Analisis Pore Pressure dan Collapse Pressure Menggunakan Metode Eaton untuk Identifikasi Wellbore Stability di Lapangan "FRE"

E.T.A., Farhan (2025) Analisis Pore Pressure dan Collapse Pressure Menggunakan Metode Eaton untuk Identifikasi Wellbore Stability di Lapangan "FRE". Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini bertujuan untuk memprediksi pore pressure, menentukan distribusi pore pressure, dan mengidentifikasi wellbore stability. Data yang digunakan meliputi logging (gamma ray, sonic, dan density), data tekanan langsung (DST dan LOT), serta data seismik 3D post-stack. Metode Eaton diterapkan untuk estimasi pore pressure dan collapse pressure, yang kemudian divalidasi menggunakan data tekanan langsung. Selain itu, data seismik diolah untuk menghasilkan peta distribusi pore pressure dalam dimensi lateral. Berdasarkan penelitian ini, pore pressure lapangan “FRE” berada pada rentang 0.87 hingga 1.26 sg EMW dengan persebaran pore pressure yang semakin meningkat dan berbanding lurus dengan kedalaman. Overpressure diindikasikan pada nilai pore pressure yang melebihi batas hidrostatik yaitu 1.03 sg EMW yang diakibatkan adanya pembebanan overburden yang menyebabkan kegagalan batuan untuk kompak sehingga tekanan efektif menjadi konstan dan pore pressure meningkat. Terdapat peningkatan tekanan namun tidak signifikan pada area timur lapangan “FRE” sebagai area rendahan. Peningkatan tekanan yang tidak signifikan disebabkan oleh litologi shale yang gagal kompak memiliki interval kedalaman yang tipis yaitu 10-15 meter dengan sisipan batu pasir tipis 4-8 meter. Pada lapangan “FRE” tiga dari lima sumur yaitu FRL-001, FRM-013, dan FRM-014 mengalami wellbore unstability yang diakibatkan oleh mudweight yang tidak dapat menahan collapse pressure pada sumur-sumur tersebut. Pore pressure tinggi dengan litologi yang lemah secara mekanik, dan tekanan lumpur (mudweight) yang tidak mencukupi untuk menahan tegangan formasi.
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This study aims to predict pore pressure, determine pore pressure distribution, and identify wellbore stability. The data used includes logging (gamma ray, sonic, and density), direct pressure data (DST and LOT), and 3D post-stack seismic data. The Eaton method was applied to estimate pore pressure and collapse pressure, which was then validated using direct pressure data. In addition, seismic data was processed to produce a map of pore pressure distribution in the lateral dimension. Based on this study, the pore pressure of the “FRE” field ranges from 0.87 to 1.26 sg EMW, with pore pressure distribution increasing and directly proportional to depth. Overpressure is indicated by pore pressure values exceeding the hydrostatic limit of 1.03 sg EMW, caused by overburden loading that prevents the rock from compacting, resulting in constant effective pressure and increased pore pressure. There is an increase in pressure, though not significant, in the eastern part of the “FRE” field, which is a low-lying area. The insignificant pressure increase is caused by the shale lithology, which fails to compact, having a thin depth interval of 10–15 meters with thin sandstone interbeds of 4–8 meters. In the “FRE” field, three of the five wells, namely FRL-001, FRM-013, and FRM-014, experienced wellbore instability caused by mud weight that could not withstand the collapse pressure in those wells. High pore pressure with mechanically weak lithology and insufficient mud weight to withstand formation stress.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Pore Pressure, Collapse Pressure, Geohazard
Subjects:	Q Science > QE Geology > QE539.2.S4 Seismic models
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geophysics Engineering > 33201-(S1) Undergraduate Thesis
Depositing User:	E.t.a. Farhan
Date Deposited:	21 Jul 2025 06:16
Last Modified:	21 Jul 2025 06:16
URI:	http://repository.its.ac.id/id/eprint/120273

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