Enhancing Plug-N-Perf Technology for Unconventional Wells

Abstract Company has been implementing fracturing in its carbonate reservoirs since 2017, with the aim of improving well performance, reducing operational costs and risks, optimizing reservoir management. This paper reviews challenges faced and evolution of Plug-and-Perf (PnP) multistage fracturing technology implementation in Company through engineering, field execution and lessons learnt, with special focus on milling of frac plugs and surface flowback set up and operational methods to face and efficiently handle harsh high temperature high pressure (HTHP) and high H2S environment. Methodology approach is a flexible and iterative method that allows for rapid adaptation and improvement of PnP operations. Methods involved conducting several simultaneous PnP operations with different service providers and vendors, and capturing and implementing lessons learned and best practices across all operations. Main steps for the methodology included the following: operational optimization, equipment selection and engineering, whereby engineering process of designing and implementing PnP technology based on operational optimization and equipment selection results throughout all the process. Paper describes and shares experience and lessons learnt for surface equipment set up to run and set plugs and casing perforation, lessons for plug removal from horizontal sections via implementation of thorough engineering process, utilization of latest available technologies, such as extended reach tools, composite and dissolvable plugs, utilization of properly planned and designed surface flowback equipment to handle HTHP operations with H2S content in fluids returning to surface during milling operations. Optimizations and improvements include, but not limited to: thorough engineering and selection of coiled tubing (CT) pipe size, milling bottom hole assembly (BHA) components, surface flowback equipment selection, milling and wellbore clean up practices and recommendations Approaches, lessons learnt and best practices that are described in the paper will be beneficial and can be used as a reference source for other projects for PnP operations where harsh HTHP and H2S environment present, Company will continue to implement and optimize PnP technology in its carbonate reservoirs, as well as explore the potential and feasibility of PnP technology in other reservoir types and environments.