Drilling and completing oil and gas Wells into the unconventional Vaca Muerta Formation (Fm.) has proven to be a challenging task since the beginning of the development.
The unique characteristics of the several formations oil operators must drill through in order to reach Vaca Muerta Fm along with the extended reach horizontal sections, make the complexity of the drilling operation to become a constant challenge for an optimized well architecture. To add up the extensive and demanding completions program, currently being executed with an average of 60 frac stages per well with a work pressure up to 13500 psi, make the construction of wells to be an even more challenging task.
One of the main factors that make the previously describe scenario into an even more complex is the presence of Sustained Annular Pressure (SAP), this phenomenon affects around 35% of worldwide oil and gas wells (Farag, Mahmoud - 2015). This challenge represents several risks such as contamination of water formations, emission of greenhouse gasses, potential well blow outs.
This situation it's been witnessed in some of the recently drilled well in the Vaca Muerta Fm, turning SAP into one of the challenges oil operators face today. Said phenomenon has been evidenced by the presence of pressure in the annular spaces at surface once the hydraulic fracturing programs have been completed.
To mitigate SAP several alternatives to enhance or replaced the traditional cement seal are being evaluated; mechanical integrity of the cemented seal can be affected by the stresses generated in the casing as the frac operations gets developed, suffering multiple compression and expansion cycles.
An effective and proven solution, that can be integrated into the well's completion program helping to achieve the prevention of SAP, is the Metal Expandable Packer (MEP) technology. This new technology can help mitigate SAP eliminating the need for complex remedial operations that usually increases the costs and operational risks.
The following paper shows the process of technology selection, qualification, job planning, field deployment of MEP and results.
