FACIES AND RESERVOIR CHARACTERISTICS OF CROSS-BEDDED AND PLANE-BEDDED SANDSTONE

Most of Malaysia reservoirs are coming from sandstone formation. Sandstone is a sedimentary rock. Sedimentary rocks are formed when loose are laid down and with time, these sediment might located thousand of thick feet. Due to compression of accumulate overlying sediments, with the increase of heat and pressure, the physical and chemical are altered to form sedimentary rock. One of the features of sedimentary rock is stratification. The stratification can be categorized into two departments, planar stratification and cross stratification. There are terms that always be used to explain the stratification. For example like stratum (plural is called strata) which is defined as individual layer in a sediment or sedimentary rock that is produced by deposition. The terms like lamina (laminae) and bed (beds) can be defined as a stratum that is less than one centimetre thick and greater than one centimetre thick respectively. Correspondingly, stratification is termed either lamination or bedding.
Cross-bedded and plane-bedded of sandstone are the sedimentary structures to be study in this research. The area of study is included the facies analysis and reservoir characteristics. A facies is defined by a particular set of sediment attributes like lithology, texture, suite of sedimentary structures, fossil content and others. In the field and during the early stage of study, facies should be referred to only the descriptive sense and the interpretations in term of process and environment come later. The specifications of reservoir rock are the capacity to store hydrocarbon and the ability to allow hydrocarbon to flow through a conduit. The properties that affected the capacity and flows are porosity, permeability, fluid saturation and capillary pressure.
The fieldtrip and laboratory examinations are several of activities had been proposed to be implementing in the project. Fieldtrip to the area of study which is south region of Bintulu is believed can help the author to collect samples from there and exposed to the area of study. Laboratory examinations are important in analysing samples and hence solve the questions of uncertainty issues during the early fieldtrip. The uncertainty issues are like porosity, permeability, grain size and others. The
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laboratory equipments that suggested to use are Rotap shaker for sieving, SME for observing the unseen particles, and POROPERM for determining porosity and permeability.
Keyword: Cross-bedded, Plane-bedded, Sandstone, Facies, Reservoir characteristics, Fieldtrip, Laboratory works.