بهینه سازی عملیات‌های حفاری از طریق مدیریت ریسک حفاری و طراحی مسیر چاه

نوع مقاله : مقاله پژوهشی

نویسندگان

1 پژوهشکده بالادستی نفت شریف

2 دانشگاه صنعتی شریف

3 دانشگاه صنعت نفت

چکیده

تلاش در جهت مدیریت ریسک­های حفاری می­تواند دستاوردهای قابل توجهی در جهتِ به حداقل رساندن هزینه­­ها و بهبود سرعت حفاری داشته باشد. هدف این مقاله بیان نحوه صحیح اجرای مراحل مدیریت ریسک حفاری در جهت بهینه­سازی عملیات است. شناسایی، ارزیابی و اولویت­­بندی مراحلی هستند که منجر به تشکیل ریسک فرم جامع حفاری می­شوند. در ریسک فرم جامع حفاری تمام ریسک­ها در کنار سازند محل وقوع، احتمال وقوع و شدّت تأثیر آن­ها به ترتیبِ ضریب چالش مرتب شده­اند. در مرحله­ی برنامه­ریزی، تمرکز این مطالعه بر روی جلوگیری از وقوع ریسک­ها در حفاری­های آینده است. به عنوان یک روش جدید در جهت دور ماندن از وقوع ریسک، با کمک گرفتن از روش زمین آماری کریجینگ، یک نقشه سه بُعدی از سرعت حفاری در تمام میدان تشکیل شد که در آن میزان سرعت حفاری در نقاط مختلف میدان و در عمق­های مختلف زمین نشان داده می­شود. این نقشه با نشان دادن تفاوت سرعت در نقاط مختلف، در حالی که به صورت ضمنی نقاط پُر ریسک و کم ریسک را نشان می­دهد، می­تواند برای تعیین مسیر بهینه چاه در حفاری­های آینده مورد استفاده قرار گیرد.

کلیدواژه‌ها


عنوان مقاله [English]

Improving drilling speed and cost reduction through risk management and well-trajectory design

نویسندگان [English]

  • Ali Tahmasebi 1
  • Shahab Ayatollahi 2
  • Nader Dashti 3
  • Riyaz Kharrat 3
1 Sharif Upstream Petroleum Research Institute
2 Sharif University of Technology
3 Petroleum University of Technology
چکیده [English]

Summary
In this paper, in order to minimize drilling costs, it is attempted to offer a way to reduce future drilling risks through analyzing past drilling. Risk management steps are implemented for the past drillings in one of the Iranian oil fields. Before risks can be managed, they must be identified, and they must be identified before they become problems adversely affecting the project. The analysis is the conversion of risk data into risk decision-making information. The most common risks are identified and evaluated in severity and probability.  Evaluated risks are classified into five categories of tolerable (T), low (L), medium (M), high (H) and intolerable (IN). A risk number is assigned to each of these categories that are prioritized based on their risk number. Finally, a consolidated list of priorities of risks is created. Planning turns risk information into decisions and actions for both the present and future. As a new method for risk aversion planning, a three-dimensional (3D) map of the geology formation in order to specify the best future well path, is designed. This shows the high risk and low risk point in the formations that drilling bit will be passed from. Drilling can be carried out in a way that there are tolerable risks.Drilling speed for the formations has been defined as a rock property (same porosity or permeability) and propagated into formations based on the past drilling data with simple kriging method. This study attempts to through an analyzing past drilling from two aspects of time and cost in one of Iranian oil fields as a case study, and then, by implementing risk managements to offer a way to reduce the risk of future drilling in the oil field.
  Introduction
Drilling sector is one of the most important and most challenging parts of both offshore and onshore oil fields development. A great part of expenses in this development is allocated to the drilling sector. Reduction or minimization of drilling costs is an important step in order to minimize development costs. Drilling costs have become extensively  large in difficult reservoirs with complex drillings so that several companies usually will make groups to share the financial risk (Bourgoyne et. al., 1986). The drilling time that is wasted as the losses such as the loss of drilling equipment and fluids, and the loss of drilling process continuity, is considered as non-productive time (NPT) (Aldred et. al., 1999). Drilling risk management can reduce and even remove these risks and their effects.

کلیدواژه‌ها [English]

  • Drilling management
  • NPT
  • ROP
  • Risk Management
  • well path
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