Petroleum and natural gas industries — Well integrity — Part 1: Life cycle governance
|Publication Date:||1 March 2017|
|ICS Code (Exploratory, drilling and extraction equipment):||75.180.10|
This document is applicable to all wells that are operated by the petroleum and natural gas industry. This document is applicable to any well, or group of wells, regardless of their age, location (including onshore, subsea and offshore wells) or type (e.g. naturally flowing, artificial lift, injection wells).
This document is intended to assist the petroleum and natural gas industry to effectively manage well integrity during the well life cycle by providing:
- minimum requirements to ensure management of well integrity; and - recommendations and techniques that well operators can apply in a scalable manner based on a well's specific risk characteristics.
Assuring well integrity comprises two main building blocks: the first is to ensure well integrity during well design and construction, and the second is to manage well integrity throughout the remaining well life thereafter.
This document addresses each stage of the well life cycle, as defined by the six phases in a) to f), and describes the deliverables between each phase within a Well Integrity Management system.
a) The "Basis of Design Phase" identifies the probable safety and environmental exposure to surface and subsurface hazards and risks that can be encountered during the well life cycle. Once identified, these hazards and risks are assessed such that control methods of design and operation can be developed in subsequent phases of the well life cycle.
b) The "Design Phase" identifies the controls that are to be incorporated into the well design, such that appropriate barriers can be established to manage the identified safety and environmental hazards. The design addresses the expected, or forecasted, changes during the well life cycle and ensures that the required barriers in the well's design are based on risk exposure to people and the environment.
c) The "Construction Phase" defines the required or recommended elements to be constructed (including rework/repair) and verification tasks to be performed in order to achieve the intended design. It addresses any variations from the design which require a revalidation against the identified hazards and risks.
d) The "Operational Phase" defines the requirements or recommendations and methods for managing well integrity during operation.
e) The "Intervention Phase" (including work-over) defines the minimum requirements or recommendations for assessing well barriers prior to, and after, any well intervention that involves breaking the established well barrier containment system.
f) The "Abandonment Phase" defines the requirements or recommendations for permanently abandoning a well.
The six phases of the well life cycle, as defined in this Scope, and their interrelationships, are illustrated in Figure 1 in the Introduction.
This document is not applicable to well control. Well control refers to activities implemented to prevent or mitigate unintentional release of formation fluids from the well to its surroundings during drilling, completion, intervention and well abandonment operations, and involves dynamic elements, i.e. BOPs, mud pumps, mud systems, etc.
This document is not applicable to wellbore integrity, sometimes referred to as "borehole stability". Wellbore integrity is the capacity of the drilled open hole to maintain its shape and remain intact after having been drilled.