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ANALISA MASALAH PIPA TERJEPIT PADA TRAYEK 8 ½” DI SUMUR X-01, LAPANGAN JAMBU

Introduction

Analisa masalah pipa terjepit pada trayek 8 ½” di sumur x-01, lapangan jambu. Analisis penyebab pipa terjepit pada trayek 8 ½” di sumur X-01, Lapangan Jambu. Mengungkap differential sticking akibat formasi gamping dan runtuhnya shale. Usaha pembebasan gagal.

Abstract

AbstrakPipa terjepit merupakan salah satu permasalahan yang dapat muncul selama proses pemboran berlangsung. Pipa terjepit dapat menyebabkan permasalahan minor seperti bertambahnya waktu untuk proses pemboran sampai dengan harus dilaksanakanya proses sidetrack atau bahkan sumur harus ditinggalkan. Pada penelitian ini akan dianalisis penyebab dari terjepitnya pipa pemboran pada trayek 8 ½” dan penyebab dari gagalnya usaha pembebasan dari rangkaian pemboran. Aspek yang diteliti pada penelitian ini adalah aspek lithologi formasi (dimana pada aspek ini dapat mengetahui jenis batuan yang menjadi penyebab jepitan pipa). Aspek geometri lubang bor untuk mengetahui apakah pipe terjepit akibat dari key seat. Aspek berikutnya adalah aspek lumpur pemboran dimana akan dianalisis apakah penyebab terjadinya pipa terjepit akibat dari perbedaan tekanan antara lumpur pemboran dan formasi atau karena pengangkatan cutting yang buruk.Berdasarkan hasil penelitian ini trayek 8 ½” ini menembus lapisan gamping yang bersifat permeable dan lapisan shale. Pada kasus ini rangkaian pemboran mengalapi terjepit pada kedalaman 2270 meter (TVD 1895,9 meter). Pipa pemboran terjepit pada formasi batu gamping. Perbedaan tekanan antara lumpur pemboran dan formasi adalah sebesar 1 psia. Berdasarkan aspek lumpur pemboran dan lithologi maka penyebab pipa terjepit adalah differential sticking.Proses pelepasan pipa terjepit gagal dilakukan karena terdapatnya partikel yang menghalangi fluida perendaman mencapai sisi bawah lubang bor, tempat pipa pemboran terjepit. Partikel yang menutupi sisi bawah rangkaian pemboran berasal dari formasi shale yang runtuh akibat dari tekanan hidrostatis lumpur pemboran tidak dapat mengimbangi tekanan collaps.

Review

The submitted paper, "ANALISA MASALAH PIPA TERJEPIT PADA TRAYEK 8 ½” DI SUMUR X-01, LAPANGAN JAMBU," addresses the critically important issue of pipe sticking during drilling operations. This phenomenon is a significant concern in the oil and gas industry, as it can lead to substantial non-productive time, increased operational costs, and in severe cases, necessitate sidetracking or even well abandonment. The authors aim to analyze the root causes of pipe sticking in a specific 8 ½” section of well X-01 in the Jambu field, and further investigate the reasons behind the failure of pipe freeing attempts. The study proposes a comprehensive approach, examining lithological characteristics, wellbore geometry, and drilling fluid properties to identify contributing factors. The research identifies the sticking incident at a measured depth of 2270 meters (TVD 1895.9 meters) within a permeable limestone formation. Based on the analysis of drilling mud properties and lithology, the primary cause of pipe sticking is attributed to differential sticking, with a reported pressure difference of 1 psia between the drilling mud and the formation. This small pressure differential, coupled with the permeable nature of the limestone, is presented as the critical factor. Furthermore, the paper provides a crucial insight into the failed freeing attempts, attributing them to the presence of collapsed shale particles that obstructed the flow of spotting fluids. These particles are thought to have originated from shale formations that collapsed due to insufficient hydrostatic pressure from the drilling mud to counteract the formation's collapse pressure. The paper's strength lies in its focused, practical case study approach to a common and costly drilling problem, offering valuable insights from a real-world scenario. The multi-faceted analysis considering geology and mud properties provides a good framework for problem investigation. However, the abstract could benefit from further elaboration on certain aspects. While differential sticking is identified, the significance of a mere 1 psia pressure difference in causing severe sticking warrants more detailed explanation or context within the full paper, as typically larger overbalances are associated with this phenomenon. Additionally, although wellbore geometry (e.g., key seat) was mentioned as an investigation aspect, its specific role or exclusion in the findings for this case is not explicitly stated in the abstract. For future work or the full paper, it would be beneficial to provide a more in-depth discussion on the drilling parameters (e.g., drilling practices, mud rheology, filter cake quality) that might have exacerbated the issues, and to suggest specific preventative strategies derived directly from these findings.

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