Browsing by Subject "reperforating"

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Some considerations regarding the unconventional gas reservoirs in Romgaz
(2011) Ştefănescu, Dan-Paul; Vlasín, Ioana; Piteiu, Marcel A; Petrescu, Valentin
The need for discovering the alternative energy resources, beside the classical and conventional ones, became nowadays a continuous challenge and it seems to become a viable solution in order to overcome the worldwide energetic crisis. If the concept of unconventional gas is nowadays more frequently used in world oil and gas industry, in Romgaz it hasn't been implemented and developed until now, even if unconventional reservoirs have been already tested in the past, without knowing and using this terminology. The unconventional gas reservoir is related to a low permeability formation, that is producing mainly dry gas. The most part of the low permeability reservoirs are developed in sandstones, but high amounts of gas have been also produced in carbonates, shales and coalbed methane. However, today we can say that our attempts are also very timid, but we are often encouraged by the successful results obtained during the wells testing. Based on Romgaz experience, we could classify our unconventional gas reservoirs in two main categories: shale gas and tight gas formations. After a short description of the general concept and what an unconventional gas reservoir means, our paper will present some case studies from different areas and geological units, belonging to Romgaz, which provide the existence of natural gas in these types of reservoirs. We mention that the old Romgaz concept regarding well testing was related to perforating only the porous permeable formations, but some experiments developed in the last years proved to have good results in unconventional formations. Although it's very clear that extraction of natural gas from these reservoirs is more difficult and also more expensive than that from the conventional reservoirs, due to the new technologies which would be perhaps involved (hydraulic fracturing, acidizing, etc.) we are fully convinced that what was considered unconventional in the past, will become conventional in the future.