Publications

The Kakap PSC is located in the West Natuna Basin (WNB) within the SE prolongation of the Malay Basin. The PSC is split into North Kakap area with 1,501 km2 and the South Kakap area with 505 km2. The first discovery in Kakap PSC was KG Field in 1978. There are now eleven producing fields in the South Kakap area including KH, KG, KF, and KRA as the four major fields. The purpose of this paper is to demonstrate that the statistical analysis of the hydrocarbon column height data can be used to estimate productive area and gross rock volume for prospects. The method applied is using knowledge of the total column (crest to spill point), the total hydrocarbon column (crest to hydrocarbon contact), and the portion of the hydrocarbon column that is oil or gas. Cumulative probability plots of this data collectively, by reservoir and by fluid type, were made to assist in the analysis. A case study of the KH Field which has been producing for 28 years was selected as an example to prove the methodology applied in this study. Hydrocarbon column height data from all producing fields was used to generate several statistical distributions. The data clearly show that the hydrocarbon column heights can be represented as a lognormal distribution. The distribution of all column heights has sufficient sample size for high confidence in the composite distribution, though some individual reservoirs have smaller sample size and thus lower confidence. Using probability distributions of column height in conjunction with structural maps appears to be valid for the determination of the productive area extent of the potential hydrocarbon accumulations. These results suggest that a lognormal distribution of the analog hydrocarbon column height data can be used with high confidence in estimating the range of productive area and gross rock volume for improving the hydrocarbon reserves and resources estimates in the Kakap PSC area.