Analisis stuck pipe akibat pack-off dan mud motor back-off di sumur s-13 pada lapangan dg
Penerbit : FTKE - Usakti
Kota Terbit : Jakarta
Tahun Terbit : 2026
Pembimbing 1 : Maman Djumantara
Pembimbing 2 : Andry Prima
Kata Kunci : back-off; mud motor; pack-off; sidetrack; stuck pipe
Status Posting : Published
Status : Lengkap
| No. | Nama File | Hal. | Link |
|---|---|---|---|
| 1. | 2026_SK_STP_071002100011_Halaman-Judul.pdf | ||
| 2. | 2026_SK_STP_071002100011_Surat-Pernyataan-Revisi-Terakhir.pdf | 1 | |
| 3. | 2026_SK_STP_071002100011_Surat-Hasil-Similaritas.pdf | 1 | |
| 4. | 2026_SK_STP_071002100011_Halaman-Pernyataan-Persetujuan-Publikasi-Tugas-Akhir-untuk-Kepentingan-Akademis.pdf | 1 | |
| 5. | 2026_SK_STP_071002100011_Lembar-Pengesahan.pdf | 1 | |
| 6. | 2026_SK_STP_071002100011_Pernyataan-Orisinalitas.pdf | 1 | |
| 7. | 2026_SK_STP_071002100011_Formulir-Persetujuan-Publikasi-Karya-Ilmiah.pdf | 1 | |
| 8. | 2026_SK_STP_071002100011_Bab-1.pdf | ||
| 9. | 2026_SK_STP_071002100011_Bab-2.pdf |
|
|
| 10. | 2026_SK_STP_071002100011_Bab-3.pdf |
|
|
| 11. | 2026_SK_STP_071002100011_Bab-4.pdf |
|
|
| 12. | 2026_SK_STP_071002100011_Bab-5.pdf | ||
| 13. | 2026_SK_STP_071002100011_Daftar-Pustaka.pdf | ||
| 14. | 2026_SK_STP_071002100011_Lampiran.pdf |
|
O Operasi pemboran sumur minyak dan gas bumi, khususnya pada sumurberarah dan kompleks, seringkali dihadapkan pada serangkaian tantanganoperasional yang signifikan. di antara tantangan tersebut, kejadian stuck pipemerupakan salah satu insiden paling merugikan, yang dapat menyebabkan kerugianfinansial substansial, penundaan waktu yang berkepanjangan, dan peningkatanrisiko keselamatan. studi kasus ini didedikasikan untuk mengkaji secara mendalaminsiden stuck pipe kedua yang terjadi pada sumur directional s-13 di lapangan dg.insiden spesifik ini tercatat pada kedalaman 982 m-md dan teridentifikasi sebagaipack-off, sebuah kondisi di mana penumpukan cutting atau material formasiberlebihan di ruang anulus menghambat sirkulasi lumpur dan pergerakan rangkaianbor. gejala awal pack-off ini sangat jelas terdeteksi melalui peningkatan padatekanan pompa dan penurunan drastis pada aliran balik lumpur.untuk mengidentifikasi akar permasalahan di balik insiden pack-off ini,sebuah analisis telah dilakukan. metodologi penelitian melibatkan evaluasiberbagai faktor potensial yang sering menjadi penyebab stuck pipe. analisishidrolika lumpur dan efisiensi transportasi cutting menjadi fokus awal, denganperhitungan cutting carrying index (cci), cutting transport ratio (ctr), dancutting concentration in annulus (cca) dilakukan. angka-angka ini secarakolektif mengindikasikan bahwa efisiensi pengangkatan cutting oleh lumpurpemboran berada pada kondisi yang optimal, sehingga menyingkirkan holecleaning sebagai penyebab utama pack-off dalam kasus ini. selanjutnya, evaluasidogleg severity (dls) di sekitar kedalaman insiden juga mengkonfirmasi bahwanilai dls berada dalam batas yang dapat diterima (di bawah 6°/100 ft), sehinggatidak menjadi pemicu jepitan. analisis differential pressure juga dilakukan melaluiperhitungan tekanan hidrostatik dan tekanan formasi, hasil ini menunjukkan bahwadifferential sticking bukan merupakan faktor signifikan.setelah mengesampingkan faktor-faktor tersebut, fokus analisis beralihpada masalah geomekanika sebagai akar penyebab insiden. diklasifikasikansebagai mechanical sticking yang dipicu oleh keruntuhan formasi atau pack off.kondisi ini disebabkan oleh ketidakseimbangan antara tekanan hidrolik lumpursebesar 9,5 ppg yang ternyata tidak mencukupi untuk menahan collapse pressuredari formasi tersebut. perbandingan mud weight ini dengan pore pressure dan fracture pressure menunjukkan bahwa lumpur berada dalam mud window yangaman, artinya tidak ada indikasi kick atau lost circulation. namun, collapsepressure mengindikasikan bahwa tekanan efektif lumpur pada kedalaman insidenmemang lebih kecil dari collapse pressure formasi. kondisi underbalance relatifini menyebabkan ketidakstabilan dinding lubang bor dan memicu keruntuhanmaterial formasi ke dalam anulus, yang secara tiba-tiba mengakibatkanpenumpukan material dan memicu pack-off.insiden pack-off ini kemudian diperparah oleh terjadinya back-off mudmotor secara tak terantisipasi selama upaya work on pipe (wop) awal untukmembebaskan jepitan ditandai dengan penurunan tekanan pompa, dimana mudmotor sampai dengan bit tertinggal secara permanen tidak diangkat dan berartiditutup secara permanen dengan semen, keputusan strategis berikutnyamelaksanakan operasi sidetrack. meskipun upaya sidetrack pertama mengalamikegagalan akibat interferensi trajektori, sidetrack kedua berhasil dilaksanakandengan sukses, menciptakan jalur lubang baru yang stabil. keberhasilan sidetrackini memungkinkan kelanjutan pemboran sumur s-13 hingga mencapai target yangtelah ditetapkan. studi kasus ini secara tegas menyoroti pentingnya diagnosis akarmasalah yang komprehensif, terutama pada aspek geomekanika, serta urgensiadaptasi strategis dan pengambilan keputusan yang cepat di lapangan untukmeminimalkan risiko dan meningkatkan efisiensi operasi pemboran di masamendatang.
D Drilling operations for oil and gas drilling operations, particularly indirectional and complex wells, are often confronted with a series of significantoperational challenges. among these, stuck pipe incidents are one of the mostdetrimental, potentially leading to substantial financial losses, prolonged delays,and increased safety risks. this case study is dedicated to an in-depth examinationof the second stuck pipe incident that occurred in the directional well s-13 at thedg field. this specific incident was recorded at a depth of 982 m-md and wasidentified as a pack-off—a condition where the excessive accumulation of cuttingsor formation material in the annulus obstructs mud circulation and the movementof the drill string. the initial symptoms of this pack-off were clearly detectedthrough an increase in pump pressure and a drastic decrease in mud return flow.to identify the root cause behind this pack-off incident, a comprehensiveanalysis was conducted. the research methodology involved evaluating variouspotential factors that frequently cause stuck pipe. drilling hydraulics and cuttingstransport efficiency were the initial focus, with calculations performed for thecutting carrying index (cci), cutting transport ratio (ctr), and cuttingconcentration in annulus (cca). these metrics collectively indicated that theefficiency of cuttings removal by the drilling mud was optimal, thereby ruling outhole cleaning as the primary cause of the pack-off in this case. furthermore, anevaluation of dogleg severity (dls) near the incident depth confirmed that dlsvalues remained within acceptable limits (below 6°/100 ft), thus not triggering thejam. differential pressure analysis was also conducted by calculating hydrostaticand formation pressures; the results showed that differential sticking was not asignificant factor.after ruling out these factors, the analytical focus shifted to geomechanicsas the root cause. the incident was classified as mechanical sticking triggered byformation collapse or pack-off. this condition was caused by an imbalance wherethe mud’s hydraulic pressure of 9,5ppg proved insufficient to withstand the collapsepressure of the formation. a comparison of this mud weight against pore pressureand fracture pressure showed that the mud was within a safe mud window,meaning there were no indications of a kick or lost circulation. however, thecollapse pressure analysis indicated that the effective mud pressure at the incidentdepth was indeed lower than the formation’s collapse pressure. this relativeunderbalanced condition caused wellbore instability and triggered the sloughing of formation material into the annulus, resulting in a sudden accumulation of debrisand initiating the pack-off.the pack-off incident was further complicated by an unanticipated back-offof the mud motor during initial work on pipe (wop) attempts to free the string,marked by a drop in pump pressure. consequently, the mud motor and bit werepermanently left downhole and abandoned with cement. the subsequent strategicdecision was to execute a sidetrack operation. although the first sidetrack attemptfailed due to trajectory interference, the second sidetrack was successfullyimplemented, creating a stable new borehole path. the success of this sidetrackallowed for the continuation of drilling well s-13 until it reached its predefinedtargets. this case study strongly highlights the importance of comprehensive rootcause diagnosis, particularly regarding geomechanical aspects, as well as theurgency of strategic adaptation and rapid field decision-making to minimize riskand enhance the efficiency of future drilling operations.