In the SAGD industry, it has become more common for operators to drill into active or pre-heated oil- sands zones. These hot zones provide for a challenging environment to drill a single well, let alone use electronics for active ranging technology for accurate wellbore placement.
This paper will discuss the intent of a new head tension-compression device and the process leading from extending conventional thinking into using it as a solution for a challenging wellbore environment. Through a case story, the challenges proposed by a client in Western Canada will be examined, as will the lessons learned from the unconventional solution.
When drilling SAGD well pairs, it is common practice to have an active ranging device placed in the “target” wellbore to aid in accurate well placement. The active ranging devices are electronic in nature and are limited to temperature exposure for reliable performance. Collaborating with the operator, a secondary measurement provided by an e-line device was used in conjunction with field proven magnetic ranging equipment in order to provide real-time feedback to surface with the purpose of mitigating risks due to the high temperatures. The diagnostic device was used to monitor the effects of pumping fluid into the wellbore in order to cool sufficiently and thus protect the sensitive electronics in the active ranging device.
The case story presented in this paper will discuss the adaptation of an existing head tension- compression sub to work in conjunction with active ranging technology, providing real-time readings to surface. These real-time readings not only measure the tension and compression of the downhole toolstring but also temperature.
To date, this system has been used in a number of operations for operators in Western Canada in active thermal zones. Operations have successfully monitored the temperature real-time for the protection of the downhole devices in addition to evaluating the cooling methods of pumping fluids from surface.
This system now enables operators to consider further e-line interventions in wellbores with high risk of exposure by providing real time diagnostic data to allow for better decision making at surface, which will reduce risk of failure. For many operators drilling in pre-heated oil-sands formations this has proven a cost effective and desired system.
The use of this diagnostic sub is now a proven solution to place in the target well in conjunction with active ranging technology.