Agile Response Aimed at Unprecedented Situation of Truncated Gas Demand Via Holistic Network Modelling of Complex Integrated Facilities for Value Maximization
Authors: Kulkarni Sukrut Shridhar 
Published: March 2021

This paper highlights the efforts to mitigate the unprecedented situation of truncated gas demand via network modeling development and harmoniously harvesting value generation by its implementation. Global Pandemic in year 2020 resulted into unique situation of steep truncated gas demand due to economic slowdown worldwide. Hence as a prudent operator its deemed necessary to pursue strategic ideas and innovative concepts to manage offshore complex gas network to handle reduced supply demand balance, whilst protecting fulfill technical and contractual obligations also by optimizing value generation. It therefore demands the development and implementation of robust integrated system (end to end value chain system for hydrocarbon molecule) that would be leveraged on for agile response for deploying appropriate resolution considering dynamics of supply/demand balance and system equilibrium. This study focuses on a state of art that was commenced to develop an End to End Holistic Network Model from well head (fields) to product delivery terminal to scrutinize the complex offshore facilities to decipher appropriate pain points in terms of capabilities, risks, uncertainty, opportunity and exposures by performing robust analysis for trouble shooting, root cause analysis, gap analysis and expansion strategies for required scenario(s).

A novel approach was influenced to create simulation model for complex network with building components i.e. source (100+ fields), sinks (multiple terminals), connectors (120+ export pipelines and ∼8 gas highways) along with pressure boosters (pump/compressor) etc. embedded in model. Major hubs, sub-hub, spill-over pipelines/loop lines including main gas transporting facilities with dedicated receiving terminal which formed integral part of network were also modeled in single platform. Flow co-relations for hydraulic estimations and material balance calculations along with engineering thermodynamics formulae for seamless data transfer in collaboration with operations were inbuilt for representative and resilient results. Simulation model was further validated with actual plant data as history matching and that precise forecasting analysis output. Multiple scenarios utilizing system ullage/ pipeline hydraulics (adhering to first principles) were studied and suitable alteration in operating philosophy e.g. were proposed to cater the truncated demand and to shape development strategies for future portfolios. Multi-level diagnostic was conducted to assure that system parameters such as operating pressure, velocity limits and required quality specifications are within operating envelope for the entire landscape.

Lookahead analysis (what-if scenarios) were performed to evaluate to root cause analysis and troubleshoot at various intensities of the network to cater for equilibrium balance. Multiple contemplating scenarios were accomplished to analyze complex network parameters such as ullage opportunity, pressure variations, hydraulic fluxes, potential choking of low-pressure wells/fields & prospective blending specifications with variations in the supply/demand outlook. Gap analysis was executed in addition to arrive at necessary alterations for operating philosophy, partial segregation of system for pressure balancing due to low flow volume and product quality adherence. Model output assisted to gauge the potential for operating network by implementing appropriate reforms to optimize truncated flow in system and ensuring system is above its minimum turndown rate flow regime and could also propose to have the necessary mitigations to be in place for vigorous liquid management system due to low flow in network.

Above methodology describes how by developing an end to end network model that summarize the granularity of a complex offshore network has facilitated to steer the agile response for operating envelope to cater the fluctuations in the demand/supply balance and optimize offshore allocations by network balancing for value maximization and to form a vision of portfolio strategy for future developments.