Print this pageDeep Gas in the Neuquen Basin, Argentina
URIEN, CARLOS M., and TIMOTHY P. GARVEY
The Neuquen Basin is one of the largest hydrocarbons producers in Argentina. Located in a logistically favorable geographic position, the basin has yielded, since 1920, 1,869 MM Bbls of Oil and 6.95 TCF of Gas. Remaining proven reserves are in the order of 802 MM Bbls and 11.73 TCF. This basin has one of the most prolific sources with multiple stacked reservoirs.
Mesozoic sequences, over 6,000 m thick, within the deepest part of the basin, contain sizable amounts of gas within tight reservoirs. While traditional reservoirs are primarily sandstone and limestone units, some recent discoveries have yielded production from intervals with permeabilities <1 mD. Formation matrix fissures, disseminate hydrocarbons and abnormally high pressure gas accumulations have been detected in the deeper zones and are components of a new "play" in the basin. The traps, being primarily stratigraphic/diagenetic, differ from the conventional on the basin hinge line and rim.
Silicoclastic units with diagenetically - and antigenetically - altered clay matrices are important considerations in the drilling design, testing and completion programs. Historically, formation damage caused by improper practices has been an important factor, and, in numerous cases, has resulted in potential discoveries being overlooked.
Deep basin gas can be considered a new exploration and drilling frontier. Targets lie just beneath the traditional producing systems and are receiving increasing attention. Large potential reserves, increased market demand, and new pipeline networks and processing facilities make these deep gas targets economically attractive for exploration.