PENENTUAN FASIES DAN ZONA PROSPEK PADA UMUR MIOSEN TENGAH-PLIOSEN AWAL SERTA PERSEBARAN ZONA PROSPEK PADA LAPANGAN TISA, BLOK KALOSI, SUBCEKUNGAN ENREKANG, SULAWESI SELATAN

CHRIS SAMANTHA S, Dr. Ir. Jarot Setyowiyoto, M.Sc.

2017 | Skripsi | S1 TEKNIK GEOLOGI

Lapangan Tisa yang termasuk dalam Blok Kalosi terletak di Subcekungan Enrekang dan berada di daratan. Pada lapangan ini ditemukan rembesan minyak dan mengindikasikan berkembangnya petroleum system di daerah ini. Kajian yang dilakukan adalah fasies dan lingkungan pengendapan, petrofisika untuk penentuan zona prospek, serta persebaran lateral zona prospek. Penelitian ini menggunakan dua data log, sebelas data seismik, dan data sekunder berupa core dan cutting dalam bentuk report. Analisis diawali dengan validasi umur kedua sumur dan dilanjutkan dengan analisis litofasies yang dilakukan dengan melakukan integrasi data log terhadap data core dan cutting. Analisis selanjutnya adalah penentuan fasies dan lingkungan pengendapan. Analisis petrofisika selanjutnya dilakukan untuk mengetahui zona prospek. Setelah analisis data sumur dilakukan well seismic tie. Bidang krono berupa FS-11 dan FS-12 dimasukkan pada seismik untuk melihat persebarannya. Persebaran zona prospek kemudian dilakukan dengan melakukan pemodelan PHIE dan Sw. Melalui penelitian, didapatkan 13 litofasies yang kemudian diasosiasikan kedalam delapan sublingkungan pengendapan, yaitu estuarine tidal bars, estuarine tidal flat, submarine channel, submarine slope, submarine lobe, prodelta, delta front, dan outer shelf. Rasio batupasir yang tebal pada lokasi penelitian terletak pada batupasir lowstand system tract dan dilanjutkan pada analisis petrofisika. Analisis petrofisika menunjukkan zona prospek berada pada interval 1265 m sampai 1382 m. Zona prospek tersebar di sisi barat Lapangan Tisa dan terjebak akibat sesar-sesar naik yang berkembang.

Tisa Field, part of Kalosi Block is located at Enrekang Subbasin in onshore field. In this field, oil seepage was found and indicated development of petroleum system. Some analysis, such as facies and depositional environment, petrophysics to determine prospect zone, distribution of prospect zone were interpreted. This research used two log data, eleven seismic data, and secondary data such as core, cutting, and biostratigraphy that were written in well report. Analysis began with age validation for both of the well and continued with lithofacies analysis by integrate it with core and cutting. The following analysis was facies and depositional environment analysis. Petrophysical analysis was done to interprete the prospect zone. The next step was well seismic tie. Chrono boundaries, such as FS-11 and FS-12 are spreaded through the seismic line. Prospect zone distribution was done by making PHIE model and Sw model. Research results showed 13 lithofacies were analysed and then associated into eight depositional subenvironments, such as estuarine tidal bars, estuarine tidal flat, submarine channel, submarine slope, submarine lobe, prodelta, delta front, and outer shelf. Thick sandstone ratio in research location was found in lowstand system tract sandstone and then followed with petrophysical analysis. Petrophyscical analysis showed that the prospect zone was found in 1265 m until 1382 m. Prospect zone was distributed in west side of Tisa Field and trapped as cause of the developing of reverse faults.

Kata Kunci : fasies, petrofisika, zona prospek