(1) | A holder must ensure that a well design is informed by the risk assessment and is constructed, equipped, commissioned, operated, modified, maintained, suspended and decommissioned in a manner that provides for the control of the well at all times and must prevent— |
(a) | the migration of petroleum and other fluids into any other formation except the targeted formation; |
(b) | the pollution of water resources; and |
(c) | risks to health and safety of persons from the well or anything in the well, or in strata to which the well is connected. |
(2) | The final well decommissioning design must be considered at the well planning stage and be included as part of the application for Environmental Authorisation for consideration. |
(3) | The decommissioning design must at least consider the following: |
(a) | The height of cement in annulus outside casing; |
(b) | permeable formations outside the casing that must be covered by cement; |
(c) | cementing casing overlaps; |
(d) | the need for plugs to cover the full diameter of the hole, with only casing within the cement; |
(e) | the type of fluid in annuli above cement; and |
(f) | the difficulty of injecting cement into the annulus. |
(4) | Where technically appropriate and environmentally safe, multi-well pads and horizontal drilling technologies must be considered in order to maximise the spacing between neighbouring wells and to minimise the cumulative surface impact of operations. |
[Regulation 95 inserted by section 2 of Notice No. R. 466 dated 3 June 2015]