Private Forums
Casing Drilling UK/Norway/Denmark
13 December 2006
Tesco is introducing casing drilling to this theatre of operations
and would like some feedback as to which casing sizes would
operators be most interested in seeing introduced.We are currently
drilling 7 3/4 and 10 3/4 casing in Norway.

Regards,
Lyle
8 answer(s)
a050488
DSL (Drill Site Leader)
Abu Dhabi Marine Operating Company
Total Posts: 46
Join Date: 20/04/11
Dear colleagues

It has  been interesting to read this thread, but I would really like some assistance with my original question relating to a drive sub for 20" casing drilling.

In fact we are also looking at casing drilling with 34"!! Both casing threads will be either ACME or BTC.

Can you advise the companies that supply this type of equipment, perhaps even with a drawing. We are interested in whether the item is welded at the crossover points from larger to smaller OD (or one piece construction non-welded), and specific QA/QC requirements and operating practices/experience.

Thankyou very much

Ahmed Salem
a050488
DSL (Drill Site Leader)
Abu Dhabi Marine Operating Company
Total Posts: 46
Join Date: 20/04/11
We are designed saver sub from 20" casing to 5.5" - the bottom connection of saver subs is start connection similar to acme thread and it is crossed by welding to 5.5" f.h connection for drill and total length is 14 ft each size has 7 ft length. In fact it is under manufacture. It is plan to drill with 20" casing and rotate with top drive using 5.5" drill pipe at rotary table. Please if you have any advice or what will be happen while drilling using this saver sub. Or based on your advice we can change the design.
1vartecheng
Managing Director
Vartech Eng
Total Posts: 16
Join Date: 06/07/15
For Sean,
I was not able to find the info on the connection used by Tenaris in their Water bushing for CWD. If not mistaken, probably it was TXP buttress.  They have used wedge threads (i.e. TSH523) for other applications with CWD as well.

However, test went very good, and they presented themselves as a CWD alternative to other companies, which I think is good.

Thanks,
Reynaldo @ Bogota


AndyPua
Drilling Consultant
PT Drilling Services
Total Posts: 60
Join Date: 15/09/14
We had done drilling with 13-3/8" Casing in 2013 with 17-1/2" Bit. Service company is Weatherford. Casing is buttress thread. 
There is a special saver sub to make up onto the casing. Took a while to rig up, but worth the time. It make up the TDS to casing and then casing pin to the casing below. 
It saves the tripping time and no requirement to control ROP in soft formation. ROP is between 100m/hr to 150 m/hr. There is no worry about hole cleaning because Annulus Velocity is really high (remember the annular area now is between 13-3/8" x 17-1/2" hole). 
Once we get to TD, circulate and straight to cementing. 
TDS alignment to Rotary Table has to be really straight. As a precaution, do keep the power tong as a back-up. Sometimes the bottom plug diaphragm can plug up bit nozzles once it is sheared during cementing. 

  
Sean_Byrne
Senior Drilling Engineer
Dubai Petroleum
Total Posts: 25
Join Date: 02/04/08
Thanks RV,

Do you know which thread they've proposed ?

WEDGE, i'd assume ?

What torque (and drag - TDS weights anticipated) are being used for the trial ?

Thanks
Sean
  
1vartecheng
Managing Director
Vartech Eng
Total Posts: 16
Join Date: 06/07/15
Sean,
The large "Saver sub" or "Water bushing" to drill with casing using the TDS has been developed and started to be tested an used by Tenaris, for 9-5/8", as showed by them to us in Argentina in 2014.
Thanks 
RV
Sean_Byrne
Senior Drilling Engineer
Dubai Petroleum
Total Posts: 25
Join Date: 02/04/08
Anyone have thoughts on a large OD saver sub, with robust thread make and break (dope or no dope), s"WEDGE"d back to TDS connection ? Has anyone ever done this before ? Essentially a "water-bushing" capable of multiple make and breaks ?
Sean_Byrne
Senior Drilling Engineer
Dubai Petroleum
Total Posts: 25
Join Date: 02/04/08

I know this post's old, and the technology advanced. But I have a 'dumb' question:

If i keep true to the KISS principle (Keep It Simple Stupid).

  • Why not drill with casing, directly attached to the TDS ?

I hypothesize (if for now, you  could allow me my paradigm(s) and oilfield terminology”¦)

Currently, extracting Oil and Gas from deeper in the subsurface requires us to case off and isolate ”˜zones of interest´. Then should we focus on the enabling technology - a conduit (a straw in a sponge) !?

  • Why can´t we run a single length of the required inner diameter straw in the hole (i.e. the monobore concept”¦) ?
  • Is it, fundamentally we cannot design a single straw with the required mechanical properties to ”œdrill” to the required depth(s); being exposed to the huge variety and uncertainty of stresses associated with lots of ”˜known, unknowns´ ? And thereafter reinstate (or enhance - stimulate) the mechanical properties of the rock for maximum production ? In doing so,

  • where zonal isolation is required; ”˜isolate´ (seal) off the required zones, be it by mechanical expansion (expandables) and or by filling the void with some other impermeable substance (cement, rubber, etc etc)

  • where the desire is to produce, we should be using ”˜non damaging´ methods to preserve rock properties and or thereafter reinstate / enhance the mechanical flow properties (gravel packing, stimulation / fracking, permeable fluids/cement that recognise hydrocarbons and block water / non desirables - ...etc etc)

I digress

  • If therefor, we cannot run a single length of straw (Coil Tubing) in the hole and achieve our zonal isolation requirements, we must therefor run a tapered straw, with multiple ”˜connections´. Efficiency dictates how we join the straw:
  • is it efficient to weld and maintain / enhance material properties, or
    1. use (premium) threaded connections (with or with or with dope now, if that´s what it takes to reduce make up friction / damage) ?   

 

As a stepping stone for now, assuming using metal / steel is a value driver; can we design a casing connection robust enough; with sufficient fatigue resistance, and with the durability required of multiple make ups / break outs, such that we ”˜invent´ the ”œTop Drive Saver Sub” that allows us to Drill With Casing ?

 

That or ”œdrill with lasers”, assuming that does not require the straw to have such ”˜onerous´ mechanical properties ?

http://www.zerlux.com/products/laser-drilled-laterals

This company did a big show and tell for Aramco in 2007, and it was supposed to be game changer.  But never took off !? Impact on the Steel Industry ? Know-how coming from the wrong country ??

 

Too many questions - answers only required for no on a saver-sub with a ”œlarge” OD premium connection, capable of multiple make and breaks please”¦that or what am missing out on (prefer smart answers if it's a dumb question) ?

Thanks

Sean


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