A World Record Set for Wireline Intervention by Conveying PLT BHA Beyond 40,000 ft MD With Composite Carbon Rod and High Powered Tractor Conveyance in Extended Reach Wells With Complex Trajectories
Authors: Correa Gladwin , Alyan Mohand , Nasr Karim , Zakaria Mahmood , Troup Duncan , Murchie Stuart 
Published: October 2023

Intervention operation in extreme extended reach wells using conventional technology is extremely challenging and quite often accessibility is limited. The inability to access these wells restricts the operators to drill and complete MRC wells. This paper intends to describe how the physical properties inherent in carbon composite materials provide a means of deploying logging tools into such a well in combination with a high-performance tractor, and to document a case study where a total depth of 40,600 ft.MD was achieved in flowing condition.

Extending well accessibility in horizontal well by electrical tractor has been done for a while however the cable friction and cable rating are limitation factors. The medium for the conveyance becomes the critical component of the system to both maximize the ultimate depth achievable and to ensure safe retrieval. Low friction, low weight and high strength of the rod all combine to reduce required tractor loading and ensure safe recovery. The rod rigidity confers exceptional depth accuracy and removes the potential of tool-lift at high production rates, allowing logging under conditions that are truly representative of commercial well operation.

A well drilled to a depth more than 40,000 ft. measured depth, with a trajectory designed to maximise the contact between wellbore and reservoir, completed with a limited entry liner. A total of 37 compartments with lengths between 700 ft and 900 ft separated with swell packer assemblies along a horizontal section of ~27,487 ft. Critical information about the production flow, including toe/heel balance, had been unavailable because of the limitations imposed by the available intervention methods.

The intervention was designed to fully exploit the physical properties of the carbon composite rod in combination with the most efficient in-well controlled tractoring technology available and aimed to reach deeper than 40,000 ft MD. Simulations based on previous experience showed that this depth would be achievable with the tractor chosen and further that this could be achieved even with the well flowing at rates of over 50% well capacity. This meant that deferred production could be minimised along with waiting periods for flow stabilisation.

The intervention was successfully concluded in a single operation, gathering production data from as deep as 40,600 ft MD. Both rod and tractor performed as per planning simulations with significant margin, indicating further performance enhancements in reach being readily achievable.

Successfully reaching the toe section of an extreme extended reach well and consequently proving the accuracy of the prediction models for both rod and tractor performance demonstrates the ability to gather production data from previously unreachable areas of high value wells. For intervention engineers, precise planning becomes possible in even the longest of extended reach assets.

Technologies like carbon composite rod and high-performance tractors enable the operator to access long horizontal wells and perform well services effectively to maintain the life cycle which is inaccessible with conventional solutions. The enhance accessibility also enables operators to drill long horizontal wells from environmental island by reducing well counts and accelerating development to increase oil recovery from areas that are currently unreachable from existing islands and wellhead platforms.