Publications

MuaraEnim is located in South Sumatera, one of largest energy resources in Indonesia. Many formations in South Sumatera contain coal which may act as reservoir of methane. To study the characteristics of coal as methane reservoir, some samples of coal were collected in MuaraEnim to be analyzed in Rock Physics laboratory. Some studies were carried out on MuaraEnim coal samples. These samples contain many types of porosity, i.e.: fracture porosity and matrix porosity. Coal’s fracture porosity has wide range in size and also unique. Porosity of coal can be seen clearly without microscope but some micro fractures still can be observed in Nano scale using SEM (Scanning Electron Microscope). This phenomena show that porosity of coal is unique, and has different characteristic compared to the porosity of sand. Fracture pattern and pore structures study of coal reservoirs are very important, because it is directly related to the storage mechanism of gas in CBM reservoir, therefore this is very important parameter for calculating of CBM reserve. The porosity is still detected in matrix of cleat coal itself. This phenomenon causes the larger porosity content of CBM than conventional sandstone reservoirs. It is because matrix still contains smaller pores. Seismic wave parameter plays very important role in characterization of coal bed methane reservoir. Samples of MuaraEnim coal were measured in various seismic wave parameters and various * Rock Fluid Imaging Lab. ** Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR) *** PT Bukit Asam (PTBA) **** Institute of Technology Bandung reservoir conditions, i.e.: Vp, Vs, density in various pore fluid and pressure. Coal samples weremeasured using Seiscore physical modeling, it is for modeling the relationships among Vp, Vs and density in various pressure of reservoir, i.e.: pore pressure and overburden pressure. Almost all of elastic wave parameter of coal as CBM reservoir is modeled in various fluids, overburden pressures and pore pressures. Pore pressure is one of most important parameter in CBM exploration to check whether pore pressure is still original or not. By means rock physics data from Seiscore physical modeling, relationship among pore pressures and AVO parameters can be produced, result of modeling shows that the parameter of AVO can differentiate the variation of pore pressures. The orientation of coal’s cleat gives also influences to seismic wave parameter of P and S wave. Keywords: CBM, Seismic Rock Physics, Pore Pressure, Porosity