Improve borehole quality and wireline running speeds
While drilling a multiwell campaign in Eden Yuturi field, East basin, Ecuador, Petroamazonas sought to improve borehole quality to enable more efficient wireline formation evaluation runs. Drilled from multiple well pads, the directional profiles include J- and S-style wells that reach TD with an 8 1/2-in production section that is 1,000–1,500 ft in length. The wells were drilled initially in the Tena formation, which was composed by claystone interval, and then into the Napo formation, a heterogeneous sequence with an unconfined compressive strength (UCS) ranging from 5,000–15,000 psi and high UCS spike, and where shale, limestone, and sandstone were encountered. To maintain borehole quality in the shale sections, flow rates and hydraulic horsepower (HSI) were controlled.
In offset wells, the operator achieved an ROP of 60–65 ft/h, and the bits reached TD in good condition. The varying formations in the 8 1/2-in section tend to break away and ledge, causing challenges with the formation evaluation wireline runs through the production section. After drilling, time-consuming wiper trips conditioned the borehole to improve wireline running speeds.