The Sticking of a Drilling BHA and subsequent loss of tools, hole footage and hence potentially jeopardizing well objectives; is THE most costly unplanned drilling event that can occur to an Operator. It tops the table of costly NPT events ahead of items such as Well Control incidents, " waiting on weather", lost circulation, equipment failures and rig associated problems. The cost to the industry is estimated at several billions $USD per year. This is probably conservative and in the Gulf of Mexico alone in 2007, it was predicted to be 3% of the total spend on upstream oilfield equipment and services or $7.8 Billion (Dodson et al)1. This can significantly affect drilling budgets where technical and operational risk must be balanced with potential return on Investment (ROI). The technological advance into extreme hostile territory, deepwater and HPHT, makes the investment and risk higher to the extent that some wells are left undeveloped. Deepwater wells are often incurring spread dayrates for services including the rig of $1M USD per day.

Stuck pipe is a reality and the success of a recovery plan depends on a number of issues of which the most important is the efficient separation of the drillstring at the most beneficial point. Current separation technology is the same as it has been since the start of this industry albeit more advanced in its efficiency. Explosives or chemical cutting are still the only methods to separate the drillstring usually requiring mobilization of specialist equipment and personnel.

This paper discusses the application and development of an integral circulation and disconnect tool. Additional to receiving downlinks to adjust a multi position circulating valve, it processes sensory information to establish the status, " stuck" or " free" and ultimately receives a command to disconnect from the BHA or wherever it is positioned in the string. The disconnect is effected by electro / mechanical means and represents a step change in application of technology for this purpose; removing any form of surface intervention or the requirement for 3rd party specialist equipment or personnel, leaving the Operator in control of the event.

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