E. Ogoun, E. Gobina
Robert Gordon University,
Keywords: nanoporous, flowrate, porosity, permeability, fluid saturation, unconventional gas, reservoir
Summary:Natural gas was for quite a long time regarded as an unwanted by-product of oil exploration and production that was mostly flared to the atmosphere. This happened because there was no feasible economic means of bringing it to the market, this gas was considered stranded. However, in most cases the quantities were huge but due to high carbon content could not be brought to the global market. Now, with the availability of new technological advances the exploration and production of challenging unconventional gas reservoirs have become economically viable. In this work ceramic core technology, which has gained significant attention over the last decades, will be applied to enable laboratory study of the permeation of gases continuously under mild conditions and under realistic pressure drops with very low consumption of energy with no required additives. This study is designed to mimic the effect of petrophysical parameters on gas flow in a tight reservoir using nano-porous core samples. Experiments were carried out, involving a procedure that requires the release of different gases contained in a gas cylinder to an assemblage of nano-cores fitted into the center of an anulus of a shell and tube arrangement. The nano-core samples had varying pore throats and were studied at different temperature and pressure conditions. Suitable data were collected and analyzed with statistical tools to showcase the influence of porosity, permeability and fluid saturation on the flowrate associated in extracting gas from unconventional reservoirs. The results established that several factors impact on the accumulation and migration of gas in an unconventional gas reservoir and these factors determine the rate at which gas flows from the reservoir to the well-bore.