Reservoir Karbonat dan Rekah Alam

More than 50% proven reserves of oil and gas trapped in the carbonate and naturally
fracture reservoirs which has complexity and heterogen (note: geothermal reservoir have
always almost found in the naturally fracture reservoir). Carbonate reservoir is different
from klastic reservoir because it’s heterogeneity, surface chemical properties, and
multiporosity characteristic (dual or triple porosity)from rocks and fluid flow
system(interporosity flow). The rock surface chemical character produce wettability
between water-wet and oil-wet which can make water fingering easily happened, lower
production and lower recovery factor. These pores geometry heterogeneity on carbonate
reservoirs can be representated by dual porosity system which connected by
interconnection among fractures (vugs, channels) and rocks matrix. The amount of fluids
which stored on matrix and fracture and it’s easily path is the most important thing in the
strategy for exploiting this kind of reservoirs. The heterogeneity either areal or vertical,
wettability degree, and pores geometry multiporosity characteristic is the main contributor
which related each other and the uniqueness of the carbonate and naturally fracture
reservoir must be known by the Petroleum Engineering, Geology Engineering and
Geophysics Engineering student.