رضا مصطفوی طباطبایی Reza Mostafavi Tabatabaei, HWO, Hydraulic Work over Solution

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