Perpustakaan Digital ITB

Shale gas, as the one of unconventional gas reservoir, plays a critical role for fulfilling the fast rate of gas consumption demand in the future, that values up to 1.4% increasing per year. However, both caracteristic and production method of this reservoir shows a particular complexity by itself to be analysed and extracted. It needs further study to help identifying the characteristic more comprehensively so that avoiding the mis-intepretation and mis-prediction at the end of the day that can lead to wrong determination on techno-economic analysis of shale gas development project. One of the unique of shale gas reservoir characteristic is about nano-pore system which leads to unique phase behaviour under confinement effect. Therefore, the effects of nano-pores on the critical properties of the confined gas in the Barnett Shale will be investigated. This study focuses on analysis of fluid reservoir properties and phase envelope or critical properties shifting due to the confinement effect of several nano-pore sizes that are 2 nm, 4 nm, 6 nm, 8 nm, 15 nm, and 30 nm. Therefore, 7 models consist of 6 confinement and 1 unconfinement cases are built by the use of Peng-Robinson equation of the state (EOS). These models will be as the fluid models for the input of reservoir simulation process through CMG- GEM simulator. Finally, after building the reservoir models, many simulation runs were carried out in order to study the impact of the pore confinement on the gas reservoir’s performance. This study also focuses on different values calculation of shale gas reserve estimation by the use of Monte-Carlo method, based on the result of fluid reservoir properties analysis in different pore size. Monte Carlo’s variables are set to be normal distribution except the gas formation volume factor, that follows particular distribution of pore size distribution model on Barnett shale gas reservoir. Both studies results that several gas properties such as gas formation volume factor, gas deviation factor, gas viscosity, and gas density show deflection along the pressure profile, compared to the conventional one on the same compositional model. This deflection heads to little different of gas reservoir performance, such as different values up to 5 % on recovery factor and 2 % on cumulative gas production and also gives significant differences enough of gas initial in place estimation which is up to 11 % between conventional and the unconventional one. These results show direct implications in determining the gas-in-place and assessing the production potential of a shale gas reservoir under various confinement scenario.