7/29/2019 seminar kelly bushing
1/16
7/29/2019 seminar kelly bushing
2/16
Kelly Bushing
University of TripoliDepartment of Petroleum Engineering
7/29/2019 seminar kelly bushing
3/16
CONTENTS
Introduction
How does Kelly Bushing work? Fixing (Engagement) of the kelly drive bushing
Types of Kelly bushing
Kelly bushing design
Maintenance
7/29/2019 seminar kelly bushing
4/16
Introduction
The Kelly bushing has inside
diameter profile that matches that
of the Kelly , usually square or
hexagonal
Kelly drive bushing is advise that
is fitted to the rotary table and
which the Kelly passes
Depth measurements are
commonly referenced to the KB,
7/29/2019 seminar kelly bushing
5/16
7/29/2019 seminar kelly bushing
6/16
How does kelly bushing work?
The rotary motion from the rotary table is
transmitted to the bushing through the
pins, and then to the Kelly itself through
the square or hexagonal flat surfaces
between the Kelly and the Kelly bushing.The Kelly then turns the entire drill string
because it is screwed into the top of the
drill string itself.
When the Kelly is disconnected from the
string and set back, the drive bushing is lifted
and set back with it.
7/29/2019 seminar kelly bushing
7/16
Fixing (Engagement) of the kelly drive bushing
Drive Pin
The engagement is accomplished
either :
A) by drive pins fixed into the
bottom of the Kelly bushing fitting
into holes bored into the top of masterbushing
7/29/2019 seminar kelly bushing
8/16
7/29/2019 seminar kelly bushing
9/16
Fixing (Engagement) of the Kelly drive bushing
B) By a square on the
bottom of the Kelly drive
bushing fitting into thecorresponding square recess
of the master bushing
The result of this engagement is
that when the rotary turns the
Kelly and the Kelly bushing turns
the entire drill string
7/29/2019 seminar kelly bushing
10/16
Types of Kelly bushing
Three types of Kelly bushing are available:Heavy, Medium, light-duty
Heavy duty Kelly Bushing
This unit is used for heavy duty drilling operations andhigh torque conditions on off shore as well as on shore
drilling operations.
Medium duty Kelly BushingDesigned for shallow to medium depth applications.
L ight duty Kelly bushing
designed for shallow, slim hole drilling and workover rig
applications
7/29/2019 seminar kelly bushing
11/16
ROLLER KELLY BUSHING
Model Type Drive style Master Bushing Square Kelly size Hex Kelly size
27 HDS Heavy Square 23 - 49 1/2 Inch 3 - 6 3 - 6
27 HDP Pin 23 - 491/2 Inch 3 - 6 3 - 6
20 HDP Pin20 - 22 1/2
inch3 - 6 3 - 6
RTM4 Medium Square 2 - 5 1/4 3 - 4 1/4
20 MDP Pin20 1/2 MSPC and
MDSP2 - 4 1/4 3 - 4 1/4
17 MDP Pin17 1/2 MSPC and
MDSP2 - 4 1/4 3 - 4 1/4
MDS Square17 - 27 1/2
inch2 - 4 1/4 3 - 4 1/4
4 KRVS Square 2 - 5 1/4 3 - 4 1/4
RTS4 Light Square 2 - 4 1/4 3 - 4 1/4
4 KRBM Square 2 - 4 1/4 3 - 4 1/4
7/29/2019 seminar kelly bushing
12/16
Kelly bushing design
The Kelly drive bushing is equipped with rollers that permit the
Kelly to move freely upward or down word either when the rotary
is turning or when it is stationary
The Kelly bushing may be designed to fit either shape of Kellys
(square hexagonal triangular ) or it may be designed to
accommodate either shape by changing rollers to fit
The Kelly bushing may have an optional lock assembly that locks
it into the master bushing , that is especially useful for use with
motion compensators offshore
7/29/2019 seminar kelly bushing
13/16
Rollers of Kelly drive bushing may be either:
single plane roller design
Double plane roller design
7/29/2019 seminar kelly bushing
14/16
Maintenance
1. Lubrication to reduce wear is the most important aspect ofmaintenance , it is done with a grease gun , it can be done
each tour or each day but must not be neglected
2. Keep top nut tight to keep roller pins from working in thebody journal area
3. The bushing regardless of its design type , must be
inspected regularly for wear
4. Parts can be removed and replaced right on the rig floor by
the floor crew under the supervision of the driller
7/29/2019 seminar kelly bushing
15/16
7/29/2019 seminar kelly bushing
16/16