Rank: Guest 
|
Posted By Chris Harrison
is there a genuine need for breathing apparatus on a drill ship for all crew members or just the deck drill crew, or would it be more practical to issue all crew members a rescue/hood gas mask suited to H2S environments.
i understand that H2S can be toxic/lethal in high enough concentrations, which the drill crew are unlikely to meet in the proposed operations/duties.
however a risk assessment has realised there is a small chance of "shallow gas" which i have been asked to plan around, i believe that it would literally be for emergency use only until the ship could be closed down and vented or move out of harms way. the vessel has many H2S monitors and alarms fitted and tested.
|
|
|
|
|
|
Rank: Guest
|
Posted By stephen d clarke
Hi,
H2S Hydrogen sulphide would be best described as extremely flammable and very toxic by inhalation (and very toxic to aquatic organisms). It has WELs short term exposure level of 10ppm and a long term exposure level 5ppm (comparable with hydrogen cyanide). It is detectable at very low concentrations but I believe it quickly numbs the sense of smell, fatalities have and do occur e.g. a landfill waste sites. It doesn't take prisoners despite its reputation in the school kids stink bomb.
Steve
|
|
|
|
|
|
Rank: Guest
|
Posted By FAH
Hi Chris
H2S is indeed a very dangerous gas but you don't need the chemistry lesson here.
Your question about "breathing apparatus id less easy to answer until you clarify whether you're referring to the Emergency RPE or ELSA for escape to a safer place [normally a "safe haven"]; or the self contained breathing apparatus similar to the kit that firefighters use.
Given your post content, I suspect that you're probably thinking of the ELSA. In this case you will possibly find a great deal of [generally unwarranted] resistance to the use of hoods as the offshore industry remains convinced that the way it's always been done is still the only way even with modern kit.
Personally, I would generally go for hoods for all circumstances other than for emergency response teams for a whole host of very practical reasons.
Hope this helps. If you need more just get my contact details from IOSH & drop me an email.
Frank Hallett
|
|
|
|
|
|
Rank: Guest
|
Posted By A Campbell
Chris,
If memory corrects me this should be in part of the safety case that uk drilling contractors/operators have had to have in place for some years.
There are various companies that specialise in supplying equipment for such circumstances and would be a good starting point to look at also.
You will need to have a plan of monitoring, alarm systems and response required.
The response could be the monitoring of wind and have alternative muster points depending on direction.
SCBA sets for emergency crew & rescue, elsa or equivalent for crew escape.
Air line system & refill system at muster points and working area e.g. drill floor.
There is a lot (too much) to look at for planning and having systems in place that could be written on here! Further advice is required!
|
|
|
|
|
|
Rank: Guest
|
Posted By CJP
I agree with A Campbell with regard to breathing apparatus and specialist advice from a H2S service company. Remember that with any shallow gas the time to surface will be short so the opportunity to close in the well or move off location will be limited. Returns to sea bed in the top hole section and drilling a small diameter pilot hole are also options.
|
|
|
|
|
|
Rank: Guest
|
Posted By Robert K Lewis
We can always do well to remember that H2S is around half the toxicity of Hydrogen Cyanide gas. It is not about needing high concentrations to be dangerous. Because of its anaesthetic effect on the olefactory organs however, at around 30ppm, it can be far more difficult to deal with. The primary risk areas are always going to low points that are enclosed to prevent free ventilation as the gas is about 20% heavier than air. It is not the actual number of monitors that are important but rather their proper location.
I would always have self rescuers issued to all persons within identified risk areas.
Bob
|
|
|
|
|
|
Rank: Guest
|
Posted By dave burrage
Hi Chris
This is an area which has some well established 'standards' and safe working practices. If you want to give me a call, i am sure i can give you some guidance to realistic measures you could take.
Rgds
|
|
|
|
|
|
Rank: Guest
|
Posted By Jim T
Chris
An interesting question, which really depends on the well you are drilling.
From normal drilling operations I would suggest that escape hoods / respirators which offer protection from H2S are available to the crew in their cabins and areas of work away from flare booms and the Derrick. For those who may be exposed without warning or in high concentrations then full BA should be available at all times and the personnel it relates to trained and competent to use it.
On a well where there is a high risk of H2S release then ALL crew should be issued full BA (15 min Escape or 30 min Work/Escape sets) along with the temporary installation of a Cascade system, allowing personnel to continue work in event of a H2S release or to safely attend their Muster Station in event of an incident involving H2S .
I have never worked on a drill ship, but assume that the main accommodation module has a positive pressure system to prevent the ingress of harmful gases?
It all boils down to what is predicted to come up from the well itself.
Does this help?
Jim
|
|
|
|
|
|
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.