Summary
The development of Vaca Muerta basin, in Loma Campana Field of Neuquen, Argentina, started in 2011. Currently, there are more than 335 wells on production. Wells are drilled and completed from multi-well pad locations of 4, 6, and 8 wells and though the primary approach is exploitation from mostly deviated wells, it is shifting to more horizontals in selected areas of the field.
Oil produced from Vaca Muerta Formation is light (35-55° API) and volatile with a bubble point pressure of approximately 2800psi. Variations in oil density and GOR are observed across the field. Original reservoir pressure is approximately 8500 psi.
From an operational perspective, the field has presented a unique set of challenges and peculiarities. Initially and throughout the first year, flowing wells are restricted by the use of surface chokes to manage drawdown and safeguard the integrity of induced hydraulic fractures. Later, due to the low rate of recharge from the matrix into the fracture network, wells experience low production volumes and are produced intermittently, resulting in paraffin deposition. Eventually, it is necessary to install artificial lift systems suitable for this type of flow behavior. Variables and operational challenges encountered in the production of the Vaca Muerta formation are described and analyzed as part of a production philosophy designed to minimize problems and optimize production. Preventative downhole methods (mechanical, chemical, and thermal - including insulation and contact heating) are used to help reduce or stop the deposition of paraffin and ensure continuous flow from the wells.
Artificial lift applied in the field includes: sucker rod pumping with pump off controllers, and plunger lift (single or two stages) installed in areas with low GOR despite suggestions that this is not possible in the existing literature. Plunger lift installation has been a great accomplishment for the project with very good production results.
