SCALES AND CHARACTERISTICS OF HETEROGENEITY IN SANDSTONE RESERVOIRS (AIRPORT ROAD, MIRI, SARAWAK)

Heterogeneity in a hydrocarbon reservoir is referred to non-uniform, nonlinear
spatial distribution of rock properties. Characterizing rock permeability and its
special distribution in a heterogenous reservoir is a problem with no direct and
known solution. This project focused on characterization of porosity and
permeability of the sandstone reservoir of Miri Airport Road Formation. This
objective is achieved by examining some of the petrophysical properties and rock
physics samples (such as porosity and permeability). Outcrop belonging to the
hydrocarbon bearing Miri formation of Miri Airport Road is roughly 551cm in
thickness. The study area consists of six (6) distinctive facies (facies A, B, C, D, E
and F). Each facies are differes in thickness, facies internal structure, grain size,
porosity and permeability. Different grain sizes, facies internal structure, flow
barriers, presence of shale contents play significant effect to porosity and
permeability which makes the reservoir heterogenous. Among thses six (6) layers,
the best sandstone for reservoir is layer A because it has a net-to-gross thickness of
23%, porosity value of 26.06% and permeability value of 76.58 mD.