Mature field Development to Periphery Area: Tambora West Flank development

Tambora gas field, discovered in 1974 is located in a swamp area at the apex of Mahakam Delta, and it is adjacent to Nilam field, which is operated by another operator. Geologically, the Tambora and Nilam Fields have the same anticline structure that originates from the sediment provenance west of Kalimantan as reflected in present day Mahakam Delta. Therefore, this study aims to analyze the challenges to unlock the potential of the west flank area of Tambora Fields. The geological synthesis of both Tambora and Nilam fields shows similar net sand and pay distribution in lateral and vertical proportions. Most developments in the Tambora Anticline area are in the crest and the distances between wells are ~100-200m. Challenges to unlock potential in flank areas are derived from the limitation of wells and seismic data. Based on data and knowledge of the flank areas in both fields, the west flank has better productivity compared to the east. Therefore, geological synthesis is conducted in the west flank area to define hydrocarbon and reservoir properties. Furthermore, channel models were made from 2D seismic scouring, controlled by the continuation of well log channel facies in the anticline crest area. Based on the preliminary approach, 3 wells were proposed to unlock west flank Tambora potential and were integrated into the plan of development. Primarily, dynamic uncertainty affects the potential of the west flank since production in the anticline crest area is enormous, and the uncertainty was analyzed by drilling one recent well. The result shows that hydrocarbon in the flank is not fully connected with the anticline crest area and has proven the sidebar heterogeneity concept. These gave more confidence to seek further positive results and develop west flank Tambora to sustain Mahakam production in the future.