Upper Sihapas Sandstone as The New Play in K Field


“K” Field is a mature oil field located onshore, within the Padang Island of Malacca Strait Block, Riau
Province, Sumatera. The main producing reservoirs are the Lower Sihapas sandstones, whereas the Upper Sihapas
Formation was not a target and never put in production in “K” field due to higher shale content, thinner bodies, and
limited in volume (sand lenses). After having produced since 1988, “K” field became very mature, oil production
decrease and water saturation getting higher. Infill drilling, regular Workover, and well servicing are being
performed as the effort to face production decline. The well data (E-log and mudlog data) combined with 3D seismic
data are a powerful tool to conduct sequence stratigraphy studies. Based on sequence stratigraphy correlation, Upper
Sihapas interval in “K” field is divided into 4 different sand bodies. Seismic attributes, such as RMS and wave shape
attribute, had also been conducted in order to identify the sand distribution. Based on petrophysical study, these
sandstones have low to moderate porosity and low permeability. The volumetric gives reserve of these Upper
Sihapas sandstone is 2.3 mmstb (P50). While drilling MSK-34 well in the eastern compartment of “K” Field, there is
significant oil indication and high gas reading in the Upper Sihapas sandstone and it can be correlated to the
surrounding wells. Since its dynamic behavior is poorly understood, this transgressive sand series is needed to be
tested. The testing in MSK-27 gave an encouraging result with initial production 300 bopd, 1% of BSW.