Severe Vibration Drilling Top Hole
07 February 2012
While using a BHA with a 9.62m560XP Motor with a 1.5 Deg Bend.
Drilling Perameters: surface to 500 Ft: Bit 16", TFA .9In2, WOB 35-40 Klbs, Srrface RPM 40-60,Total Bit RPM 160-180, GPM 900-950, SPP, 1000-2000 Psi> While drilling this section drilling contractor is expieriencing severe surface vibration which in turn is causing problems to the top driveand other equipment in the mast. Has anyone ever expierienced this problem and how was it mitigated.
Not all the available shock subs are fit for purpose. Hence the qualification of available units by Rogaland Forskning.
The ones that did qualify would reduce the vibration up to 40%.
Shock subs work better with roller reamers or at least stabilisers in the bottom hole assembly.
As for the Agitator...... again......not a shock tool, this is a downhole oscillation tool ....to keep things moving when you are doing a extended/sticky set with a motor, the gentle vibration action keep the weight from stacking.....a product of Anderguage ..... now owned and operated by No Other Vendor. Please see attached FYI......
Sorry man I do not know where you get your info but most shock tools from reputable and (even some from not so reputable)companies are by-directional.
I do not claim to know everything but I am pretty much convinced that a energizer/accelerator/intensifier/slinger are all tools run above your drill collars and jar to store the pull energy thus allowing this force to applied to the stuck issue below the jar and not to shaking bits and peices outa the derrick and from the topdrive on short drill pipe strings and when drilling shallow. The popular misconception ..... that if the dog house aint shakin ....you aint jarrin hard enough is for the most part ....wrong.
But I digress, if you were to be using an engergizer/accellerator/intensifier/slinger as a shock or isolation tool you may quiet things down at surface but the string below would still be pile driving the bit on bottom, I do not beleive that is a condition conducive to a good bit run.... maybe good for me as I could get a dayrate fishing cones or junks of PDC bit....
Just my thoughts/ rant gentlemen, I am not a "technical sales / client representative" read salesman so I am just stating things as I see them after drilling and running tools for 35 years.... good fishin.
Hi Mike, I am very sorry, I did not see your reply. You can visit http://www.globalrentalsuk.com
The Energizer is also useful for mitigating vibrations in top holes as it works both up and down. The Shock Tool only works one way. The Energizer is always run on top of the jar so it does not reduce impact of the jar - should you need to use it.
And, yes, I have financial interest in the company.
You can also use any other Energizer.
Surface Jar.... for drilling? That is for downward impacts.... You must thinking of some other tool......
What's the lithology your are drilling through.?
Is this a straight or deviated well.?
If directional, Do you really need to build angle in this section.?
I assume you have a bunch of hwdp behind?
What where is your stabilization, what type of stabs are you using?
What kind of bit are you using?
E.g. What's the skew on the cones if an insert?
If pdc this could be a main contributor.
What's the resonant speeds for your pipe and or bha. Often these do coincide at such shallow depths.
The bha likely needs more G & J! . Rigidity and stiffness. 9.5 or even 11inch collars properly stabilized.If you want or need to drill with 50 to 60k on bits.Shock sub or harmonic isolation tool to decouple dampen an isolate vibration excitation causes and effects.
Slower or higher speeds may work.Pump more, get motor turning at different speed.
Drillsection vertically if you can with a rotary bah. Use reamers versus stabs.
Insert bit with little skew.
Principally you have to lock the bha up, turn it at the right speed and have lots of weight stiffness and rigidity to make decent hole.
If you run a jar then you must include an accelerator to dampen surface effects and allow jar to work as intendedalso.
I like the Agitator a lot, a very effective tool. The only downside I've experienced is that it can lead to premature, and sometimes severe PDM failure.
My comments are in addition to those made by others as I agree with them. Surface hole vibrations as you described are accentuated by enlarged hole where the BHA/drillstring is not well supported (stabilized against the wellbore wall). Take a second look at your hydraulics as I suspect a 0.9 TFA on the bit in such a "soft"/"unconsolidated" interval on a 1.5 deg motor bend will enhance hole washout. The high motor bend is a good source of torque and eccentric dynamics.
I would consult Gerrit van Wilpe [email protected]
He did have direct experience drilling hard rock both in Oman and Gabon.
Air Drilling, Pile Driving (Hamering or Vibration Technology/RESOTECH) were techniques used with success.
References (Just in case you like to try Public Libraries):
OTC 3735 (1980) Turbo drilling offshore Qatar
OTC 5422 Vibration Pile Driving
We experienced severe vibration drilling a development well in the North Sea through a formation called 'Devil's Hole'. We incorporated an Agitator from Andergauge in the BHA. This not only reduced the vibration but also resulted in a noticeable increase in ROP (possibly as a result of eliminating vibration). The offset data provided a very good comparison between BHA with Agitator vs BHA without Agitator -
Btw, I am not an Andergauge sales engineer!
All the best,
We just had the exact situation on a land rig in Canada. Adding a shock sub smoothed things out completely.
Have not worked in the N. Sea for a long while so maybe falling behind on technology. Would appreciate access to info on the Energiser/Accellerator you refer to.
Run an Energizer/Accellerator in the drill collars. It will mitigate vibrations in top hole. We do this in the North Sea all the time in 36" and 26"hole sections.
A drilling bumper sub (lubricated, pessure balanced type preferably) or a thruster placed above the BHA can isolate surface equipment from downhole vibrations.
Consultant ( sort of retired but keeping in touch )
In the early days of onshore drilling in the UK, shock tools ( Bowen Cushion Sub ) were used to reduce vibration in top hole sections. It also reduced noise when severe restrictions were placed on operations !
Is the vibration constant even when you vary parameters.?
Have run a Shock Tool in the string.?
A Kelly will be more forgiving to surface equipment.
A lot depends on your location and overall drilling campaign.
For example, surface hole boulders are common in some parts of the UK Northern N. Sea and you just have to "chew" through them carefully and adjust parameters to suit. Of course you don't have Toolface control on the motor, but only for short intervals. In that respect, why a 1.5deg bend and how is the MWD handling the shocks? I have found a bent sub (OK, old school) can give better directional results than an ABH in surface hole and yes, you can rotate, carefully. If it's only to 500ft then what are the directional requirements anyway?
If it's hard formation and you have an extended number of wells to drill then air drilling is an option and displace to mud prior to running casing. Admittedly, maybe expensive to set up (if feasible with your rig) but can be cost effective if you have enough wells to drill.
Otherwise, certainly run a Shock Sub and with a 9.5/8" motor you can run a 9.1/2" Shock tool.
Increase no. of DCs. Another way is to use a shock sub.
One other thing to consider is a surface jar (if you have the space to pick it up i.e. drillpipe at surface).
In extreme cases, you may need to consider hammer drilling top-hole.
I hope it helps
I presume it's a Land Rig and the formation is fairly hard, or has lots of boulders?
It's common under these circumstances for vibration to be a problem for the surface equipment and if changing the drilling parameters doesn't have an effect, then the best thing to do is run a Shock Sub in the BHA.
If that still doesn't work, then consider using a Kelly for the top hole section.