IN SITU WETTABILITY DETERMINATION A CASE STUDY OF CARBONATE RESERVOIR NGIMBANG FORMATION

• Main Author: Andriani, Rini
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43046
• Institution: Institut Teknologi Bandung

The efficiency of the oil recovery process from the reservoir may depend on the rock wettability. Several investigations have shown that the wettability gives a major influence on the displacement of oil by water in an oil reservoir. However, clay content is one of the factors that may influence the nature of rock wetness. Furthermore, a clay with a water-wet preference (influenced by mineral composition) will tend to bind water and form a continuous electrical path so that it will block oil to contact with the rock. The purpose of this study is to determine rock wettability in carbonate reservoir, especially the Ngimbang formation by using two methods Krygowksi & Cluff (2012) and the Al-Hilali method (2015). Hydrocarbon composition, SCAL, petrography, SEM and XRD are used as supporting data to investigate rock wettability. Capillary pressure curves are reconstructed based on the interpretation of water saturation logs and pressure test to gives a better representation of the reservoir conditions. The results of the study show that the major content of clay mineral is a mixed-layer illite/smectite (I/S) which is known to have greater water-sorption compared to other clay minerals that could give a hydrophyilic characteristic. Result of this study show that is close to 2 in clean formation. The value continues to decrease along with the rock shaliness. By combining well log, core, and pressure data (MDT and DST) analysis shows that the carbonate reservoir Ngimbang Formation is water-wet.