Anisotropic properties identification of Naintupo Formation, Tabul Formation and Tarakan Formation (Tarakan Sub-Basin) using anisotropic parameters determination method from P-wave seismic diffraction function

International Conference on Earth Science, Mineral, and Energy

地球科学;矿业工程;能源学

Ronoatmojo, I.S.^1 ; Burhannudinnur, M.^1

Faculty of Earth Technology and Energy, Trisakti University, Campus A, Jl. Kyai Tapa No.1, Grogol, Jakarta

11440, Indonesia^1

关键词: Anisotropic property;    Diffraction methods;    Identifying methods;    Parameters determination methods;    Pre-stack depth migrations;    Pre-stack migration;    Sedimentation pattern;    Seismic diffractions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/212/1/012075/pdf
DOI  :  10.1088/1755-1315/212/1/012075

来源: IOP

【 摘 要 】

The anisotropic property of sedimentary rocks are influenced by geological processes such as sedimentation pattern, grain size and grain sorting, hence it might be a significant impact to the seismic wave propagation. An identifying method of the anisotropic property is done by deriving the relationship between group velocity and phase velocity of a P-wave seismic diffraction function. Subject to be studied are Naintupo Formation, Tabul Formation and Tarakan Formation which are lied in Tarakan Basin, these formations are an anisotropic sedimentation products, generally composed of sandstone and shalestone by thickness more than 1000 meters. In the seismic section, it is shown by range of 1500 msec - 3000 msec. The diffraction function observed at a point of the diffractor due to the normal fault. There are 3 points of observation, SP.1374, SP.1375 and SP. 1376 which assign anisotropic value δ and , where the δ value is in the range of 0.26 - 0.28 and the value is in the range of 0.46 - 0.72, picked from 42 samples. Furthermore, Pre Stack Depth Migration was carried out through 2 velocity models; there are velocity model with anisotropic parameters δ and derived from diffraction functions and the constrained velocity inversion method. After the curved ray pre-stack migration process, it is found that the velocity Vp (900) of diffraction method faster than the constrained velocity inversion method, where the δ value for both methods are 0.35 but the for the diffraction method is 0.4 and the constrained velocity inversion method is 0.35. Regarding to the result of the 2D NW-SE PSDM stack, there is a more obvious fault compartment observed from the diffraction method.