Analisis total organic carbon (TOC), brittleness index (BI) maturity, dan atribut seismik untuk identifikasi karakteristik potensi shale oil : studi kasus formasi talang akar, cekungan Ardjuna Tengah = Analysis of total organic carbon (TOC) brittleness index (BI) maturity and seismic attributes for characteristics identification of potential shale oil : a case study of talang akar formation Central Ardjuna basin / Gilang Hamzah Fansury