A new well logging/perforating challenge arose from a Highly Slanted (HS) exploratory well that was drilled in Colombia. This HS, exploration well (up to 75 degrees inclination) was drilled in the “Llanos Area” to 18,040 ft MD. Available logging and perforating technologies were reviewed and evaluated which included Drill Pipe, Coiled Tubing and e-line options. Tubing Conveyed Perforating (TCP), using a combination of Drill Pipe (DP) / tubing string and Coiled Tubing (CT) perforating technologies was considered as part of the evaluation, but the selected method was an e-line well tractor to deploy the logging tool and perforating assembly. Using tractor conveyance saved significant time and associated rig costs with respect to pipe conveyance to perforate this new well. In so doing it also set two, Latin American, regional records for tractor-conveyed tools in one well.
Based on site-specific experience, the operator concluded that each well intervention with drill pipe would require 48 hours per trip. In August 2011, after a formal risk analysis and systems integration testing (SIT), the operator mobilized a down-hole, robotics-solutions provider and successfully tractored a cement evaluation log to 11,079 ft. A regional record was set for longest tractor-conveyance during the first perforating run of 12,095 ft. A second perforating run of 11,037 ft was successful and set a regional record for longest, cumulative, tractor-conveyed distance in a single well at 34,211 ft. The cement evaluation and perforating runs were completed in less than 40 hours versus more than 96 hours, which was the estimate with pipe conveyance. The results of operations in the HS Llanos well are presented. Lessons learnt from these operations are part of this study.