Techno-Economic Analysis of GTL, LNG, CNG and GTW for Monetizing Marginal Remote Gas Field: A Case Study

Abstract

Abstract Monetization of marginal gas field is often a challenging task, wherein quantum of gas available is very small. In remote field unavailability of gas consumers, lack of infrastructure, long gestation period makes it an unattractive investment. In this paper, a comparative analysis of available technology helped to take a wise decision among available technology to monetizing marginal fields For early monetization options such as power generation, utilize it as compressed natural gas (CNG), Gas to Liquid (GTL), Liquefied natural Gas (LNG) and Gas to wire (GTW) was explored. A detailed techno-economic analysis of these have been carried out which enabled us to take a concrete decision. Scenarios such as variation of production performance, tweaking the production profile for optimum return on investment, option of utilization of diesel for internal or sale to oil marketing company (OMC). Sensitive analysis has been carried out to draw conclusion to achieve the best possible return in investment. CNG is one of the way to monetize gas by compressing it up to 250 kg/cm2g and then transporting it into a cascade mounted truck. In a remote location, where consumers are not available nearby, transportation of CNG is a difficult task and would require multiple stages of transportation & cascade storage. LNG is basically natural gas converted in liquid form by cooling it to –260° F (–162° C). Changing it from a gas into a liquid that is 1/600th of its original volume and thereby transportation will become easier. In GTW, gas is used to generate power. In GTL, gas is catalytically converted into useful product such as synthetic crude, diesel, kerosene etc. Earlier, conversion of gas into diesel was not only cost intensive but also requires high space and hence, generally not accepted for small volume of gas. A detailed techno-economic analysis depicts that conversion of gas into diesel is attractive in investment but has an issue with Indian standard quality required for IC engine. CNG or LNG which was once non-viable are viable with reference to current open market scenario This approach will open a plethora of opportunity and will open a flood gate to monetize the marginal gas field which time and again remains stranded. Apart from marginal gas field, the said approach is also useful for minimization of flare gas and will contribute significantly in energy transition.