Publications

A number of siliciclastic low resistivity pay (LRP) reservoirs are productive oil and gas reservoirs in Offshore North West Java (ONWJ). These reservoirs are unique and challenging in exploration and production activities. The challenge is dealing with uncertainties that subject to petrophysical improvisation such as water saturation and pay zone thickness. petrophysical analysis were performed in the shallow marine sandstone reservoirs for three wells,WJ-10, WJ-11 and WJ-12ST.. Core and cutting data indicated that LRP is caused by fine grain laminated shaly sand, superficial microporosity and possible electronic conduction, that may affectthe reading of conventional resistivity log not showing real resistivity of the reservoir. Many lesson learnt from the LRP case has shown thatthe real reservoir irreducible water saturation from core datahas a higher resolution than the conventional log data. In general all LRP causes could be clustered into two main groups, high capillarity and low resistivity log resolution. Solutions for both causes are electrical parameter modification and vertical resolution analysis improvement. This solution is named as MAINE Petrophysical Method. This method involves high resolution core sedimentology observation, clay distribution analysis and also integrated analysis of Porosity-Permeability-Irreducible Water Saturation Transformation (2PST) and Type Curve Analysis (TCA). The outputs of this method arevertical geometry of LRP reservoir, clay distribution type, high resolution reservoir rock type, modified cementation exponent (m) and saturation exponent (n) related to rock type and also reliable water saturation. This method has been guaranteed by 3 porosity-permeability core basic validation steps in order to provide the best results, A MAINE Petrophysical Method shows an average water saturation result is around 66% while the previous method water saturation is around 86%. A decrease in water saturation of 23% or equal to an increase in oil saturation of 142% has been validated by well testing and dynamic analysis by surrounding proven fields.