ANALYSIS OF THE EFFECT OF AQUIFER ON GAS RESERVOIR USING MATERIAL BALANCE APPLICATION BACHELOR THESIS Ahmad Hasby Ridwanurrahman 12219044 Submitted as partial fulfilment of the requirements for the degree of BACHELOR OF ENGINEERING in Petroleum Engineering study program PETROLEUM ENGINEERING STUDY PROGRAM FACULTY OF MINING AND PETROLEUM ENGINEERING INSTITUT TEKNOLOGI BANDUNG 2023 ANALYSIS OF THE EFFECT OF AQUIFER ON GAS RESERVOIR USING MATERIAL BALANCE APPLICATION BACHELOR THESIS Ahmad Hasby Ridwanurrahman 12219044 Submitted as partial fulfilment of the requirements for the degree of BACHELOR OF ENGINEERING in Petroleum Engineering study program Approved by: Thesis Adviser, Zuher Syihab, S.T, Ph.D. NIP. 197206061999031003 1 ANALYSIS OF THE EFFECT OF AQUIFERS ON GAS RESERVOIR USING MATERIAL BALANCE APPLICATION Ahmad Hasby Ridwanurrahman 1 and Zuher Syihab, S.T., Ph.D. 2 Copyright 2023, Institut Teknologi Bandung Abstract The concept of material balance has been widely used in the field of reservoir engineering to oversee the behaviour and predict the initial hydrocarbon in place of a reservoir. In this study, the author conducted an analysis and investigation of the material balance implementation to observe the effect of the aquifer on reservoir gas. This study focuses on identifying the patterns of change in the gas reservoir performance with different aquifer properties. The analysis was carried out by adopting material balance application by LSU (Louisiana State University), which uses the Fetkovich method for calculating water influx. Sensitivity analysis is furthermore conducted to examine the effects of changing the aquifer parameters, such as the productivity index of the aquifer (,) and the aquifer volume (9AE). The results show that the value of , is inversely proportional to reservoir pressure and aquifer pressure. In contrast, the value of 9AE is directly proportional to reservoir pressure and aquifer pressure. The author also shows that a reservoir can have the same pressure performance from two different aquifers based on the aquifer's , and 9AE values. Keywords: material balance, aquifer effects, gas reservoir, reservoir pressure, aquifer pressure. Sari Konsep material balance telah banyak digunakan dalam bidang teknik reservoir untuk mengamati perilaku dan memprediksi hidrokarbon awal pada reservoir. Dalam penelitian ini, penulis melakukan analisis penerapan material balance untuk melihat pengaruh akuifer terhadap reservoir gas. Studi ini berfokus pada identifikasi pola perubahan kinerja reservoir gas dengan properti akuifer yang berbeda.