#TITLE_ALTERNATIVE#

• Main Author: SHAYLENDRA (NIM: 22014035), YUDHISTIRA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31805
• Institution: Institut Teknologi Bandung

<p align ="justify">The study of new hydrocarbon basin prospect is very important to be sought due to fulfill energy needs for mankind’s living, considering by the decreasing production of oil and gas in Indonesia. West Timor Basin is one of promising eastern Indonesian basin which has not been much considered about its existence. The exploration around West Timor Basin had been made since the last 40 years until 1999 with the drilling objective to test old rock formation in Permian, Triassic, and Jurassic. Banli-1 Well which located in West Timor Basin is yet to find potential commercial reserves. This fact is also supported by the lack of subsurface data in surrounding area, so those problems become a topic of interest for further investigation, particularly regarding the origin of hydrocarbon source rocks around the Kekneno and Kolbano area, West Timor Basin. Source rock identification is conducted on six traverses in Kekneno area to collect rock outcrops in several formations that allegedly has potential capability as a source rock. Those six traverses were Nisnoni Traverse, Valas Traverse, Tunsif Traverse, Besi Traverse, Nenas Traverse, and Oebaki Traverse. A total of seventy rock samples are collected and knowable about its organic material content, then twenty-one rock samples are selected to be processed in Rock-Eval pyrolysis analysis stage. Those selected rock samples are Atahoc Formation (Permian) with Aitutu Formation and Babulu Formation (Triassic), while Jurassic source rocks are represented by Wailuli Formation collected from the other data. Jurassic source rocks are represented by Wailuli Formation have poor to very good TOC value (0,32 – 8,2%), composed by Type I-III of kerogen, and showing immature maturity (338oC – 434oC). Aitutu Formation as Triassic source rocks have poor to very good TOC value (0,06 – 4,16%), composed by Type I-IV of kerogen, and showing early mature to postmature maturity (0,58 – 1,70% Ro). Babulu Formation as the other Triassic source rocks have poor to fair TOC value (0,23 – 0,90%), composed by Type III-IV of kerogen, and showing postmature maturity (1,66% Ro). While Permian source rocks which represented by Atahoc Formation have poor to good TOC value (0,28 – 1,40%), composed by Type IIIIV of kerogen, and showing late mature maturity (1,15 – 1,22% Ro). vi The result of Rock-Eval pyrolysis analysis proved that Aitutu Formation rock samples on Nisnoni and Valas Traverse are labelled as the best rock samples, and will be extracted based on S1 and S2 value in the following step. Furthermore, the biomarker analysis (terpanes and steranes) indicated that the oil seepage samples from Besikama Sub-Basin and Aitutu Formation rock samples are derived from the same source due to both of them are showing the same depositional environment which derived from marine algal components. The 1 dimension basin modeling is performed on Kolbano Anticline Pseudo Well with the new rock sequence input, which has been reconstructed first. The determination of the original rock sequence thickness along with erosion in Cretaceous to Tertiary deposition is very important to be analyzed, to trace the original of rock deposition process before experience uplifting then imbricated as encountered the collision event in Late Miocene. The occurrence of rock deposition process transformation can also influence thermal condition in its deposition, such as vitrinite reflectance value, subsurface temperature, heat flow, etc. Based on basin modeling above, Aitutu Formation currently lied at peak mature to gas window zone, and already had entered early mature at Late Triassic and gas window zone at Middle Jurassic.<p align ="justify">