Stuck pipe is the Drillers nightmare that stalks and haunts most drilling campaigns. Sticking a drilling BHA and subsequent loss of tools, hole footage and potentially jeopardizing well objectives, is THE costliest unplanned drilling event that can occur to an Operator. It still tops the table of costly NPT events ahead of items such as Well Control incidents, waiting on weather (WOW), lost circulation, equipment failures and rig associated problems. The cost to the industry is estimated at several billions $USD per year.
Over the past 30 years, wells have become more advanced and ambitious and as a result stuck pipe and hole problems have become more prevalent. The root cause of most stuck pipe incidents is Poor Hole Cleaning. This is the root cause for more than half of all incidents world wide.
In 2008, Gordon Hunter, an experienced Drilling Manager having spent his career with Shell, BP, Total and a host of other Operators as a consultant, decided to work on a solution to this perennial problem. He teamed up with Cutting & Wear, the renowned engineering company based in Sheffield in the UK, and together they formed a company: Intelligent Drilling Tools (IDT). The remit was to develop intelligent downhole tools that would directly tackle the issues of poor Hole Cleaning and Stuck drilling tools.
IDT has focussed on designing an Intelligent Circulate and Disconnect tool, iDisc?, that provides a solution for hole cleaning management and reliable outcome in a stuck pipe situation without the need for 3rd parties and protracted surface intervention. Having this capability in the Drillstring at all times will save cost through efficient hole cleaning and less reliance on conventional drilling support methods (wireline/explosives/chemicals) providing an instant and controlled solution in vertical, highly deviated and horizontal wells. Please review the iDisc? features through the menu above.
How does it Work?
iDisc has the unique ability to realise if it is stuck. It does this by sensing its environment through accelerometers, pressure sensors and compression / proximity sensors. The data is fed into its onboard computer and the tool moves into various modes depending upon inputs. Please see the iDisc? Process Chart which graphically demonstrates the various modes including the process to disconnect. The data in this chart is taken from a real stuck pipe situation with the iDisc modes and reactions interpreted into the chart. In other words, this is how iDisc? would react to that data. Data from “Countdown” and actual “disconnect” data on the chart is inserted by us to demonstrate how a Disconnect would actually take place.
Features
1.Multiple position circulating valve
2.No surface intervention via drop balls
3.Strong mechanical design in terms of drive splines (proven technology) and segmented clutch (easy to understand and obvious strength)
4.Interlocked mechanical, electrical and software safety systems to control the disconnect
5.Duplicated trigger mechanisms. 100% redundancy
6.Modular electronics assemblies with sensor redundancy
7.Systems check for trigger mechanism and electronics
8.Reliable and robust
9.Full bore
10.Onboard intelligence requires no activation from surface
11.Low power consumption. Long battery life
12.Minimal maintenance
13.Surface box to provide tool status and guide Driller through disconnect process
Benefits
1.Circ sub delivers improved hole cleaning while drilling, quick clean up at section TD and high concentration LCM dump bypassing the BHA.Circ sub
2.Downlink to open circ valve into multiple positions. No drop balls. Full throughbore
3.Allows a controlled disconnect in any well regardless of well design
4.Customer can choose to disconnect in response to the best economic scenario
5.Disconnect can be effected by the drill crew without the need for specialist service personnel
6.No surface equipment required
7.Disconnect can be aborted at any time during the process
8.Disconnected tool leaves a specific profile to fish on if required
9.Multiple tools with different programmes can be run in the string to allow disconnects in various positions
10.Removes elements of risk when considering ambitious well design
Why run iDisc
1.Running iDisc in your BHA gives you control over potential stuck pipe scenarios. Hopefully it won’t happen and maybe you will get free but in todays cost environment……hopefully and maybe are two words you don’t want to be using in the context of your operation. Run an iDisc in your BHA and/or in the HWDP. You can set them with different parameters so they know which one you are speaking to. They have onboard intelligence and will realise when the BHA is stuck. All you have to do is follow the process and send the final signal relating to whichever iDisc you want to trigger. See the iDisc Process Chart which graphically shows the whole process from start to finish.
2.Highly deviated and horizontal wells preclude the use of Wireline unless dragged by a tractor. By running iDisc, you have the capability to disconnect at any angle at any depth.
3.Save cost. By running an iDisc you will not be waiting on wireline crews or be logistically constrained. Disconnection is at your discretion. Don’t be constrained by Dangerous Goods carriage i.e shipping chemical cutters etc. If you are running all MWD/LWD tools either in your development or exploration well, the only reason to have that Wireline unit and toolhouse is for Drilling Support. Running an iDisc? gives you all the drilling support you need. A controlled disconnect at your discretion and a clean fishing profile to latch back onto with your heavy jarring BHA.
4.Safety. Run an iDisc and you will not have to perform any hazardous procedures involving working down left hand torque to assist an explosive back off.
Q & A
Does it work in ALL wells?
Yes. Vertical, inclined, horizontal, ERD, HTHP, it does not matter.
How does it work?
Sensors feed an onboard processor that determines through a logic sequence, that the tool is stuck. There are several conditions that must be satisfied before the tool puts itself into disconnect mode. The operator then gives the tool the confirmation signal to disconnect.
The tool then starts a countdown to disconnect which the Operator can abort at any time. The length of countdown can be customized by the operator. Once the countdown has concluded, the tool waits for the final confirmation to disconnect. When it receives the signal, a rugged electromechanical system fires the trigger mechanism.
How do I know it will not premature disconnect?
There are several safeguards to prevent an unintentional disconnect. There is a simple mechanical safety interlock which must be defeated before the clutch can operate and power is supplied to the electric motors.
Power will only be available once the onboard sensors and software have decided the tool is stuck. The tool is “failsafe” and should it detect an anomaly with any of the sensors it will not go into disconnect mode. All sensors and electronics are duplicated. There is a logic sequence which must be met before the tool will go into disconnect mode.
This logic takes into account all events such as tripping, drilling, circulating, stationary modes such as slipping and cutting at the shoe etc. The final signal to disconnect is given manually by the Operator. If the tool is not in Disconnect mode, it cannot physically disconnect.
How do I know its working?
There is a tool Healthcheck that is easily conducted prior to running in the hole.
How strong is it?
iDisc separates torque and tension/compression forces. It is as strong as a Drillpipe tooljoint.
How reliable is it?
All electronic components are military spec and are tested to high temperatures to meet downhole conditions. Completed tools are shock and vibe tested to industry standards. Tools have a service life indicated during the surface healthcheck.
Do I need a surface Operator?
No. It is intended that the tool is operated by either the Directional Driller or Company Drilling Supervisor. Full instructions are provided and an electronic Surface Box is optional. The Surface Box can be programmed with the spec of the downhole tools and guide the Operator through the Disconnect process.
What sizes does iDisc come in?
The tool will be available in nominal 8″ and 6″ sizes.
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