Interpretasi Geologi Bawah Permukaan dan Delineasi Cekungan Salawati Wilayah Sorong dan Sekitarnya Berdasarkan Analisis Spektral Serta Pemodelan 2D dan 3D Data Gayaberat
AbstractThe Salawati Basin is a matured sedimentary basin andÂ Â hydrocarbon has been produced since 1936. Several oil and gas fields have been produced in carbonate reefs and anticlinal structures. The purpose of this studyÂ to determine basement configuration, structure patterns andÂ to delineate the Salawati Subbasin withÂ Â expecting to predict depocentre and the thickness of sedimentary rocks in this area. Gravity data analysis was done by using spectral analysis, high-low pass filter, 2D and 3D modeling. The result of spectral analysis shows thatÂ Â the average thickness of sedimentary rocksÂ in this research area is 3.4 Km, and the amount of sedimentary subbasin that can be delineated are five subbasins.The most prospect area is around the Sele Strait as a basement high (possibly anticlinal) supplied from two depocentre fromÂ Â the Sele Strait and Klasaman subbasin. The structure pattern that indicated from residual gravity anomaly shows basement high (anticline), transform fault and normal fault.Â The 2D and 3D modeling results show that theÂ basement in the research areas are metamorphicsÂ with density value 2.85 gr/cc, the layer above basement is pre-Tertiary sedimentary rock with density value 2.45 gr/cc, above the pre-Tertiary sediment is Paleogen sedimentary rock with density value 2.5 gr/cc, the top layer is Neogen sedimentary rock with density value 2.35 gr/cc. Based on the data and information, this area isÂ Â probable attractive for further investigation, especially regarding sedimentary subbasins that make oil and gas can be exploited economically.
Keywords : Gravity, spectral analysis, 2D and 3D gravity modeling, Salawati Basin
Amri C.H., Sanyoto,P., Hamonangan,B., Supriyatna,S., Simanjuntak,W., Pieters,PE., 1990. Peta Geologi Lembar Sorong, Irian Jaya, Pusat Penelitian dan Pengembangan Geologi, Bandung
Blakely, R. J., 1996. Potential Theory in Gravity and Magnetic Applications, Cambridge University Press, Cambridge.
Charlton, T.R., 2000.Tertiary Evolution of the Eastern Indonesia Collisional Complex. J. Asian Earth, Sci. 18.
Elkins, T.A., 1951. The Second Derivatif Method of Gravity Interpretation, Geophysics, v.23, h.97 -127
Hamilton, W., 1979. Tectonic of the Indonesia Region, US Geoogical Survey Professional Papers, 1078.
Ningrum, T., Kadir, W. G. A., Alawiyah, S., Wahyudi, E. J.. 2011. â€œStudi Identifikasi Struktur dan Prospek Hidrokarbon Daerah Frontier pada Cekungan Melawi-Ketungau, Kalimantan Barat dengan Metode Gayaberatâ€. Jurnal Teknologi dan Mineral Vol. XVIII No. 2.
Pirttijarvi, M., 2008. Gravity interpretation and modeling software based on 3-D block models. User's guide to version 1.6b. Department of Physics Sciences. University ofOulu. Finlandia.
Riadini, P., 2009. Kinematika Sesar Sorong sebagai implikasi terhadap evolusi struktur daerah Seram, Misool dan Cekungan Salawati, Thesis Magister Teknik Geologi ITB, Bandung.
Sarkowi, M., 2010. Identifikasi Struktur Daerah Panasbumi Ulubelu Berdasarkan Analisa Data SVD Anomali Bouguer. Jurnal Sains MIPA :111-118.
Satyana, A.H., 2009. Emergence of New Petroleum Systemin The Mature SalawatiBasin : Keys From Geochemical Biomarker. Proceedings, Indonesian Petroleum Association, Thirty-Third Annual Convention & Exhibiton May 2009.
Satyana, A.H., Salim,Y., and Demarest, Jim D., 1999. Significance of Focused Hydrocarbon Migration in the Salawati Basin : Controls of Fault and Structural Noses. Proceedings, Indonesian Petroleum Association, Twenty Seventh Annual Convention & Exhibiton October 1999.
Satyana, A.H., 2003. Re-evaluation of the sedimentology and evaluation of the Kais Carbonate Platform, Salawati Basin, Eastern Indonesia : Exploration significance. Proceedings, Indonesian Petroleum Association,Twenty-ninth Annual Convention & Exhibition, October 2003
Satyana, A.H., 2008. Aromatic Methylphenanthrene Biomarker and Maturity of Oils Keys to Identifying New Active Source Rocks in the Salawti Basin, Indonesia. AAPG International conference &exhibition, October 26-29, 2008, Cape Town, South Africa.
Setiadi, I., 2017. Basement Configuration and Delineation of Banyumas Subbasin Based On Gravity Data analysis, Jurnal Geologi dan Sumber Daya Mineral, Vol. 18 N0.2, Mei 2017, hal. 67 - 76
Talwani, M., Worzel, J. L., and Landisman, M., 1959. Rapid Gravity Computations for Two-Dimensional Bodies with Application to the Mendocino Submarine Fracture Zone, J. Geophys. Res., 64(1): 49-59
Telford, W. M., Geldart, L. P., Sheriff, R. E., and Keys. D. A., 1990, Applied Geophysics, Cambridge University Press, Cambridge.
Zahra, H.S. and Oweis, H.T., 2016. Application of high-pass filtering techniques on gravity and magnetic data of the eastern Qattara Depression area, Western Desert, Egypt. NRIAG Journal of Astronomy and Geophysics, 5 (1):s 106 -123. http://doi.org/10.1016/j.nrjag.2016.01.005
Authors who publish articles inÂ Jurnal Geologi dan Sumberdaya Mineral (JGSM.Geologi) agree to the following terms:
- Authors retain copyright of the article and grant the journal right of first publication with the work simultaneously licensed under aÂ CC-BY-NC or The Creative Commons Attributionâ€“ShareAlike License.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access)