Obtaining high resolution, quality formation evaluation data is still only possible with wireline logging. However, with the continued push into deeper and more complex drilling environments, many challenges have been placed in the way of wireline logging, including high tension, high deviation, and increased differential pressure. These factors contribute to an increased risk of tool sticking incidents and lost-in-hole scenarios. Several methods of mitigating these issues on surface (powered capstans, pipe conveyance, etc) have been implemented in the past, but none have been successful in reducing or eliminating the risk downhole without introducing further drawbacks. This paper describes how a new wireline conveyance system has eliminated these issues. The conveyance system consists of wheeled carriages that carry the toolstring off-centre. The mass of the toolstring acts as a counterweight to ensure correct tool orientation in the wellbore. This orientation feature also enables a "guide" device to help navigate ledges and washouts. Such a system eliminates toolstring hold ups, allows access to highly deviated wells without pipe conveyance or tractors, and significantly mitigates differential sticking hazards, while also offering additional benefits in operational efficiency and data quality. A case study from a particularly difficult well in New Zealand is presented. Data acquisition in this well was fraught with challenges: In addition to the 2000m tangent section at 67° deviation, well had severe borehole breakouts. Previous experience in similar scenarios with conventional data acquisition methods yeided poor results. The wheeled carriage system was deployed in multiple innovative configurations resulting in the acquisition of excellent quality data from five wireline descents in hole. This wireline conveyance system has been routinely deployed on multiple deepwater operations in the Gulf of Mexico. One such operation is presented where large gains in logging efficiency have been realised, particularly with the elimination of differential sticking risk and time-consuming pipe conveyed logging. The new technology takes a holistic approach to wireline tool conveyance: Prevent sticking issues using wheeled carriages and mitigate fishing risk using ultra-high strength wireline cables. Wheeled carriages greatly reduce the tool-borehole contact area, preventing the incidence of tool sticking. In addition, wheeled carriages reduce drag while ensuring optimum data quality by sensor position and orientation within the wellbore. Ultra-high strength cables provide ability to log at very high tensions and at the same time provide high overpull capability. The result is a safe, efficient, cost effective and complete Wireline data acquisition.

Due to adverse hole conditions, Operators in the Nam Con Son Basin have had difficulties carrying out their wireline logging programs. Unplanned wiper trips and pipe conveyed logging have often been necessary to acquire log data. These remedies are expensive and time consuming and lead to substantial inefficiencies during execution. In search for operational efficiency, a revolutionary conveyance technology was used with the wireline logging tools. The conveyance system consists of wheeled carriages which are secured to the exterior of the logging tool housings and aligned at regularly spaced intervals. The carriages have large diameter wheels with an active bearing lubrication system and carry the tool-string over and above wellbore cuttings. The wheels significantly reduce tool drag, facilitating conventional logging in very high angle wells. The carriwages orientate the logging tool sensors to enhance sample recovery and data quality. The holefinder consists of an upturned nose cone, analogous to a ski tip, which effortlessly slides over ledges without stopping. The intermediate logging operation continued over 5 days, during which 5 runs were made with up to nine carriages and a hole-finder on each tool string. All tool-strings ran seamlessly to TD and logged out smoothly without issues, facilitating excellent data acquisition. Following success in the intermediate hole section, the conveyance system was deployed on all wireline runs in both the main wellbore and sidetrack with similar results. The conveyance devices allowed the drilling and exploration team to achieve all of the pre-drill objectives while eliminating the unplanned costs experienced with previous logging programs. The conveyance system provides a cost effective method for managing high deviation wellbores while enhancing the operator's data acquisition needs for exploration evaluation. By avoiding pipe conveyed logging and wiper trips, 11 days of rig time was saved on a floating rig, with associated cost savings of USD 9.4M. Together, these complimentary devices form a complete conveyance system that uniquely resolve all the challenges that have plagued wireline logging for over 50 years while enhancing data quality. The technology also has applications in well intervention operations.

Drill Pipe conveyance (TLC/PCL) of wireline logging tools or Logging While Drilling (LWD) is usually required for high deviation / high differential sticking risk logging scenarios. These are costly in terms of rig time and service company costs. This paper details how a full suite of high-quality open hole log data was obtained on wireline in a high angle 16,500ft wellbore utilizing a new conveyance system and a polymer-locked high strength cable. The new conveyance system, utilizing wheeled carriages and a holefinder with nose angled upwards, takes a holistic approach to tool conveyance, reducing drag while ensuring both correct tool orientation and optimum contact and standoff for each logging service. Management of tool centers of gravity relative to the wheel axes ensures correct orientation. The reduction in friction due to wheeled carriages vs weight and cable load is modelled before the operation in order to ensure successful runs, both into and out of the wellbore. Polymer-locked high strength cable significantly increases maximum safe pull capability and enhanced data transmission technology allows faster logging speeds, greater rig time efficiency and reduced sticking risk. The wheeled carriage system enabled conventional logging in a high angle well, minimized stick-slip and reduced differential sticking risk. The unique holefinder prevented tool hold up during descent. The Vertical Seismic Profile (VSP) run (the only run not able to utilize the system due to tool size and design) was held up on a ledge above the lowest reservoir of interest. The high strength cable allowed safe retrieval of tools (over-pull > 6000lbs) in one particularly sticky zone. In a world first, an array sonic tool was centralized through management of weighted and eccentralized tool sections using bespoke wheels. This eliminated the drag inherent to traditional methods of sonic centralization (centralization using powered calipers and/or spring centralizers), resulting in excellent data quality. Nuclear Magnetic Resonance logs were obtained by orienting the tool sensor with wheels which utilized tool weight to provide sensor application force. This removed the need for additional centralizers, resulting in data devoid of stick-slip artefacts (an issue in previous wells). The formation fluid sampling run was conveyed on drill pipe, taking 6 days of rig time. There are further significant efficiency gains to be had on future operations by using the new conveyance system on sampling tools (operators have already moved in this direction in the Gulf of Mexico).

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