Rotating a liner to TD that's still being made up

[DrillerNic]

I've got an unusual liner on my next well- when the liner shoe reaches open hole, we'll still have 2000ft of liner to run. I'm wondering how we can ream this liner in while we're still running it! The Tesco Casing Drilling thing will be difficult due to stack up height on the rig...I'm thinking of connecting a water bushing on the top drive, making up a joint, connecting the bottom connection of the water bushing, reaming, undoing the water bushing and making up the next joint and so on.

Anybody got any other ideas?

 

[coolbreeze]

Why not under ream the open hole the extra 2000 feet to ensure the liner goes in without getting stuck? Is there any formation issues or dog legs that are giving you problems? I thought this was standard practice when running a casing string back to surface?

Frank

 

[DrillerNic]

Coolbreeze, thanks for your reply! The issue here is where we think the hole is in good condition (circulate hole clean before pulling out, no drag pulling out etc) and then find we have to ream the liner in....

Pulling out and underreaming (or simply doing a wiper trip) is not preferred because:

1) it's a singles rig and we have to lay down pipe rather than rack pipe so round trips etc take forever
2) we're using Oil Based Mud, and in the North Sea we have to have total containment of cuttings with OBM, so underreaming would mean more cuttings, more skips, more logisitcs headaches...
3) the company had a bad experience with a bicentered bit last year and so we can't drill an over gauge hole to start with using a bi centered bit.

 

[coolbreeze]

I don't know what you are calling a water bushing but I assume it is some type of cross-over between drillpipe/ (top drive connection) and the casing connection. I have designed these before, nothing to them really but I would be especially careful about over-torque reaming in the hole. If you have the connections, let me know and I will draw something up, run the numbers, and give you torque/burst specifications along with a drawing for an X-over. Also include any clearance issues, like minimum length necessary for make up on the top dirve.

Frank

 

[jeffob]

Hughes has a PDC bit that will make up to the bottom of your pipe. It has a full PDC cutting structure, is steel bodied, and drillable after it is set with either a steel tooth bit or a specialized PDC. Cementing is done through the bit nozzles, and there is a rupture disk for safety if the nozzles plug off. You shouldn't have any problem rotating the casing with the water bushing crossover, it has been done before a number of times. One thing to keep in mind is you are going to be generating torque in the casing string, and as such will need higher torque couplings, ie buttress.

Jeff

 

[DrillerNic]

Thanks for everyone's replies!

We're just about to run the casing, with 2 specially designed water bushing (NC50 x VAM top HT crossovers), which are just the right length to be able to ream down a full casing joint ready just in case. We had the VAM top HT threads manufactured to the low end of VAM's recommended tolerances to reduce any threat of galling as we will be making & breaking the premium connection repeatedly. We've got a reamer shoe on the end of the string (called a Pen-o-trator shoe...god I love these roughty-toughty names vendors come up with!). We didn't see any hole problems while drilling, there are no big doglegs, the bit & stablisers were in gauge on POOH, and we've circulated multiple bottoms up to get any cuttings out, so I think we're in good shape....