1. Well Head Replacement
Step by step documentation and
guidelines for Thums/Pier J wellhead
removal and replacement.
By: Johnathan Cunningham

2. Wellhead Removal
•Performed casing cut approximately
10-15’ below wellhead.
•Engage casing spear in casing.
•Open load indicator on blocks
•Have welder cut 13 3/8” surface
casing
•Pick up on wellhead with casing spear
to make sure the wellhead is free
(ensure that pack off rams are run in
prior to picking up on wellhead).
•Set wellhead back down and
disengage casing spear
•Wrap a braided sling (NOT a pipe
sling) around wellhead and pull out of
the cellar with the blocks (use block
shackle).
•Remove wellhead and tail out with
forklift
Note: RBP was in the hole as well as
kill fluid below the RBP providing two
forms of well control prior to
performing wellhead removal.

3. 13 3/8” preparation for
repair
•Once wellhead is removed assess the
condition of the 13 3/8” (in some
instances cellar demolition is needed
in order to expose good casing to weld
onto like in the photo to the right).
•Have a UT scan performed on the 13
3/8” to verify where good wall
thickness exists for the new J nipple.
•It is preferable to have 50% wall
thickness to weld onto to make the
necessary repairs.
Note: Cellar floor base is
approximately 2 ft in thickness on
Thums and Pier J.

4. Dressing 13 3/8” for
welding
•Cut and remove both the 20”
conductor pipe and the 13 3/8” to the
desired height.
Note:
Be sure to prevent any concrete or
other foreign material from falling into
the wellbore by removing ANY loose
debris from around the wellbore.
Once the prep has been completed
place a cover over the wellbore.

5. J nipple and well head
installation
•Once the 13 3/8” has been prepped welder can
begin installing the new replacement j nipple.
Note: Be sure to utilize a 13 3/8” collar on the
pin end of the replacement j nipple and thread
on as far as possible (see green collar in photo).
This helps the j nipple retain is roundness when
exposed to heat cycling during the welding
process.
•Once the j nipple has been welded in place
secure make up flange (shown in yellow in the
photo) to the wellhead.
•When making up wellhead ALWAYS rotate to the
left until you feel/hear the wellhead “jump”. This
helps to ensure that the wellhead is started on its
threads properly. If the integrity of the j nipple is
intact through the welding process the wellhead
should thread on with only a few threads still
showing.
Note: If the wellhead will not rotate by hand
beyond a few revolutions back off the wellhead
and attempt to start threads again.
•Make up wellhead with casing tongs to between
2400-2700#.
•Note: It is easiest to orientate the wellhead by
running a stick through the casing valves. This
offers a more accurate reference point for
wellhead alignment.

6. Setting Casing Bowl
Once all remedial work has been performed
on the casing (recovering casing, dressing
casing stub and running on casing bowl with
replacement casing) It is time to set the
casing bowl.
•The casing bowl “swallows” approximately 3
ft of the preexisting casing. This is achieved
by picking up on the casing 50-60k and
dropping it rapidly, allowing the casing bowl
to be worked down onto the stub.
Note: Sometimes rotation is needed in order
to work the casing bowl onto the casing stub.
There is a lip guide on the casing bowl that
helps to align the bowl with the stub.
•Once the casing bowl has bottomed out on
the stub it is necessary to test the bite
achieved by the bowl. This is done by pulling
at increasing weight increments (60k, 80k,
100k). If the bowl is successfully installed the
weight pulled will not bleed off.
Note: Please ensure all personnel are off the
work floor during this testing phase.

7. Rough Cut Casing
Once the casing bowl has been
successfully installed it is time to
remove the BOP assembly. This will
expose the casing that is sticking up
out of the wellhead. At this time we
can prep the casing for the emergency
slips and pack off assembly.
•Have the welder rough cut the casing
to approximately 1 ft above the
wellhead. This will allow for the install
of the emergency slips assembly.
•Remove any burrs and slag from this
cut to allow for the emergency slip
installation.

8. Emergency slip installation
The emergency slips are what hold the
casing in tension. They are usually set at
around 70-80k. This is why it is important
to test the casing bowl in the previous
step to 100k to ensure that the bowl is
set properly.
Note: Break the retaining Allen bolts
loose (4 carbon steel bolts) on the e slips
prior to dropping them over the casing
stub. This will make it easier to remove
them while the slips are inside the
wellhead.
•Slide the emergency slips over the casing
stub. Once the stub has cleared the
wellhead remove the retaining Allen bolts
so the slips can drop down to engage the
casing.
Note: It may be necessary to hammer
the emergency slips downward to get
them located properly inside the
wellbore.

9. Emergency slip Installation
Once the emergency slips are in place
pick up the casing spear and engage
the casing.
•Pull between 70-80k with the casing
spear and slowly return the casing to
neutral weight. Repeating this several
times helps work the emergency slips
down into the wellhead.
•Once the slips are set remove the
casing spear from the casing stub.

10. Continue cutting casing
Perform another rough cut inside the
wellhead to provide more room for the
final cut and dressing of the casing
stub.
•Be sure to leave at least 3 ½” of casing
above the emergency slips.

11. Dressing casing stub
It is now time for the final preperation
of the casing stub for pack off
installation
•Bevel the casing stub in a “V” shape.
•The high side of the bevel should be
located on the inside edge.
•Be sure that any burrs or rough edges
are ground down smoothly to prevent
damage to the O rings located inside
the emergency pack off.

12. Casing stub final dress and
measurements
The final measurement on the dressed
casing stub sticking up from the
emergency slips should be no more
than 3 ¼” and no less than 3”.
•Ideally you want the stub to measure
3 1/8” .
Note: Be sure to make several
measurements around the entire
perimeter of the casing stub to ensure
that the proper height has been
achieved.

13. Pack off installation
After the casing stub has been sized and
dressed it is now time to install the pack off.
•Slide pack off assembly inside of the
wellhead and set it on top of the casing stub.
•Utilize a piece of 4x4 and a sledge hammer
to start the pack off onto the casing stub
•Note:
Grease the inside of the wellhead and casing
stub to reduce the chance of binding while
installing the pack off.
•Once the pack off is started over the stub
use the pack off puller and the weight of the
blocks to “hammer” the pack off onto the
casing stub. In the photo to the right you can
see how the pack off puller top edge is in
alignment with the wellhead. This is a good
indicator that the pack off is fully landed onto
the casing stub.
•Note: Be sure to have the 13 3/8” valve(s)
on the wellhead open to alleviate any
pressure generated by the force applied to
the pack off during installation.

14. Pack off installation
Once the pack off is seated remove the
pack off puller and inspect the depth
the pack off is bottomed out at.
•If the pack off is seated BELOW the
casing rams (see photo) the
installation is complete.
•Run in the pack off rams and packings
to ensure that the proper clearance
has been achieved.
•Remove the plug from the pack off
test port and pressure test to 2500#. If
the installation was successful the
wellhead replacement installation is
complete.
Note:
If you do not achieve a good test and
oil is seen seeping around the casing
stub or emergency pack off removal of
the pack off for inspection is necessary
to inspect the o rings located inside
the pack off assembly.