Publications

South Sumatra Basin has large quantities of coal bed methane, especially in Muara Enim Formation, South Sumatra Basin. Commonly, Muara Enim Formation is divided into M1-M4 as used by Shell Mijnbouw in the late 1970’s. This division was based on lithostratigraphy where certain coals became formation markers. Several difficulties have arisen when using this nomenclature especially for coal seam identification and correlation since it is mostly chronostratigraphically misinterpreted. Within the complex stratigraphy of the Muara Enim, parasequencing offers better resolution for coal seam identification and correlation. Based on this concept, the Muara Enim Formation is divided into seven environmental parasequences of the tidal influenced transition based on eight facies groups classified by the depositional environment based on interpretation of rock facies lithology and GR log deflection pattern. The facies are prodelta, delta front, mouth bar, sub-tidal, inter-delta, supratidal, lower shoreface, and upper shoreface (Figure 2).To determine the continuity of coalbeds, parasequences were integrated with seismic data. Interpretive seismic techniques used were preconditioning data (filtering), multi-attribute analyses and inversion. Filtering seismic data prior to acoustic impedance (AI) inversion produces better results. In situations where wells are located far from seismic lines, calibration with logs is problematic and inversion produces less than maximum results. Multi-attribute approach can optimize the results. Integration of the filtering, AI inversion, and then multi-attribute & neural network methods produce the best output to identify coal seams, their distribution and continuity.