The Use of Drilling with Casing to Set a New Standard for Drilling Operations in Argentina

Abstract

Abstract During the last 7 years the number of projects and operators using drilling with casing has increased steadily in both the Vaca Muerta shale play and in the Golfo San Jorge mature projects. The following paper summarizes the evolution of the use of this technology and the benefits it has brought to operations in Argentina. Additionally, as some premature failures occurred, the paper identifies some limitations of the technology and the lessons learned from those failures. Within this paper, detail will be presented for the current use of Drilling with Casing (DWC) technology in shale operations and mature fields in Argentina. A summary the drivers and benefits of the technology along with its limitations will be presented. In particular, the paper will include the analysis of some premature failures with a set of recommendations to minimize the risk of failure. Several operators are using DWC in their operations in unconventionals fields in Vaca Muerta and in mature fields in the Golfo San Jorge Basin. The highest percentage of the strings installed is for surface casing where the main target is to reduce Non-Productive Time (NPT) during drilling. The use of DWC has extended to almost all projects in Vaca Muerta, making it a standard technology for the surface casing section in one of the most important shale plays outside of North America. In the Golfo San Jorge basin, the DWC technology has been used to overcome drilling challenges of mature fields with extensive water flooding, wellbore instability, inflow control and differential sticking. The results have helped operators to reduce NPT. The technology has proven its reliability with more than 1200 strings installed in the last 7 seven years. However, some premature failures have occurred and resulted in an intensive investigation by the casing manufacturer. The failure analysis showed that fatigue was the most common mode of most of these failures. The challenge rose when the available fatigue modes could not predict or replicate the failures. Within the paper we detail the probable sources of loads that provoked the failures and some recommendations that will help to minimize the risks for the future. The use of DWC and its benefits in Argentina could be replicated elsewhere reducing costs and improving efficiency. The set of reccomendations of the paper could help to reduce the risk of future operations.