Is anybody aware of available statistics relevant to hot tap activities on gas pipelines (e.g. how any done in the last years, how many failures, etc...)?
US DOT/PHMSA maintains statistics on "reportable" accidents involving gas pipelines within the USA. There have not been any hot tapping accidents reported within that data that I have seen.
Not something that anyone would keep track of. I've done about 20 (that I can remember, mostly they are non events that are not memorable) in 36 years. I bet BigInch and LittleInch have each done more than that. There are certainly people here that have done even more than the three of us. No one has kept an industry census.
LittleInch,
I can't believe you really want an answer to that. Hot taps are just another "it is not zero risk so we'll ban it" topic like screwed pipe and pneumatic testing. All the piping codes allow NPT threaded connections but the same companies George is talking about ban them. There is no requirement to do HazOp analysis on low consequence projects but those companies spend millions of dollars doing them. etc.
I worked for one of those companies and was able to run my own show and thumb my nose at the silliness (for a lot of reasons, not the least of which was my operation made tons of money and was the most profitable operation in the company worldwide) and produced natural gas for a direct cost of $0.04/MSCF in a $10/MSCF sales market. My replacement bowed to the corporate will and when she was laid off those same wells had a direct cost of $5.20/MSCF (in a $2.80/MSCF market). Sad thing was that her lay-off had nothing to do with the field's profitability. Stupid is not without costs.
I don't think those particular companies that instituted the hot tap ban had any direct thoughts about "it is not zero risk so we'll ban it", rather it was more like, during their infancy, they thought they had enough local expertise to attempt one or two and one or two went badly wrong. Hot taps are common and a bit dangerous, but can be really dangerous when you don't know what you're doing. TDW, on the other hand, can do them blindfolded in a coal bin.
CostaV,
Those are fascinating reports, thanks for sharing. They have a category called "Hot Tap made by error" and it means that someone hot-tapped the wrong damn line. In the 2015 report that category is 6% of the total. Failed hot taps in the correct line do not have a category. I suppose that people really are just too stupid to be allowed to use the hot-tap process. But without it, to do a tie in you would have to cut in a tee, wouldn't the error then be far worse (making a full diameter cut in a line you thought was blown down but wasn't)?
3.3.3.4
Relation between hot tap made by error , size of leak and design parameter
The term “hot tap made by error” means that a connection has been made by error to the gas transmission pipeline, assuming it was another pipeline.
I think the "hot taps made by error" should be included in the "External interference", just in a separate sub-category.
