New Low ECD OCIEF (Organophilic Clay-Free Inverted Emulsion Fluid) Weighted with Manganese Tetroxide Showed Superior Performance in Different Fields: Success Story of Drilling with Ocief in High Overbalance Environment Without Downhole Problems, Stuck Pipe Events and Non-Productive Time

Abstract

This paper describes the success of using a new low ECD OCIEF in different Gas Reservoirs at elevated temperatures and with differential pressures up to 4,500 psi. The objective of the paper is to highlight the superior performance of OCIEF during the execution which led in overcoming challenges in such type of environment without compromising performance This paper describes several applications where the OCIEF has been deployed achieving optimum drilling performance while minimizing the formation damage of the reservoir. Consequent applications showed how the implementation of work methods, best practices and optimized drilling parameters allowed to successfully drill the section without downhole problems and pass the Production Screen Test (PST) and finally allow a proper clean-up while producing the well. Initial deployment of the fluid system shows the required fluid specifications to properly address the slim hole challenges in high overbalance environment. Field implementation and continuous fluid performance improvements are reported in this paper, showing how the fluid system helped to successfully complete numerous wells in different fields. The versatility of the fluid system in terms of rheological profile and thermal stability and the minimized formation damage characteristics made the OCIEF as the sole non- aqueous fluid solution applied in Gas Reservoirs under extreme overbalance conditions. No more non- productive time has been experienced over the entire drilling campaign performed with OCIEF. The new low ECD OCIEF (Organophilic Clay Free Inverted Emulsion Fluid) designed a new and enhanced polymer package, without organophilic clay and lignite and with acid soluble manganese tetroxide as weighting agent replaced the usage of water-based fluids without compromising production and with improved performance in extremely challenging gas wells. The proven performance is opening more boundaries for future applications in similar wells.