Exploitation of Stranded Gas Reservoirs Through Virtual Gas Pipeline in Pakistan - Techno-economic Analysis

Abstract Unavailability of gas transmission network near a hydrocarbon discovery leading to high pipeline infrastructure development cost and can cause delays in production or remain stranded, for several small gas reservoirs. This study explores the avenues of exploiting small and stranded gas reservoirs, through virtual gas pipeline by compressing the gas and transporting it through bulk transportation modules, primarily for use at Captive Power Plants, Processing Industries and CNG Stations. Virtual Pipeline (VP) system is being effectively used in many parts of the world for production from low volume stranded gas reservoirs. In Pakistan, presently, three stranded gas reservoirs are producing about 4 MMscfd gas through VP system in the Northern region of the country with the first such system being operative since 2010. Whereas, several opportunities exist in the Southern region of the country, as well, to add production from stranded gas reservoirs to national energy network through VP system. An economic model has been developed for the operators to assess the viability of VP vis a vis gas transmission pipeline and bring low volume stranded gas into the system. Results of economic model indicate that for small stranded discoveries with uncertainties in connected hydrocarbon volumes, production through VP offers better NPV than the conventional pipelines. Based on economic model, the concept of VP was implemented at one of PPL’s well, which commenced production on 27 October 2017, and currently producing 1.4 MMscfd gas and 110 bbl/d of condensate. Based on the collected data, if higher hydrocarbon volumes in place are estimated, the feasibility of laying feeder line to a nearest processing facility may be re-evaluated to compare with the currently utilized VP system.