Challenges in Execution of Brownfield Projects Without Production Shutdown – Case Study
Authors: Meena Rajesh Kumar , Subramanian Senthilkumar , Mudu Balu , Singh Harendra , Kamal Faris Ragheb , Takieddine Oussama 
Published: November 2020

Abstract
Oil producing companies are targeting minimal modifications to existing facilities in an attempt to increase oil production with minimal capital investment and squeezed schedule, thereby maximizing overall return on investment. Such brownfield works impose numerous execution challenges which are dependent on availability of shutdown window. This paper focuses on challenges involved in brownfield tie-in execution and presents mitigation strategies for performing tie-ins without production shutdown based on recent projects executed by NPCC.
Brownfield projects execution has various constraints due to limitations in design modification of existing facilities. Such limitations pertain to existing Facility Layout, Flare System, equipment and adaptation of new standards to existing facilities and various other design /safety compliance requirements etc.
During execution of modification works, early tie-in and shutdown requirements are firmed-up in accordance with the Oil Producing Company's business targets and alignment with all stakeholders. Production shutdown is highly undesirable since it leads to revenue losses as well as schedule and cost implication on the project. Hence, brownfield tie-in strategies always aim to keep production shutdown minimal.
In order to accomplish timely tie-in execution, it is necessary to freeze the Tie-in Execution Philosophy at an early stage of the design in compliance with the producing company's HSE standards. This can be achieved by resolving all brownfield related challenges specially ensuring the early alignment of all stakeholders regarding the requirement of early tie-in, plant shutdown and low production window and by conducting an early site assessment to ensure that As-built drawings are corresponding to actual site conditions.
In one of the Brownfield EPC projects executed by NPCC, various operational mitigation strategies were considered for tie-in execution without shutdown such as providing a temporary flare relief arrangement during Flare Tie-ins, lowering operating pressure to safe limit during execution of Tie-in on Production Oil manifold with single isolation valve, Isolating Produced water system during low production window and continue production with reduced rate by functioning HP/MP Separator in two phase mode during Produced Water Tie-in, lining up an alternative uninterrupted fuel gas header / source during Fuel Gas Tie-in etc. Such strategic methods resulted in execution of all brownfield tie-ins without any production shutdown, thereby avoiding production loss during modification works in an existing facility.
Based on extensive experience with execution of brownfield projects, NPCC is better placed in formulation of tie-in strategies that are aimed at avoiding production loss. This paper presents valuable suggestions and mitigation strategies from recent projects executed by NPCC that will serve as Tie-in execution philosophy for operating companies as well as Contractor companies in petroleum industry. These strategies will assist companies’ in effectively optimizing their resources, enhancing the efficiency and profitability of their projects.