Print this pageAAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Geological Evaluation and CBM Potential Development in Tanjung Enim Area, South Sumatera, Indonesia
(1) Coalbed Methan Division, Pertamina, Jakarta, Indonesia.
The study is conducted to evaluate the geological aspect, assess the CBM potential and its development plan in the study area. This study covering area approximately 309 km sq where is located in southern part of the South Sumatera Basin. This basin is well known as coal-bearing basin, with good thickness, quality and lateral continuity of coals. The coal seams are lies within the Muara Enim Formation that was deposited during the Late Miocene to Early Pliocene in humid-tropical deltaic system. Major thrust fault with NW-SE trending are quite dominant in this formation.
Muara Enim Coal can be classified into four coal groups, in a series from the oldest to the youngest are - what we call it - M1 , M2, M3 and M4. M1 consist of Kladi and Merapi coal seams. M2 consist of Petai, Suban and Mangus coal seams. M3 consist of Benuang and Burung. While M4 consist of Kebon, Benakat, Lematang and Niru seams.
CBM targets in this area are M1 and M2. Those coal seams are proved as the best coals identified in the study area and lies in 300 - 600 meters depth intervals. In the central area of the study, M2 coal seams become the main target of coal mining. Most of the coals in the study area are sub-bituminous in rank.
Some of coal samples and data are collected from the mining outcrops. Both proximate and ultimate analysis are conducted to characterize the coal properties. In this study, we used Kim’s formula to calculate the gas content, while gas in-place was defined by using volumetric method. This study has resulted the CBM potential in three cases of gas in-place value: 701 bcf (best case), 491 bcf (base case) and 350 bcf (worst case). This result gives us a fair economic resources.
Based on geological modelling, seven wells proposed in this area, which is particularly located in the eastern part of the study area.