Producing or conducting well intervention operations in adjacent wells during drilling operations is a potentially hazardous situation. In simultaneous drilling/production operations a risk management approach is accepted as being the best way to address the problem.
The following table addresses the most critical activities during drilling operations and identifies the risks, mitigating actions and responsible paths
|
Operation |
Hazard |
Consequences |
Conditions and Controls |
References |
|
|
Drilling 26in hole Drilling 16in hole |
Dropped object
|
Damage to process equipment, release of hydrocarbons, H2S exposure, injury to personnel working in the vicinity. Possible fire or explosion |
Adjacent wells will remain secured with downhole plug SCSSV, BPV Flowline will remain de-pressurised within the collision risk zone (100 ft radius) Area access restriction |
COMPANY Drilling Manual H2S Contingency plan Well Control Manual Contingency Plan and Emergency Well Control Manual |
|
|
Heavy lift Operations over wellbay eg, risers, BOP’s, wellheads and Xmas tree Welding |
Dropped object
|
Damage to process equipment, release of Hydrocarbons, H2S exposure, injury to personnel working in the vicinity |
Closure and de-pressurisation of adjacent wells until lifting operations are complete. (De-pressurisation in this case includes tubing above SCSSV, Xmas tree and flowlines) Permit to work system Area access restricted Pre-job safety meeting P.A. announcement |
Well Control Manual COMPANY Contingency Plan and Emergency Procedure H2S Contingency Plan |
|
|
Perforating Stuck Pipe Fishing |
Premature detonation of explosive charge |
Serious explosion, personnel injury |
Suspension of hot work Area access restriction Radio silence. Local Rules P.A. announcement Stray Current Control |
COMPANY Contingency Plan and Emergency Procedure Radio Silence Standing Instructions |
|
|
Acidizing |
Loss of well control Splash/spill release |
Release of hydrocarbons, H2S, exposure, fire or explosion Injury to personnel |
No hot work on WHJ or cantilever superstructure Closure of adjacent wells Safety clothing Emergency wash stations Area access restriction Wellbay area to be marked area to be marked with Hazard tape. |
Completion Programme COMPANY Contingency Plan and Emergency Procedure H2S Contingency Plan |
|
|
Well testing |
Relief valve on separator pops out extinguishing flare from burner |
Release of hydrocarbons from atmospheric vent boom H2S exposure, fire or explosion |
This operation only permitted with written approval from Drilling Department |
COMPANY Contingency Plans and Emergency Procedure |
|
|
Pressure testing and BOP testing except testing equipment lines |
Failure of mechanical component |
Liquid jet impact, projectiles, injury to personnel |
P.A. announcement. Area defined by components under test to be restricted by use of Hazard tape. Utilisation of certified ‘fit for purpose’ components |
Drilling Manual COMPANY Contingency Plan and Emergency Manual |
|
|
Drilling 12.1/4in hole Running tubing |
Loss of well control |
Release of Hydrocarbons H2S Exposure, possible fire or explosion |
Not hot work on WHJ or cantilever substructure. Should the BOP’s be activated in the event of an emergency then the producing wells should be closed immediately by activating the ESO. |
Drilling Manual COMPANY Contingency Plan and Emergency Procedure H2S Contingency Plan |
|
|
Operations with Radioactive Sources |
Release or exposure to radiation |
Injury of illness to personnel exposed to hazard |
Area access restriction, monitor area Pre-job safety meeting P.A. announcement |
COMPANY Contingency Plan and Emergency Procedure
|
|