| Thru-Tubing
Interventions OnLine |
Volume 2,
Number 3 |
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Welcome to 2005’s third quarterly
edition of Thru-Tubing Interventions Online. In this issue, we will again be
taking a closer look at a couple of case histories involving the novel
isolation of a subsea tree utilizing an inflatable solution and a highly
successful coiled tubing Barium Sulphate milling operation performed in the
US Gulf Coast region. We will continue to “entertain” you by enhancing your
oilfield knowledge with an interesting tidbit of oilfield trivia and will
introduce you to our new “What is it?” picture quiz.
Please click here if you received this eNewsletter from a colleague and
wish to subscribe to future issues.
For more information about Thru-Tubing
Interventions, please visit us online at
www.thrutubinginterventions.com. |
|
 What's in your Toolbox?
This section is dedicated to providing information on various products
available within the Thru-Tubing Interventions group.
Hydraulic Release Spears and Overshots
Most types of conventional spears and overshots can be conveyed on coiled
tubing. These include standard basket and spiral-type overshots, kelo
sockets, mousetrap overshots, and releasing spears. However, these types of
tools cannot be released conventionally because coiled tubing cannot be
rotated. If these tools are run on coiled tubing and the fish cannot be
retrieved after latching the overshot, a hydraulic disconnect farther up the
tool string must be activated. This leaves additional tools in the hole. To
avoid this situation, it is advisable to run hydraulic releasing spears and
overshots before running conventional types of spears and overshots with
fishing operations utilizing coiled tubing.
Baker Oil Tools’ Hydraulic Releasing Spears and Overshots are designed
specifically for coiled tubing fishing operations. The overshot is used to
catch either external fishnecks or slick ODs, and the spear is used for
internal fishnecks or slick IDs. Hydraulic Releasing Spears and Overshots
for fishneck profiles are dressed with a collet designed to fit a specific
fishneck type. Overshots and spears designed to catch slick fishnecks are
dressed with a grapple-type collet in the specific catch range size
required.
Key features and advantages
- Flow releasable specifically designed
for coiled tubing conveyance - where no rotation is possible.
- Ability to circulate fluid out of the
end of the tool provides a means of washing debris or fill from the
fishneck to allow for proper latching.
- Collet-style grapple does not get
loaded during jarring operation; grapple section that catches the fish
is in compression when pulling or jarring on the fish.
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Case History: Versatility of Thru-Tubing Inflatable Technology Provides
Isolation Barrier in Xmas Tree
Location: North Sea
The objective of the intervention was to provide a well isolation barrier to
allow for the safe repair of leaking tree valves.
During the initial drifting/survey runs into the well, it was discovered
that the 4-1/2 in. tubing had parted above the downhole safety valve. This
precluded the use of mechanical type plugs. The survey revealed a gap of 32
ft between the tubing. A 3.00 in. OD Thru-Tubing Inflatable (TTI) Crossflow
Retrievable Bridge Plug was selected to set inside the 9-5/8 in., 47lbs/ft
casing between the parted tubing. A fluid reservoir system could not be
deployed with the bridge plug due to a restriction in the available rig up
height; therefore a standard electric wireline running assembly was
utilized. Two unsuccessful attempts to set a bridge plug between the parted
tubing were made. On recovery of these BHA’s to surface, it was evident that
the filters on the Electric Wireline Setting Tool were blocked by what was
later confirmed as iron sulphides. This wellbore borne debris prevented the
tool from functioning correctly.
Discussions between Baker Oil Tools and the client deemed it necessary to
deploy a fluid reservoir system. A full risk assessment was carried out to
highlight any risks while deploying the BHA in an open hole environment. The
new assembly was run in hole and set at a depth of 618 ft mid element. Tests
performed after setting the bridge plug indicated that the flow from the
well had not stopped. Upon recovery of the bridge plug to surface,
indentations down the length of the element indicated that the plug had been
set across the severed control line, allowing fluid bypass. A standard 3.00
in. OD TTI Retrievable Bridge Plug was mobilized to set inside the 4-1/2 in.
tubing stump. With the risk of repeated access to the tubing stump from the
9-5/8 in. casing assessed as being high by the client, Baker Oil Tools
recommended staying attached to the bridge plug throughout the setting
sequence. The BHA was made up with the fluid reservoir system and set at a
depth of 697 ft. No reduction in flow was seen at surface indicating that
the tubing below the plug was leaking. The bridge plug was pull deflated and
recovered to surface.
As a last resort to isolate the well, a 3.00 in. OD TTI Crossflow
Retrievable Bridge Plug dressed with a full cover element was set inside the
bore of the tree, isolating the valve cavities. This final setting provided
the required isolation necessary to allow repairs to the tree wing valves.
The versatility of thru-tubing inflatable technology which allowed one size
of tool to be set in varying diameters allowed the client to achieve the
objectives of this well.
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What is it? Guess the
object pictured! One of our regular
readers, Larry Castleberry of Enterprise Products Company, emailed us with a
suggestion to include a section where we showed a photograph of a small
segment of a tool or similar from our industry in order to try and guess the
full picture. The editors liked this suggestion and offer the following as
our first teaser.
|
Did you guess
what it was?
Click here to
reveal the answer! |
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District Spotlight: Central Asia Thru-Tubing Interventions Team
Location: Aksai, Atyrau and Aktau,
Kazakhstan
Responsibilities:
Thru-Tubing
Interventions,
PIP
Inflatable Packers,
Conventional Fishing,
Casing Exits, and
Remedial and
Stimulation tools.
Operations in the Central Asia Area (Kazakhstan, Uzbekistan and
Turkmenistan) are covered by our offices in Kazakhstan. The main office in
Atyrau consists of Operations Supervisors Alan Fairweather and Jochem
Scherpenisse (back to back) who are responsible for all marketing,
engineering and operational support for the Thru-Tubing Interventions
products and services in the area.
All operations planned specifically for the KPO Integrated Service Contract
(ISC) project are taken care of locally by Cas Lommers and Gary Souness, who
are both based in Aksai as Desk Engineers on the KPO ISC project. Technical
guidance is also provided from the Atyrau office to ensure all fronts are
covered.
Once a solution has been engineered, it is handed over to the respective
workshop for Thru-Tubing Interventions. This is where Workshop Technicians
Nurlan Yeskaliyev, Assyl Izbasev and Deniyar Yessenzhanov under the
supervision of Marat Zherembetov and the below mentioned TST's, are
dedicated to ensuring all tools required for each application are correctly
dressed and tested prior to onward shipment to location.
The Technical Specialist Tools (TST’s) Ruslan Jailauov, Zhenis Berdbekov and
the occasional back-up of Fishing TST Ryan Strachan provide flawless
execution at the well site for all Thru-Tubing Interventions.
Currently, two Product Line Engineers are being trained extensively in order
to relieve the Operations Supervisors of some of their current duties and to
streamline the organization. Dauren Menkeshev will primarily focus on
Conventional Fishing with Berik Zhansat focusing on Thru-Tubing
Interventions.
Together, this team provides high quality Thru-Tubing Interventions
throughout the extensive Central Asia area.
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 Deepwater Intervention
Forum
The inaugural
Deepwater Intervention Forum with the theme of “Managing Assets and
Adding Value” was held at the Moody Gardens Hotel and Conference Center in
Galveston, Texas from July 12th through July 14th. Baker Oil Tools was
pleased at the request of the Technical Program Committee chaired by BP to
present “Thru-Tubing
Inflatable Intervention Tools and Techniques in a Sub Sea Well Environment (2 MB PDF)”.
This link will direct you to view this PowerPoint case history driven
presentation. Along with our participation as presenters to what was
predominantly an operator based audience, BOT exhibited their Deepwater
Sand Control
Systems and sponsored the Forum’s cyber café. The cyber café allowed the
Forum’s delegates to keep in electronic communication with the outside
world.
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 Case History: X-treme®
Workover Motor Outperforms Competitor on Barium Sulphate Scale Milling
Location: Gulf of Mexico
A large independent operator in the Gulf of Mexico encountered a barium
sulphate scale problem in one of their gas wells. A Baker Oil Tools
competitor was selected to perform the cleanout. They attempted to clean out
the well for over 10 days with an average ROP of 11 ft per hour and reached
a final depth of 6377 ft.
The customer requested that Baker Oil Tools carry out the remainder of the
cleanout of the scaled up 2-7/8 in. OD 7.9 lbs/ft tubing to TD. A 1-11/16
in. OD Navi-Drill® X-treme® ‘X’ workover motor dressed
with an F-stator was selected to accommodate for the wellbore temperature of
375 °F. The motor along with a 1.85 in. OD natural diamond mill was run on
1-1/2 in. OD coiled tubing to clean out the scale. Circulating at 37 GPM
with 500-800 lbs WOB the assembly milled scale from 6377 ft to TD at 17,227
ft in one run, with only a few stalls encountered throughout the job which
allowed for continuous on bottom performance. The milling assembly achieved
an ROP of 85 ft/hr during the 70 hour scale milling operation.
Our unique “equidistant” power section technology of the motor delivered
unmatched performance, higher rates of penetration, extended run times and
tolerance to higher temperatures – by successfully completing this demanding
job in one run.
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Did you know? - Quarterly Oilfield Trivia
| Question: |
What traditional
oilfield structure is named for a famous seventeenth century
hangman? |
| |
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| Answer: |
The Derrick;
it was named after Thomas Derrick an English executioner in the
Elizabethan era because of its resemblance to the frame from which a
hangman’s noose hangs. |
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| Papers at a
Glance: Coiled Tubing Milling of a Lower Master Gate Valve
This quarter’s abstract is taken from the paper “Coiled
Tubing Milling of a Lower Master Gate Valve – Equipment Selection and Well
Control Considerations” presented at the 2002 SPE/ICoTA Coiled Tubing
and Well Intervention Roundtable in Aberdeen, Scotland.
The full client co-authored paper can be viewed/downloaded by visiting
International Coiled Tubing Associations (ICoTA)
or click the link above.
Abstract:
This paper examines a unique live well intervention for a major UK North Sea
Operator, in which coiled tubing conveyed milling and thru-tubing inflatable
technologies were combined to restore a producing well to a safe working
condition.
The well had become inaccessible due to a seized lower master gate valve on
the Xmas tree. This prevented access to establish well bore pressure and
perform compliance-required inflow testing of the sub-surface safety valve.
It was believed that the seizure was due to a build up of calcium carbonate
scale. However, previous chemical treatments had proven unsuccessful.
Therefore, a novel solution was performed whereby the gate valve was milled
using a coiled tubing conveyed milling assembly. This was a challenging
milling application because of the complex structure of the gate valve.
Sufficient wellbore access was achieved to allow the setting of thru-tubing
inflatable bridge plugs in the completion string. The bridge plugs acted as
primary barriers, allowing replacement of the Xmas tree, restoring the well
to a safe condition. |
A view down through the Xmas tree of the 4.55 in. ID
milled hole in the lower Master Gate Valve. |
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A “Well’s eye” view from the underside of the milled
out lower Master Gate Valve. |
The full paper discusses the application in detail, with emphasis on pre-job
planning, equipment selection and verification, operational procedures and
lessons learned.
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Ask the Expert
This is where we are asking for your input.
If you have any questions relating to the use of thru-tubing intervention
tools, we would like the opportunity to share both your question and our
answer with your fellow eNewsletter subscribers. We will supply an
appreciation gift to the originator of the question published each quarter.
Submit a question.
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Have a question for
the Thru-Tubing Interventions group after regular Houston business hours?
Contact 281-386-8342 or 281-382-7110 (US) and you'll be connected to an
Applications Engineering Group (AEG) specialist.
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3900 Essex Lane
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