Margarita 10: Drilling Strategy of the Fastest Well in the Bolivian Sub-Andean Region

Abstract

Abstract Repsol completed a 10-year long drilling campaign in the sub-Andean region of Bolivia the first semester of 2021 with the Margarita 10 infield well, a drilling campaign where some of the most prolific gas producers in south America were drilled. The complexity of these gas projects is well known and includes great geological uncertainty, hard rock from surface to bottom, high pressure and high temperature conditions among others. Margarita 10 was the last well of the above-mentioned campaign and served to prove that when you combine proper planning with great execution practices, fit-for-purpose technology and artificial intelligence there is no benchmark that cannot be improved, even if it's drilled in the middle of a worldwide pandemic that greatly affected the oil and gas industry and life in general. This paper will explain how the Margarita 10 was drilled and completed in little over six months when the standard for this type of wells was a year plus, the planning process and all the adjustments made to ensure it was a success even when all the odds were against it. The technology used and the engineering decisions behind it, the learning curve and the lessons learned from the vast experience the operator has in these fields which greatly helped managing the geological uncertainties that come with this type of plays. Among the technologies discussed we have a 3000 HP rig specifically assembled for this project, robust downhole tools to withstand huge loads, state of the art drilling bits with novel PDC cutters design, premium casing connection, liner and wellbore isolation technology. Special mention is made to Inwell.AI, the in-house developed, Repsol proprietary artificial intelligence tool that allowed the drilling team to reach rates of penetration never reached before in this kind of formations and the longest runs in the Bolivian sub-Andean region. The Margarita 10 project proved that efficient drilling operations can be achieved even in the most uncertain of environments, reducing historical time and cost estimations in more than half while accomplishing all proposed targets. Margarita 10, besides being an operational success, became one of the biggest gas producers in the country and showed that when things are done right there is no limit to what can be achieved in this industry.