The rig up and down of wireline lubricator assemblies and toolstrings are potentially hazardous activities which may cause serious harm to personnel, damage to plant and equipment and business loss.
The UK’s Health and Safety Executive carried out a review of reported wireline lubricator/toolstring incidents which had occurred in the period 2005/2006, including one fatality. This trend of incidents continued through 2007. Analysis of the data indicated that the incidents were almost exclusively related to dropped toolstrings resulting from pulling the toolstring into the top sheave or stuffing box causing the wire to part. When the dropped toolstring is contained within the well bore/lubricator, there is little risk to personnel.
However, when it is dropped outwith the lubricator or well bore, there is the potential for serious or fatal injury to personnel. The analysis indicated that significant underlying causes of the incidents were failures or inadequacies in:Risk Assessment
Training and Competence
Supervision
Communication
General guidance for the safe conduct of lifting operations is given in the Step Change in Safety publication ‘Lifting and Mechanical Handling’ Guidelines. The rig up/down of wireline lubricators and toolstrings are specific examples of lifting and the Step Change guidelines should be the basis for these operations.
In wireline work, the wireline itself can be used as the lifting/support medium for toolstrings and this has resulted in failed wireline and a consequent dropped object hazard. The aim of this document is to provide guidance specific to wireline operations which complements the general guidance in the ‘Lifting and Mechanical Handling’ guidelines to ensure that the risk of wireline failure and consequent dropped lubricators/toolstrings risks are as low as reasonably practicable.