A Shift in a Paradigm for Monetization of High CO2 Fields by Leveraging Simulation Modelling Approach for Malaysian Gas Network
Authors: Kulkarni Sukrut Shridhar 
Published: March 2022

High Contaminants fields in Malaysia though forms large part of resource encounter challenges to monetize economically by convectional means that needs higher footprint, complex and heavy structure. Going forward, trending observed is much higher in Carbon dioxide (CO2) (15-40%) for sizeable fields and higher than 40% for some of the prospects. As prudent operator it is imperative to innovate novel methodologies to convert these resources into reserves. Study intent is to develop the asset network into simulation environment, and leverage on modeling to optimize the monetization of these high CO2 fields by multiple approaches such as opportunity to comingle with sweet fields, conceptualization for clustering of sour fields with common CO2 management, to opt for dedicated corridor for the sour gas (high CO2), aligning feed quality as per customer requirements while adhering system obligations.

High CO2 feeders needs to be aligned in a strategic way that meets the technical and commercial contracts. An independent system was designed, developed, and implemented (syndication with portfolio management) to not only predict the resultant compositions but also to cater for system hydraulics, effective envelope and adhering the operational safety. The network model consisting of multiple feeders, export pipelines, gas highways and various terminals were built in thermodynamic environment, implanted with appropriate flow correlations to replicate the situ conditions. It was further validated with Plant Information (data) to minimize the simulation tolerance values. Vendor inputs for rotating equipment were also added for representative outlook at the same time minor details such as fitting, bends were ignored to optimize the simulation run time. Inputs were classified as variable inputs (priority of supply, demand center operation precedence, production profile) and fixed inputs (engineering details). Model developed was comprehensive to account for CO2 specifications along with other compositional hydrocarbons including other contaminants such as Nitrogen(N2), Hydrogen sulphide (H2S).

Multilevel diagnostics could be achieved to generate heat maps as per CO2 concentration across various sections of the network. Modeling could decipher the opportunity to recognize sweet and sour concentrations at various sections of the network along with potential risk to the downstream. Strategies could be planned to evacuate high CO2 fields at intended customer that could handle these CO2 levels, at the same time vigilance was achieved in terms of hydraulics and system safety features. The information was also leveraged for project sequencing and approach of clustering of much higher CO2 fields (&gt;20 mol%) to common facilities with contamination management instead of individual facilities with optimized blended CO2 levels. Opportunities were identified for maximum utilization of sweet fields by necessary amendment in the network, distribution of sweet and sour fields were organized which facilitated operationalization of priority of supply (considering commercial obligations in place) for fields containing CO2 &lt; 20 mol %.

Opportunities were identified for High CO2 fields by leveraging on the sweet pockets by aligning the appropriate feeders to have optimized value creation. The modeling created smart approach that assisted in addressing and mitigating the risk, correspondingly minimizing uncertainty for the high CO2 fields monetization. It also elaborated on the customer focused approach that includes end to end modeling that enabled CO2 mapping at organizational level.