New Approach of Synergizing Advanced Well Test Deconvolution, Rate Transient Analysis and Dynamic Modeling in Evaluating Reservoir Compartmentalization Uncertainty at K Field in Sarawak Basin; A Case Study

Abstract

This paper presents the result of synergizing advanced well test deconvolution, rate transient analysis and detailed reservoir modeling to answer the compartmentalization uncertainty demonstrated by downhole pressure data in K field located offshore Sarawak, Malaysia. The gas reservoir is well distributed within approximately 10 × 20 km area and divided into two fault blocks, east and west. The development only focused at eastern area. Based on earlier assessment during Field Development Plan (FDP) stage, no fault has been seen from seismic data interpretation within east area. However, the six years actual performance of the field address different understanding which suggesting possible compartmentalization. Several assumptions were made to reconcile the connected hydrocarbon initially in–place estimated from conventional material balance and static volumetric calculation, however it has led to inconclusive results. The paper draws on the strength of an integrated reservoir engineering studies that include analytical and numerical analysis. The general framework covers advanced well test deconvolution analysis which multiple Pressure Build Ups (PBUs) and flowing duration were interpreted. This helps in guiding reservoir characterization understanding further from the well and type of fault setting within the reservoir. In addition, Rate Transient Analysis (RTA) has been conducted to estimate the connected volume. Several interesting findings will be shared in this paper as well. The combination of these deconvolution and RTA works enhanced the understanding of reservoir compartmentalization which guided the history matching process done through dynamic model. The newly established workflow has reduced the efforts required in history matching process and gave clearer picture of the uncertainty of reservoir compartmentalization.