routinely pose overexposure hazards should be equipped with continuous monitoring systems.

With a vapor density of 1.19, hydrogen sulfide is approximately 20 percent heavier than air, so this invisible gas will collect in depressions in the ground and in confined spaces. The use of direct reading gas detection instrumentation should be required before entering confined spaces such as manholes, tanks, pits, and reaction vessels that could contain an accumulation of H2S gas.

Wherever possible, exposure should be minimised by employing adequate engineering controls and safe working practices. Such methods include ensuring good ventilation and changing work procedures and practices. Where engineering controls cannot adequately control levels of exposure, it may be necessary to supplement them with the use of suitable personal protective equipment (PPE) such as supplied-air respirators. A qualified industrial hygienist or safety professional should be consulted for guidance on the suitability and correct use of respirators.

Should a co-worker ever be overcome by H2S gas, do not attempt a rescue until you are properly protected yourself. The rescuer can very easily get caught out by venturing into a confined space without adequate protection. Remember that at levels above 200 ppm, collapse, coma and death due to respiratory failure can occur within seconds after only a few inhalations so you can be overcome yourself very quickly. Such incidents are sadly all too common and only serve to make the rescue effort twice as difficult.


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## thepeartree (Aug 25, 2014)

I think it depends a great deal on what the shtf event is. Living surrounded by small gas and oil wells as I do, I can tell you that normally there is no leakage at all, liquid or gas.


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## jro1 (Mar 3, 2014)

thepeartree said:


> I think it depends a great deal on what the shtf event is. Living surrounded by small gas and oil wells as I do, I can tell you that normally there is no leakage at all, liquid or gas.


But sour wells rely on injection of inhibitors to prevent corrosion, when no one is managing these wells, We will see leakage big time! wouldnt you agree?!?!


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