Well Intervention Pressure Control Level Two

Well pressure control is the most critical consideration in the planning and performing any well servicing operation.

The awareness of well pressure control in the prevention of injury to personnel, harm to the environment and potential loss of facilities, must be fully appreciated by planning engineers and well site personnel. This appreciation must include a sound knowledge of legislative requirements, completion equipment, pressure control equipment and operating practices and procedures.

‘Well Intervention’ and ‘Workover’ are commonly used terms to describe servicing operations on oil and gas wells and which have, in the past, had many different interpretations.

However, in general, ‘Workover’ describes well service operations on dead wells in which the formation pressure is controlled with hydrostatic pressure. Workover operations are carried out by a drilling rig, workover rig or Hydraulic Workover Unit (HWO) where the Xmas tree is removed from the wellhead and replaced by blow out preventer (BOP) equipment.

‘Well Intervention’ is a term used to describe ‘through-tree’ live well operations during which the well pressure is contained with pressure control equipment. Well Interventions are generally conducted by wireline, coiled tubing or snubbing methods. Snubbing operations are now usually conducted with HWO units.

Well pressure control equipment used by wireline, coiled tubing and snubbing units is so termed as it must control well pressure during live well intervention operations. It significantly differs from BOP systems used on dead well workovers.