New Compact Series Tractor and Stroker / Tractor Technology Delivers Smart, High Performance Intervention Capabilities and Efficiencies to Restricted Rig Up Height Electric Line Operations
Authors: Murchie Stuart William , Tinnen Baard , Mclnally Gerald , Motland Arne 
Published: March 2023

Wellsites, in particular those offshore, often have limited mast or A-frame height availability for the rig-up and deployment of tools into and out of the well. This can often lead to limited choices in, or compromises to the technologies being deployed, or the efficiency in which a service can be executed. The challenge is more acute when deploying electric line tools in highly deviated or horizontal wellbores, where a tractor is required as part of the toolstring configuration for conveyance purposes.

Recent developments in electric line deployed tractor and powered mechanical intervention technologies have been significant, implementing a platform architecture to the design and construction of the tools and leveraging digitalization for enhanced in-well visibility, agility and dynamic control. This in turn has delivered improved component modularity and sharing, multifunctional integration, power management and ultimately the performance, efficiency and capability of the toolstring, be that of the tractor itself or when integrated with an additional powered mechanical tool such as a linear actuator or rotational device. A compact series of these tools has now brought these advancements to toolstrings specifically developed to address and optimize deployment on wellsites having limited or restricted rig-up height, offering string length reductions of 33% for the Tractor and 45% for the integrated Stroker/Tractor combination.

The intervention operations presented in this paper were to be executed as rigless operations, with the required lubricators and pressure control equipment positioned on the BOP deck of the platform. This presented a rig-up height limitation as low as 12.33 meters on one wellsite. Furthermore, some of the wells were deviated, e.g. 81° on one, 70° on the other, necessitating a Tractor in the toolstrings – a definite requirement or as a contingency. The first operation was multi-run, to deploy a plug, a mechanical tubing cutter, and finally a ballistic tubing puncher. Here, a compact Tractor was incorporated and activated on all three runs, conveying the toolstrings to task depth. The second operation was to pull a deep-set plug. Here, a compact Stroker/Tractor was incorporated. While the plug depth was reached and the stroker engaged without having to activate the Tractor, the string did hang up when coming out of the hole with the plug, this attributed to swelling of the plug element. To recover, the tractor was activated and used to push the stroker and plug a short distance down the well, following which it was deactivated and the string with plug successfully pulled out of the hole. The third operation incorporated straddle deployment and assembly as part of a leak detection and rectification sequence. This required several runs, deploying/assembling, and retrieving the straddle. The fourth operation was a multi run perforation deployment in a deviated well, carried out in a confined space between the hatch deck and pipe/weather deck of the platform. The compact length of the tractor not only enabled the operation to be carried out, but its short length made for fewer runs to execute the full perforation interval required, delivering time saving and risk reduction to the operation.

All operations were completed without compromise to the functionality of the tractor or stroker, nor to the passenger tools being deployed and hence the tasks being undertaken. In three of these operations, the scope could not have been completed without the availability and application of this compact conveyance intervention technology.