Oilfield Welding Practices

[KerfMurph]

Alright all you oilfield welders I need to find out something. When you are called out to cut off a wellhead when they are going to abandon the well how do you make sure the job will be safe? After all they have been producing oil and gas for who knows how long.
I'm really interested in when you go up to cut off the wellhead, sometimes they have the well completely open without any valves or a blowout preventer on it. Then they want you to cut some access holes in the outer pipe under the wellhead so you can reach in and cut and drop the inner pipe first and then finish cutting off the wellhead. What are some of the things you need to do to makes sure it is safe? If there is nothing coming out of the well casing is it OK to pass your torch over the top just to make sure there is not any gas coming out that might cause problems once you go down to cut the casing? How do you make sure there is not going to be a problem from the open well while you are doing your work?

Thanks

[Xtreme Fabrication]

I am not an oilfield guy by any chance, but I have seen is basically a flow jet torch on a pipe beveler on the well head. Now a flow jet is a ultra high pressure water jet mixed with a little sand. The water/sand mix will cut threw any material. Most guys who own flow jets used them for cutting stone. The nice thing about a flow jet is there is no flame, sparks and will not heat up the material causing warping.

[hpci1]

sounds fishy to me, normally when a well is plugged the tubing is removed from the well and the production casing is salvaged as well. Then all that is left to do is nipple down the well head and then cut the surface or conductor pipe. This is the short version didn't want to get to long winded

[IamVince]

We always had to plug it with cement if we were abandoning it.And if I was the welder I would pass my torch over just to make sure(I'm not)

[dave powelson]

Originally Posted by KerfMurph

Alright all you oilfield welders I need to find out something. When you are called out to cut off a wellhead when they are going to abandon the well how do you make sure the job will be safe? After all they have been producing oil and gas for who knows how long.
I'm really interested in when you go up to cut off the wellhead, sometimes they have the well completely open without any valves or a blowout preventer on it. Then they want you to cut some access holes in the outer pipe under the wellhead so you can reach in and cut and drop the inner pipe first and then finish cutting off the wellhead. What are some of the things you need to do to makes sure it is safe? If there is nothing coming out of the well casing is it OK to pass your torch over the top just to make sure there is not any gas coming out that might cause problems once you go down to cut the casing? How do you make sure there is not going to be a problem from the open well while you are doing your work?

Thanks

You should be asking 'How does API state this work to be done?' if your interest is in safety
and not in 'cheap and fast'.

[hotrodder_101]

In my years in the oilfield, we always per the regulations have a cement plug down hole below the mud line. They actually take a tool they call guns and go down and blow holes in the casing. Then they pump sement down and through the holes to permantely seal the well bore. Then they remove the tree. Now comes time to cut the doors in the outer casings to cut the inner casing. With the wellhead, there should be a valve on the side called a casing valve. You SHOULD at a minimum open it. If you would fill safer make them fill it with water. Open all the casing valves as you will have to start on the conductor. Next you simply cut doors in the outer casings and cut the inner casing in two. Make sure that they are tied onto the wellhead. Once the casing is cut unbolt if they haven't already the wellhead and remove then move to the next wellhead/casing. Then they will rig up a cutter to cut the casing 5ft. or so below the mudline. Job done.
Luke

[Johny5]

Look around on here
http://drillingclub.proboards.com/index.cgi

[weldingroper]

Just happened to do an old old SOB bout 2 months ago, nobody knew anything about it. The wellhead was removed the day before I got there and the two valves on the top were closed, when we cracked them open it released the pressure and went ahead and opened em up. Left about a 2 foot stub and reached around the outer casing and pierced through, that way if there is any gas between the two casings it's gonna flame away from you. Cut it off and lifted off and what was supposed to be mud was just a bunch of rocks; yup old well. Then cut the next two off using the same method. Left open overnite, next morning they pumped mud back down it. Leveled all the casings and welded a 1/4" plate cap over it, you could still hear a bit of gas bubblin out through the mud. But as long as the flame is burning outside the pipe when your welding your ok, when it sucks in the pipe for some reason then you might hit the ground. Good Luck!!

[grindel]

Use a lel meter to see what is going on!

[hobohilton]

I've removed (torch cut) well heads and reinstalled due to the casing cracking just below the spider ring that fits around the bottom of the well head.

The hole was loaded with HEAVY mud. A check for gas was performed. I did this one at night. When I'd wave my torch over the hole I could see a "swirl" of gas burn down into the hole........

I cut and prepped the casing and well head. Pre-heated casing as per spec and re-welded the well head back on..... Put the rig back to work...

Location was near Ramah, Louisiana..... 1979.

Thanks,

Hobo