MEC&F Expert Engineers : WHAT IS HYDRAULIC WORK OVER (HWO) AT OIL AND GAS WELLS?

Sunday, November 23, 2014

WHAT IS HYDRAULIC WORK OVER (HWO) AT OIL AND GAS WELLS?



WHAT IS Hydraulic Work Over (HWO) AT OIL AND GAS WELLS?

Hydraulic Workover is a versatile, cost-saving and safe technique for repair- and remedial work on all types of wells.



Hydraulic Workover may include:

     Completing or re-completing wells
     Installation of ESP pumps
     Tubing conveyed perforations
     Installation of liners and sand screens
     Repair of down hole safety valves (scsssv)
     Drilling over small distances
     Fishing/ (production) Packer Milling operations
     Casing milling, milling bridge plugs, etc.
     Casing repairs
     Well Clean outs / Cleaning, Stimulations
     Cementing
     Abandonments

Why HWO?
Hydraulic Workover is a well intervention technique which can be used to install or remove tubular in- or out of dead wells.  "Dead" well means that the well has zero surface pressure and has a heavy fluid or mud in the wellbore, or is not capable of sustaining natural flow.



Advantages of Hydraulic Workover
A HWO unit can cover the same working envelope as a workover rig but has advantages over conventional rigs or hoists for certain applications, such as:

     Small and flexible footprint
     Small environmental impact
     It is quickly and easily mobilized to offshore platforms
     It is quickly and easily mobilized to remote land wells
     Costs efficient
     Perfect control over the workstring (tubular)
     Custom Rig-up configuration / Modular approach



Hydraulic Power
The HWO unit (Hydraulic Workover Unit) utilizes hydraulic cylinders to lift the tubular in- or out of the well.  The use of hydraulic cylinders allows perfect control over tubular movements and eliminates the use of a large mast construction which is present on conventional drilling rigs.
Hydraulic cylinders can generate large pull and push forces and give the HWO unit a small footprint and layout. These properties are especially beneficial for offshore operations where space is limited and where weather conditions can be harsh.  In general is the running speed of a HWO unit lower than that of conventional workover rig.