Upload
reza-mostafavi-tabatabaei
View
167
Download
2
Embed Size (px)
Citation preview
Introduction to
Hydraulic Workover Solutions
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
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.
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
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
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.
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
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.
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
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.
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.
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
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
Rotary Table
Hydraulically driven and used for milling and fishing operations
Power Tongs Power tongs – rigged up
in the basket to make up pipe connections