ANALISIS SEKATAN UNTUK MENGIDENTIFIKASI MINYAK YANG TIDAKTERPRODUKSI DI LAPANGAN TANDUN, CEKUNGAN SUMATRA TENGAH

• Main Author: Setiyawan, Hanif
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/77501
• Institution: Institut Teknologi Bandung

The location of study is in Tandun Field which is one of mature oil field operated by Chevron. This field is located about 65 km northwest of Pekanbaru. Tandun field has 21 wells with daily production around 537 BOPD and water cut 96%. The object of study is focused on two reverse fault located on the eastern part of Tandun Field, located in Central Sumatra Basin. AB and BC faults separated the eastern part of the Field Tandun into three blocks. Generally, fault seal analysis performed in oil fields under by Sumatra Light Oil Assets only studied at the exploratory stage and most of fault analyzed is a major fault. Lack of understanding about the characteristics of a small faults at an oil field development stage has an impact on the proposed infill well in the area around the fault and close to the wells with a large production accumulation becomes less attractive because of high risk. The purpose of this study is to determine fault characteristics are as sealing or leaking for fluid flow, so it can be used to identify bypass oil which could not be produced by any existing well. This study was conducted to reduce uncertainty inorder to minimize the failure risk of infill well proposal. Fault seal analysis was performed on two faults, showing that the fault has throw around 70 ft of AB fault and 110ft of BC fault with a dip angle 800 to the west . The results of validation show that both faults act as a sealing fault at SGR value around 27%. Production activities that took place since 1970 did not cause any changes of both faults characteristic. Based on the analysis of reservoir pressure before and after production phase, those faults still be considered as a sealing faults. Throw and highly Vsh (30-65%) cause both faults have the capacity as a sealing for fluid flow in between the different blocks, so that there are some amount of bypass oil reserves that could not be produced by existing wells. Oil reserves estimated around 173 MBO in block B and around 202 MBO in blok C. Those are the total of oil reserves derived from the three reservoirs: BKA, BKB, and BKC. TD # 20 and # 21 wells was drilled based on the result of fault seal analysis and succesfully contributed a significant production of the field, with an additional daily production Tandun about 862 BOPD with watercut 10% (TD # 20) and 256 BOPD with watercut of 20% (TD # 21).