Publications

Fluid interpretation of new drilled well is commonly performed by evaluating well log data focused on single well newly drilled, even though there are some data from surrounding wells which has not only log data but also downhole fluid analysis and perforation data. If the surrounding wells data taken into account in well correlation, it is usually utilized by only comparing Resistivity value of each well. It is not a proper utilization and sometimes could lead missed interpretation because Resistivity log is depending on clay content, water salinity, and also mineralogy.

A new technique of fluid interpretation called as Multiwell Dual-Log Crossplot (MDC) has been developed in Pertamina Hulu Mahakam to properly utilizing surrounding well data to boost confidence level and accuracy of fluid interpretation. This new innovative technique is performed by evaluating the new drilled well data together with existing surrounding wells data by using crossplot. It is the continuation of Pertamina Hulu Mahakam (PHM) unique technique called Mahakam Integrated Fluid Identification (MIFI). In order to avoid misleading due to water salinity difference, the evaluation is performed at the same stratigraphic marker by considering facies and depositional environment. Fluid interpretation is performed with Gamma Ray-Resistivity crossplot for hydrocarbon and water differentiation, while for gas and oil differentiation is performed by using Density-Neutron and Gamma Ray-Neutron crossplot.

The result of this technique has been evaluated by using downhole fluid analysis (FA) and perforation results. The fluid interpretation by using this technique has high confidence level and in line with downhole FA and perforation result. This technique is also playing significant role in order to optimize downhole fluid analysis (FA) and including gas or oil reservoirs in the future perforation candidates to maintain production.

This paper details the method and its application in all of Mahakam fields, East Kalimantan. This technique, referred to as Multiwell Dual-Log Crossplot (MDC), provides a new alternative technique that could be applied in oil and gas fields outside Mahakam, by better identifying hydrocarbon content & optimizing the data acquisition.