_ A multidisciplinary engineering approach enabled the construction of a landmark extended-reach well in Brazil, delivering what the companies involved believe to be the longest high-angle openhole section ever drilled in Latin America and the highest extended-reach drilling (ERD) -ratio ever recorded in the country. The operation required advanced survey methodology, precise reservoir navigation, gyro measurements-while-drilling, and real-time engineering support. The result was an optimization of well placement within the reservoir to improve field management, providing a repeatable model for future long-reach wells with shallow total vertical depth (TVD), high-displacement environments. Introduction The oil and gas industry is searching for higher efficiencies in hydrocarbon recovery and reductions in operating costs. This scenario is especially critical in mature fields, which currently represent about 70% of producing assets worldwide and have accumulated more than 25 years of activity. Managing such fields depends on precise well placement within the reservoir. To mitigate lateral and vertical deviations, advanced geosteering techniques have been applied, combining magnetic and gyroscopic sensors with deep resistivity technologies. This integration reduces uncertainties in absolute and relative well position, improves the match between acquired data and the actual structure, and strengthens confidence in reservoir mapping-while-drilling (RMWD). The well presented in this case study was drilled in the Polvo Field, located in block BMC-8, in the southern portion of the Campos Basin, a petroleum province consolidated since the 1970s, with cumulative production exceeding 14 billion BOE. The area operates in a water depth of approximately 100 m and has had a fixed platform since 2007, producing from Albian carbonates of the Quissamã and sandstones of the Carapebus Formation, under depletion, aquifer influx, and injection projects. Even after 4 decades of activity, the region remains relevant in the Brazilian market, accounting for about 20% of national production and presenting significant remaining volume. Under the current operator, Brazil’s PRIO, the field has undergone continuous revitalization campaigns, including drilling, recompletions, and the tieback integration with Tubarão Martelo in 2021. These efforts have extended the field’s economic life and reinforce the strategies used for mature-field development. ERD continues to evolve as operators push the limits of field accessibility, operational efficiency, and enhanced reservoir contact. This well represents a major advancement. It was a technically demanding project that was executed at shallow TVD depth but with extreme measured depth and lateral displacement. The operation required balancing torque and drag, directional complexity, reservoir uncertainty, and rig limitations, conditions that typically constrain well design in the region. The engineering strategy aimed to expand reservoir contact and overcome structural and geomechanical limitations typical of long-reach operations. The project resulted in 5, 362 m of high-angle openhole, establishing a new operational record in Latin America. The well also reached an ERD ratio of 4. 37, the highest documented in the country. This demonstrates the feasibility of executing long sections under shallow TVD and mechanical capacity constraints.
Chicanha et al. (Mon,) studied this question.