Electronic Theses and Dissertation

Ketergantungan impor migas Indonesia yang terus meningkat menegaskan
perlunya optimalisasi eksplorasi sumber daya migas domestik, salah satunya
melalui evaluasi kualitas reservoir karbonat Formasi Peutu di Lapangan South
Lhoksukon, Cekungan Sumatra Utara. Penelitian ini bertujuan untuk
mengidentifikasi zona prospek hidrokarbon melalui analisis petrofisika berbasis
data wireline log pada dua sumur, yaitu SLS-D1 dan SLS-D2. Penelitian ini
dilakukan dengan menghitung parameter petrofisika berupa volume shale,
porositas, dan saturasi air dari data wireline log sumur SLS-D1 dan SLS-D2. Data
tersebut kemudian divalidasi dengan data core serta dikalibrasi terhadap data Drill
Stem Test (DST) untuk menentukan nilai cutoff dalam penentuan zona net reservoir
dan net pay. Hasil analisis menunjukkan bahwa SLS-D1 memiliki kualitas reservoir
lebih baik dibandingkan SLS-D2, dengan ketebalan net pay masing-masing 692,25
ft (210,99 m) dan 337,25 ft (102,79 m), serta berhasil diidentifikasi delapan zona
prospek berdasarkan proses lumping. Zona ZP-3 pada SLS-D1 teridentifikasi
sebagai zona paling prospektif dengan volume shale sangat rendah dan saturasi air
rendah, diikuti oleh ZP-6 dan ZP-1, sedangkan ZP-8 pada SLS-D2 tergolong
marginal. Penelitian ini menyimpulkan bahwa Formasi Peutu memiliki potensi
hidrokarbon yang bervariasi antar sumur dengan tiga zona utama yang layak
dijadikan prioritas pengembangan. Untuk penelitian selanjutnya, disarankan
penambahan data core yang lebih lengkap serta integrasi hasil analisis petrofisika
dengan pemodelan reservoir dan data seismik untuk mendukung evaluasi
pengembangan lapangan yang lebih optimal.
Kata Kunci: Cekungan Sumatra Utara, Formasi Peutu, Petrofisika, Net Reservoir,
Net Pay.

The dependence of Indonesia on oil and gas imports highlights the need to optimize domestic hydrocarbon exploration, one of which involves evaluating the carbonate reservoir quality of the Peutu Formation in the South Lhoksukon Field, North Sumatra Basin. This study aims to identify hydrocarbon prospect zones through petrophysical analysis based on wireline log data from two wells, SLS-D1 and SLSD2. This study calculated petrophysical parameters, which are shale volume, porosity, and water saturation, from wireline log data of wells SLS-D1 and SLSD2. These parameters were then validated with core data and calibrated against Drill Stem Test (DST) data to determine cutoff values for defining net reservoir and net pay zones. The result indicates that SLS-D1 exhibits better reservoir quality than SLS-D2, with net pay thicknesses of 692.25 ft (210,99 m) and 337.25 ft(102,79 m) respectively, and eight prospect zones were successfully identified through the lumping process. The Zone of ZP-3 in SLS-D1 was identified as the most prospective zone, characterized by very low shale content and low water saturation, followed by ZP-6 and ZP-1, while ZP-8 in SLS-D2 was classified as marginal. This study concludes that the Peutu Formation exhibits varying hydrocarbon potential between wells, with three main zones, ZP-3, ZP-6 and ZP-1 considered as the suitable priorities for development. For future researches, it is recommended that more comprehensive core data could be available. Therefore, the petrophysical analysis comprehensively can be integrated with reservoir modeling and seismic data to support more optimal field development evaluation. Keywords: North Sumatra Basin, Peutu Formation, Petrophysics, Net Reservoir, Net Pay.