KARAKTERISASI RESERVOIR DAN PERHITUNGAN VOLUMETRIK CADANGAN MINYAK MENGGUNAKAN ANALISIS PETROFISIKA DAN INTERPRETASI SEISMIK PADA FORMASI TENSLEEP DI LAPANGAN TEAPOT DOME, CEKUNGAN POWDER RIVER, WYOMING

CAHYADI, RUDI, Sudarmaji

2016 | Skripsi | FMIPA

Stock tank original oil in place (STOOIP) calculations can be obtained by doing petrophysics analysis and seismic interpretation. By petrophysics analysis obtained petrophysics properties such as volume shale, porosity, water saturation, permeability, and reservoir thickness such as gross, net sand, net pay and net to gross, whereas by seismic interpretation obtained wide area of hydrocarbon zone. Then performed mapping distribution of those petrophysics properties and reservoir thickness. That parameters was used to calculate hydrocarbon reserve in Teapot Dome field, Tensleep sandstone formation, Powder River Basin. This research used deterministic method in Geolog 7.0 software. Shale volume was determined from gamma ray log calculation method, effective porosity was calculated by neutron-density method, water saturation was determined based on Archie’s equation, permeability was calculated by Wyllie and Rose equation whereas gross, net sand, net pay and net to gross was determined from lumping. The Research result of seven drilling wells shows that Tensleep formation had average value of shale volume about 36.69 %, effective porosity about 7.4 %, effective water saturation about 53.37 % and permeability about 79.57 mD. Tensleep formation also had average reservoir thickness of gross about 27.65 feet, net sand about 14.53 feet, net pay about 8.49 feet and net to gross about 0.39. From the map of petrophysical properties distribution can be obtained a good quality zone reside at the south-eastern. From the result of volumetric calculation obtained oil reserve in place as big as 77.24 MMBO.

Kata Kunci : Petrophysics analysis, reservoir evaluation, volumetric, STOOIP, Tensleep formation, Teapot Dome