14 drilling swivel - rgnrgn.hr/.../_private/Krakow_drilling/14_drilling_swivel.pdfmud that is pumped...
Transcript of 14 drilling swivel - rgnrgn.hr/.../_private/Krakow_drilling/14_drilling_swivel.pdfmud that is pumped...
Swivel is a device joining two parts so that one or both can pivot freely.
The rotary drilling swivel, attached directly to the kelly cock, and hence the kelly, allows the drill stem to rotate.
It also has two other functions:
it supports the drill stem, and
it acts as a pressure-sealed passageway for the drilling mud that is pumped into the drill stem.
It consists of two main parts:
(1) non-rotating –cast steel body withload carrying bails, pins and roller bearings, and
(2) rotating –"T" mandrel and wash pipe.
Non-rotating part consists of:
(1) body,
(2) bail,
(3) bonnet,
(4) gooseneck.
Rotating parts are:
(5) stem with “T” beam
(6) main bearing
Upper bonnet base is:
(7) upper thrust bearing.
To center the bonnet in the housing radial lower and upper bearings are mounted (8) i (9).
Sealing is provided through:
fitting in wash pipe packing,
upper fitting for oil seal, and
lower oil seals.
Standpipe and rotary hose
A standpipe conducts drilling fluid from the mud lines coming from the mud pump to the rotary hose.
It includes a gate valve and a pressure gauge, with built-in dampening means for preventing excessive movement.
SWIVEL
ROTARY
HOSE
STAND PIPE
The rotary hose is attached to the standpipe with a special fitting and makes the connection to the gooseneck of the swivel.
It enables the vertical movement of the swivel while circulating mud.
Typical dimensions when manipulation height is 27 m are:
UPPER
WORKING
POSITION
ROTARY HOSE
16,76 m (55ft)
CLEARANCES
0,3048 m (1ft)WORKING
AREA
LOWER
WORKING
POSITION 2,44
m (8ft)
HOOK
MOVEMENT-
24,4 m (80 ft)
STANDPIPE
14,6 m (48 ft)
Z
R
15o
15o
Standpipe length is 14,6 m (48 ft), and rotary hose length is 16,8 m (55 ft).
That enables about 24,4 m (80 ft) vertical movementof the swivel and kelly.
Such length is necessary to allow make up the connection of drill pipe in “mouse" hole, when kelly length is 13,71 m (45 ft) and drill pipe length is 9,144 m (30 ft), with enough reserve to prevent excessive standpipe bending.
Standpipe height is determined from:
Hs=Lr/2+Z
where:
Hs– vertical standpipe height, m
Lr– rotary hose travelling length, m
Z – height from the working area to the gooseneck connection when i lower working position, m
Rotary hose must be flexible and watertight even for high pressures.
It is constructed as:
THREAD
COVER
OUTER SKELETON
(CANVAS)
SKELETON LAYERS
SECONDARY SKELETON
WIRELINE
STRENGTHENING
PRIMARY SKELETON
CANVAS STRENGTHENING
PIPE