Abstract

The Fortín de Piedra block is located in the central part of the Neuquén Basin with a surface area of 248 km² (61,282 acres) that is evenly distributed within the wet gas and dry gas windows.

The successful exploratory and appraisal stages in the central and northeastern sectors of the block, consisting of two vertical and five horizontal wells targeting the same landing zone, rapidly led to a massive pilot/development program. This ongoing phase, involving six drilling rigs and two completion sets, has resulted in an outstanding production increase of ∼14 million m³/d (∼500 MMCF/d) in an 21-month span starting in February 2017. Development activity is currently focused on proved zones while exploratory vertical and appraisal horizontal wells are being drilled to de-risk the remaining areas of the block. With 59 wells on production and a total of 81 horizontal wells drilled, Fortín de Piedra block has become one of the most important Vaca Muerta projects in the basin.

In this block, the Vaca Muerta Formation is located in a central to proximal basin setting with a total thickness ranging between 300 and 480 m (∼984 to 1575 ft), decreasing to the southeast. Its upper limit is correlated to the T5 surface in the northwest part of the block and approximately with the T4 surface toward the southeast.

The initial navigation bench corresponds to bottomset facies of Unit 2 (”Orgánico“) and was selected based on total organic carbon, total porosity, and geomechanical parameters established from log response.

Initial well spacing was defined based on analogous U.S. shale plays and results of numerical simulation models. To confirm spacing strategy, comprehensive studies are being performed including microseismic, water and gas tracers, interference tests, and frac-hits monitoring.

Tecpetrol’s strategy also includes the evaluation of Unit 1 (“Cocina”) of the Vaca Muerta with several horizontal wells that, in case of success, would trigger a potential staggered development between lower Unit 2 and Unit 1. Moreover, the upper Unit 2 shows several intervals with high potential for future evaluation.

The foundation for the outstanding results was the proper characterization of the key geological drivers achieved due to the comprehensive evaluation of the data acquired during the early stages, benchmarking, and inherited know-how from U.S. shale plays, as well as the experience gained in the basin by other operators. All this was complemented with a detailed planning and execution of the different stages of the project. Currently, Tecpetrol’s main focus is on development optimization by understanding key production drivers and improving operational efficiency.