SEISMIC ATTRIBUTES OF RESERVOIR E34 AT X FIELD

X Field is located in the west-central Malay Basin, offshore Malaysia. The X field main
reservoirs are aligned on a stacked pattern within an anticline structure. Seismic attributes
will be utilized to understand the faults distribution and extension of hydrocarbon sand of
the E34 reservoir within the X field. The E34 interpreted horizon on seismic and the
faults interpretation are incorporated to extract the hydrocarbon sand in the reservoir.
The E36 reservoirs are characterized by massive bodies of sand. The attribute extraction
shows that the distribution of sand bodies ties well with the structure map. Three different
amplitude related attributes were utilized to determine the hydrocarbon sand extension.
Crucial assumptions made in this project were the E34 reservoir is homogenous
throughout the X field and the amplitude within the hydrocarbon sand zone does not
show any anomalous change. The amplitude variation on several exploration and
deviated wells are studied by observing the amplitude values given within the
hydrocarbon zone. The well markers and related well logs are used to verify the
hydrocarbon zone at each location. The hydrocarbon zone observed on well logs is
approximately 36 ms. Therefore, the attribute extraction are conducted on a window
basis. The minimum distance from E34 horizon showing hydrocarbon presence is 4 ms.
The windows are extracted between 4ms to 36 ms below the E34 horizon, which
apparently give the amplitude values for the hydrocarbon sand. First, the attributes are
extracted for a wider range of amplitudes observed on seismic sections at the well
location. Later these values are compared between windows of different depths to get
the nominal value for hydrocarbon sand. The attribute analysis in this report was
conducted for the entire X field. The main concentration was given to the Unit area
where wells are available. Therefore, users may be able to determine expected possible
hydrocarbon distribution at particular depth (ms) within the E34 reservoir. More wells
need to be drilled in the Western and Eastern areas to understand the amplitude
variance. These results can be incorporated to change the current amplitude limits for
each attribute and define a new range for the Eastern and Western areas.