Operators in the Neuquén basin have developed Vaca Muerta with different results. In our case, it has gone from vertical exploratory wells, almost ten years ago, to a current development phase with multi-horizontal well PADs targeting different landings. During this period, many lessons have been learned and applied. This paper explains how we have become more efficient and cost effective by increasing production and reducing well delivery cycle time, while fostering the long-term sustainability of the project by reducing the environmental impact of operations.

The implementation of different surveying technologies (ranging from initial vertical wells with simple and specialized logs, cores, XRD, proppant tracers and micro seismic interpretation, to multi-landing horizontal stimulated wells with more complex techniques such as 4D seismic, chemical tracers and fiber-optics studies) has guided the evolution of completion design, shifting stimulation jobs towards larger, more complex and more resource consuming scenarios.

In this regard, together with the increasing lateral length of the wells, operations have shifted towards technologies that foster time maximization in a cost-effective manner. Water transfer and sand logistics have been reformulated to a new scale. Also plug and perf, coiled tubing and fracturing jobs have boosted performance and reliability through the implementation of new technologies and optimization of the operations sequence.

Different field tests and studies have driven changes in completion design to maximize production at lower costs. Some fracture parameters evaluated have shown a positive impact on production. Product QC (e.g., proppant and fluids tests) and service reliability improvements have shown to be key to achieve completion objectives in a timely manner. Great efforts have been made to break paradigms regarding water and sand logistics. Only the combination of all these factors, coupled with the implementation of state-of-the-art technologies, can create a synergy that promotes the sustainable development of unconventional resources.

Over the last years, several studies and field tests have shifted the way of conceiving best stimulation practices for unconventional wells. This document describes how the increasingly demanding requirements of completion design were caught up by operations. The historical evolution described in this work shows both positive and negative experiences. Finally, we examine a possible stimulation strategy path for the challenging context that shale developments shall face.

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