Pendekatan geomekanika dalam analisis kestabilan lubang bor di Lapangan X

DETAIL KOLEKSI

Pendekatan geomekanika dalam analisis kestabilan lubang bor di Lapangan X

Oleh : Jekky LB Sagala

Info Katalog

Penerbit : FTKE - Usakti

Kota Terbit : Jakarta

Tahun Terbit : 2020

Pembimbing 1 : Sugiatmo Kasmungin

Subyek : Drilling

Kata Kunci : geomechanics, drilling, wellbore stability, mud weight, in-situ stress.

Status Posting : Published

Status : Lengkap

File Repositori

No.	Nama File	Hal.	Link
1.	2020_TS_MTP_171011700008_Halaman-Judul.pdf
2.	2020_TS_MTP_171011700008_Lembar-pengesahanan.pdf
3.	2020_TS_MTP_171011700008_Bab-1_Pendahuluan.pdf
4.	2020_TS_MTP_171011700008_Bab-2_Tinjauan-Literarture.pdf
5.	2020_TS_MTP_171011700008_Bab-3_Metode-Logi.pdf
6.	2020_TS_MTP_171011700008_Bab-4_Hasil-dan-Pembahasan.pdf
7.	2020_TS_MTP_171011700008_Bab-5_Kesimpulan-dan-Saran.pdf
8.	2020_TS_MTP_171011700008_Daftar-Pustaka.pdf
9.	2020_TS_MTP_171011700008_Lampiran.pdf

Abstrak
Abstract

P ermasalahan kestabilan lubang bor akan mengakibatkan meningkatnya biaya pengeboran dan berdampak pada jadwal pengeboran. Kestabilan lubang bor dipengaruhi banyak faktor diantaranya tegangan in-situ, tekanan pori, kekuatan batuan, berat jenis lumpur, arah sumur pemboran. Diantara faktor-faktor tersebutada beberapa yang bisa dioptimalkan seperti arah sumur pemboran dan berat jenis lumpur. Penelitian ini bertujuan untuk mengetahui kondisi tekanan pori, regangan in-situ dan kekuatan batuan untuk rekomendasi rentang berat jenis lumpurpemboran berdasarkan atas nilai tekanan pori dan tekanan rekah dan arahpemboran sumur-sumur rencana berdasarkan atas kondisi struktur geologi.Pendekatan secara geomekanika dilakukan terhadap 5 sumur yang telahdilakukan pengeboran. Data sekunder berupa log sumur dan data geologidikumpulkan dan dilakukan perhitungan untuk mendapatkan parametergeomekanika yaitu tekanan pori, tekanan rekah, tekanan vertikal, tekananhorizontal dan kekuatan batuan. Kemudian dilakukan analisis tekanan sumur,analisis tekanan lumpur, analisis kekuatan batuan dan analisis struktur.Hasil penelitian estimasi tekanan pori menunjukkan adanya tekanansubnormal pada kedalaman sekitar 5000-7000 feet dengan gradient tekanansebesar 0,38 psi/feet. Formasi Talang Akar merupakan formasi dengan tekananabnormal dengan rat-rata gradient tekanan sebesar 0,45 psi/feet. Rata-rata gradienttekanan rekah adalah 0,68 psi/feet. Rekomendasi rentang berat jenis lumpur akanstabil pada 8,5 â€“ 9,5 ppg untuk Formasi Cisubuh, Parigi, Cibulakan dan BatuRaja. Rekomendasi rentang berat jenis lumpur untuk Formasi Talang Akar9,4-10,5 ppg. Konfigurasi parameter geomekanik menunjukkan bahwa fault yangterbentuk bersifat transisi antara strike-slip fault ke normal fault (Shmaks â‰ˆ Sv >Shmin). Sedangkan untuk Shmaks azimuth, berdasarkan data world stress mapperkiraan arah Shmaks adalah 025 Â± 20 Â° N. Prediksi kestabilan lubang bordipengaruhi oleh Shmaks yang berarah timur laut-barat daya. Apabila dilakukanpemboran lebih lanjut maka vertical drilling diperkirakan cukup stabil.Directional dan horizontal drilling dapat dilakukan dengan stabil apabilamemotong arah Shmaks dan Shmin.

P roblems with the stability of the wellbore will result in increased drilling costs and have an impact on the drilling schedule. The stability of thewellbore is influenced by factors such as in-situ pressure, pore pressure, rock strength, mud weight, direction of the drilling well. Among these factors, thereare several that can be optimized, such as the direction of the drilling well and the mud weight.This study aims to know the conditions of pore pressure, in-situ stress and rock strength for the recommendation of the range of mud weight based on the pore pressure and fracture pressure and the direction of drilling wells basedon the conditions of the geological structure.The geomechanical approach is carried out on 5 wells that have been drilled. Log data and geological data are collected and calculated to get geomechanical parameters. That is pore pressure, fracture pressure, vertical pressure, horizontal pressure and rock strength. Based on these parameters, well pressure analysis, mud pressure analysis, rock strength analysis, andstructural analysis are performed. Results of the study, it's found that pore pressure estimation shows subnormal pressure at depth of 5000-7000 feet, with average gradient pressure of 0,38 psi/feet. Talang Akar is a formation with abnormal pressure with an average pore pressure gradient of 0.45 psi/feet. The average fracture gradient is 0,68 psi/feet. The prediction of mud weight ranges will be stable at 8.5 - 9.5 ppg for the Cisubuh, Parigi, Cibulakan and Batu Raja Formations. The mud weight prediction for the Talang Akar Formation is 9.4-10.5 ppg. From the results of geomechanical structure analysis, configuration of geomechanical parametersshows that the formed fault is a transition between strike-slip fault to normal fault (Shmaks â‰ˆ Sv> Shmin). Shmaks azimuth, based on world stress map data,the estimated direction of Shmaks is 025 Â± 20 Â° N. Prediction of the stability of the wellbore is influenced by the orientation of the Shmaks withnortheast-southwest direction. If drilling will be carried out in the future, vertical drilling is expect to be quite stable. Directional and horizontal drillingwill be expected stable when cutting the direction of Shmaks and Shmin.