Hydraulic workover (HWO) involves running and pulling tubulars into wells under pressure using a hydraulic workover unit. HWO has been used since the 1920s and offers benefits like keeping wells producing during work by avoiding killing the well. A HWO unit consists of a work basket, hydraulic jack, slips, rotary table, and other components to move tubulars into the well while maintaining well control. HWO can be used for various applications like routine or emergency well work as a cost-effective alternative to wireline or coiled tubing.

1. Introduction to
Hydraulic Workover Solutions

2. History of Hydraulic Workover
Hydraulic Workover “HWO” is a well
workover performed using a hydraulic
workover (snubbing) unit to run and/or pull
tubulars – with or without surface pressure
present on the wellhead.
Hydraulic Workover Techniques in use since
1920’s
First Hydraulic Units developed in 1959

3. Definition of Snubbing
Snubbing is the process of running and pulling tubing, drillpipe, or casing with
surface pressure present on the wellhead.
Snubbing also describes a force-balance condition (or the “pipe-light” condition)
where an external force is required to prevent the workstring from being force out
of the hole.
In some situations, Hydraulic Workover (HWO) may also be used to trip tubulars into
and out of wells with no existing or anticipated surface pressure.

4. Reasons for Utilizing HWO
 When CT or Wireline is incapable of performing the task
 When reservoir damage is anticipated
 When platform infrastructure is inadequate
 Cost considerations
 HPHT/Critical Deviation - Emergency Work

5. Benefits of HWO Services
 Operations are completed while under pressure, well does not need to be
killed.
 Reduces Costs by eliminating need for kill fluids
 Eliminates risk of damaging producing formation with kill fluids
 Compact size, mobile, fast rig up/rig down
 Reduces overall costs
 Well remains in production
 Versatile - Rotational ability allows drilling/milling

6. Misconceptions for Using HWO Services
Ø For “Last Ditch” effort on problem/critical wells in emergency
situations.
 Can be used for all applications - routine or critical.
Ø For only “live” well remedial services.
 Can be used on “live” or “dead” wells.
Ø For only high pressure applications.
 Can be used on low pressure applications as well.
Ø Very expensive.
 Can be a very cost effective tool.

7. Safety Considerations For HWO
 Thorough Pre-Job Planning
 Required Employee Training & PPE
 Perform Preventive Maintenance Service to Equipment
 Location Safety Meetings Conducted
 Location Standards Adhered To
 Engineering Calculations Considered
 Location Layout of Equipment

8. Hydraulic Workover Unit
 Conventional Stand Alone Hydraulic Workover
units are self contained operating systems
consisting of modular equipment groups that
are easily transported and rigged up.

9. Components of HWO Unit
 Work Basket and control panel
 Hydraulic Jack assembly
 Traveling Slips
 Rotary Table
 Guide Tubes
 Stationary Slips
 Hydraulic power pack, accessories, and
hydraulic hoses
 Circulating swivel, kelly hose, and pumps
 BOP Stack

10. Workbasket
 The workbasket, located on top of
the jack, is used as a work
platform. Controls for the jack,
traveling and stationary slips,
BOPs, and counterbalance are
located in the work basket.

11. Control Panel
 Typically there are two control panels,
one for the jack operator and one for
the helper. The operator controls the
vertical movement of the jack and the
operation of the slips. The helper
operates a counterbalance that lifts
and lowers joints of pipe to and from the
basket.

12. Traveling and Stationary slips
Traveling Slips – located on the
traveling assembly, which moves
vertically up and down as the
cylinder rods are extended and
retracted
Stationary Slips – attached to the
base of the jack and are used to
hold the pipe while the traveling
slips are not engaged

13. Hydraulic Jack Assembly
 Hydraulic jack – one or more hydraulic
cylinders configured to move the pipe
into and out of the hole
 Guide Tube – placed in the bore of the
jack to provide the lateral support
necessary to prevent buckling of the
workstring

14. Rotary Table
 Hydraulically driven
and used for milling
and fishing operations

15. Power Tongs
 Power tongs – rigged up
in the basket to make up
pipe connections