Private Forums
Use of Halliburton BHKA disconnect tool on P&A
07 December 2018


Drilling team is evaluating options to safely & efficiently abandon ~1500m of 8-1/2" open hole.

One option is to use sacrificial drillstring, which will be cemented in place and release using Halliburton BHKA tool in order to save rig time instead of placing multiple balanced plugs. In summary this is disconnect tool that would release sacrificial drillstring below and is activated by a dart similar to SSR dart.  Plan is to run ~1500m of 3-1/2" sacrificial drillpipe below, cement the sacrificial pipe in place and drop the dart with displacement fluid to release from the string once displacement is completed.

The Halliburton BHKA disconnect system is being considered and I would like to know if there has been any experience with this particular system or any other disconnect systems would be preferred.

Well has 30deg inclination at disconnect tool

String configuration will be as:

5-7/8" pipe

disconnect tool (BHKA)

3-1/2" NC38 sacrificial string of 1500m

Has anyone else ever used a disconnect system from sacrificial string for cement job ? How did that work? Any specific issues or lessons learned (such as not being able to disconnect, land the disconnect dart in time, etc.) ?



9 answer(s)
Consultant [retired Shell staff]
Total Posts: 249
Join Date: 02/09/05
In the olden days, we did use sacrificial strings either of aluminium or more frequently GRP  Glassfiber Reinforced Plastic.
Drilling Engineer
Total Posts: 5
Join Date: 29/04/13
We recently (within last 2 months) used a BHKA to abandon a 8-1/2" pilot hole from our semi-sub in the North Sea. We set a 3,100ft plug using 2,600ft of 4-1/2" tubing, job went well no issues running or cementing and BHKA released as planned. We had a torque capable tool but decided not to attempt rotation.

We had already identified the sacrificial tubing string to use and a bigger issue was actually getting the required crossovers from the BHKA to tubing and back to the TT550 drill pipe. We had prime and back up assemblies made up prior to load out to minimise handling at rig site.

The next operation after dropping off was pulling back to shoe to set a kick off plug on a CST. One thing that came up at the rig site was that there was no known experience of dropping a CST through a BHKA workstring adaptor after disconnecting. Drawings showed no ID or shoulder issues and the CST was dropped successfully to act as base for kick off plug.
Total Posts: 24
Join Date: 16/08/10
My apologies if a bit out of touch on this-kinda made sense looking at on Kurdistan quite a few years ago , but seems expanding- but  for my education:  well, just great you have 1500m or 2500 ft of HCs need cement opposite  !!  as per regulations spreading.
Just seems to be me, that no matter what hole size, these will be very atrocious worthless cement jobs,  but just to satisfy regulations ?  or to get round stupid regulations.and save money... or just to be seen to be doing different ?
Project Quality
Total Posts: 102
Join Date: 06/05/09

We used the Smith Int'l / Red Baron "TUBING ABANDONMENT RELEASE TOOL" to great effect on two P&A's in the Middle East.

I believe these are built to order only, but they're good tools, virtually fool proof.

Les Sinclair
Franks International
Total Posts: 2
Join Date: 10/11/15

Blackhawk have developed a drillable version of the Stinger Disconnect Tool. And has been deployed successfully for a major independent operator offshore Mediterranean sea, plug depth 15,000ft.


Permanently abandon 2,500+ ft of 12-1/4" open hole and sidetrack for next casing section


Blackhawk’s Drillable Stinger Disconnect System was run with 5-1/2" fiberglass stinger pipe across the open hole interval.

A custom guide shoe was designed and run to allow the string to be set on bottom and rotated, without packing off, as secondary release option.

Drillable components of the system were disconnected 250 ft below casing shoe.

Cement was pumped behind the disconnect dart to place a second balanced plug 65 ft inside the previous casing shoe.

Successfully kicked off the next open hole section just below the shoe for successful abandonment and sidetrack in single cement pumping operation.


Customer successfully isolated and abandoned the open hole section and sidetracked the well, as planned.

Customer saved 4.5 days of rig time compared to previous campaigns where multiple plugs had to be pumped and tested.

Total Posts: 93
Join Date: 10/04/08
I just wanted to clarify that the P3 Perfect Cement Plug Placement Disconnect Tool has been available since 2014, and whilst we have not supplied 100's there have been zero operational problems reported. See attached interesting track record of a 2500ft disposable stinger job.

Our tool was specifically designed for disposable stinger cement jobs, not hydraulic disconnect tools borrowed from coiled tubing drilling or inflatable packer running.

Our tool has an emergency rupture disc by-pass in case the tubing plugs and circulation cannot be achieved. The primary release mechanism is hydraulic with a drill pipe wiper dart landing on a seat but a contingency drop ball is supplied again if circulation is not possible.

Due to "what if questions" rather than operational issues we are introducing a mechanical back-up release feature to our tool in the event the dart does not land for some reason or pressure cannot be applied, then mechanical action can be used to leave the stinger in the hole.

Our system can be supplied with a drillable or non drillable disconnect sub left in the hole. We can supply Fibre Glass drillable tubing and have recently developed a stronger higher temperature rated alloy tubing to leave in the well but remain drillable.

Be clear, you don't have be a large Service Company to have good equipment and supply a good service.
Documents uploaded by user:
Sudelac P3 Job Well Done No101 Rev0.pdf
Total Posts: 15
Join Date: 01/09/12


We have looked at several tools some time ago and here is the summary of pros and cons of each. Based on analysis HB and TAM tools were recommended. We have not used any yet though.

Halliburton BHKA and TAM Hydraulic Release (HR) Tool

- TAM contingency release (ball drop) and torque rating.
- HAL steel option can rival the TAM rating (tensile & torque); in that case this is not a differentiator.
- Extensive run history (hundred plus)  with details was provide by both HAL & TAM.

Blackhawk - Hydraulic Disconnect Tool
- Run history limited (or 6 runs provided).
- Foam balls note recommended.
- No drillable option was available.

Sudelac P3
- Limited run data available and details.
- No contingency option.
- Limited tensile & torque rating.
Senior Drilling Engineer
Springbok Drilling Ltd
Total Posts: 6
Join Date: 20/02/12
Hi, we used the BHKA sub for P&A of an HPHT well years ago. The sub accidentally disconnected early and we ended up cementing in the drill string leaving the sacrificial
stinger in the uncemented open hole below us. We found afterwards that at the particular hydrostatic pressure and temperature, the spacer and OBM system reacted to form a solid clay plug. This plug was at the lead of the cement job and when the clay plug hit the BHKA sub, it caused it to disconnect. It was so far down thenwell we did not see a pressure spike. Hence we very carefully positioned the cement around the drill pipe and not around the stinger. I hope this is a valuable lesson that you can use. 
Managing Director (
Relentless Pursuit Of Perfection Ltd.
Total Posts: 416
Join Date: 10/01/05
Hi Ruslan

Sudelac also have some great tools, drillable cement stingers and great release systems.  Please check out their website

I hope it helps

Best wishes

Posted by

Ruslan Ponomaryov



Total Posts: 1
Jump to top of the page