Analisis Log perhitungan OOIP lapisan TAN-23a lapangan JC
M Minyak dan gas bumi merupakan sumber energi yang sangat penting untuk pembangunan suatu negara. Untuk itu, perlu dilakukan peningkatan eksplorasi dan eksploitasi minyak dan gas bumi. Salah satu cara menentukan potensi minyak dan gas bumi adalah melakukan logging. Dari rekaman log akan diperoleh parameter-parameter petrofisik yang digunakan untuk perhitungan isi awal di tempat minyak dan gas bumi. Parameter-parameter tersebut adalah ketebalan lapisan (h), porositas (Ø) dan saturasi air (Sw). Sedangkan untuk menentukan luas area reservoir (A) ditentukan dari data geologi. Lapangan JC berada pada formasi Ngimbang dan memiliki 5 (lima) sumur, yaitu TAN-1, TAN-2, TAN-5, TAN-6, dan TAN-7 dengan lapisan TAN-23a. Metode yang digunakan untuk menghitung porositas adalah density neutron dan metode Indonesia untuk saturasi air. Cut-off lapangan JC untuk porositas 9%, Vsh 45%, dan Sw 60% dengan net pay 10 ft, 12 ft, 6.75 ft, 21 ft, dan 9.5 ft. Vsh rata rata ditentukan dari Gamma Ray Log dengan rata-rata 21.71%. Dari keseluruhan data, diperoleh volume bulk 56867.14 acreft, porositas rata-rata 17.94%, saturasi air rata-rata 40.47%, dan faktor volume formasi minyak awal 1.572 bbl/STB. Dan besarnya OOIP pada lapangan JC adalah 29.972 MMSTB.
O Oil and gas is an energy sources that very important for nation development. Exploration and exploitation of oil and gas are needed for keep the sustainable energy. One of method to determine potential areas of oil and gas is by doing logging. Petrophysics parameters is the result of well logging which is can be used to determine Original Oil In Place. The parameters are productive layer thickness (h), porosity (Ø), and water saturation (Sw). And the areas can be determined from geological data. JC field in Ngimbang formation have five wells, which is TAN-1, TAN-2, TAN-5, TAN-6, and TAN-7 with TAN-23a layer. The used method to determine porosity is density neutron and method for water saturation calculation is Indonesia method. JC field’s cut-off for porosity is 9%, for Vsh 45%, and for Sw 60% with net pay 10 ft, 12 ft, 6.75 ft, 21 ft, and 9.5 ft. Average Vsh is determined by Gamma Ray Log is 21.71%. And from entire data is obtained volume bulk 56867.14 acreft, average porosity 17.94%, average water saturation 40.47%, dan formation volume factor 1.572 bbl/STB. And the amount of OOIP in JC field is 29.972 MMSTB. In this formation produced through production wells, which the focus matter for this research are SP-01, SP-04, SP-06, SP-07 and SP-08. Where these wells produced non-assosiated gas. X field type of reservoir is dry gas reservoir. With water drive mechanism. There still no integration between subsurface-surface, so that in this final assignment will discuss about the making of interface performance to make original gas in place calculation and production optimization of X field easier. The amount of original gas in place and obtain from the simulation and manual calculation is 22,6 Bscf and 22,2 Bscf, with gas cumulative and recovery factor obtain from best scenario are 16344 MMscf and 73,75%.