Topside Installation by

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Topside Installationby

• sendit
• Patents awarded
• sendit, llc
  
  Tel [phone]
• One Greenway Plaza
  
  sendit_at_twindog.com
• PO Box 42484
• Houston, TX 77242-2484

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Scope of Activities

• Conceptual Constructability
• Engineering
• Procedures shown herein demonstrate the
  application of
• this float-over method with a variety of
  substructure designs

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One design for several substructures
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FeatureStructural part of topside is designed
as a floating component using shipbuilding
techniques for In-place Service and Construction
Weather Criteria
Load located above support of X-Truss reduces
loadings
Support location is variable
Height of X-Truss
Full height areas for facilities
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Recessed Support Located Between Bulkheads
Bulkhead/X-Truss/Skid beam
Support Yoke Mating interface located above
water surface
Recess
Bottom of Topside
Leg attached to substructure
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Feature Areas can include multiple elevations
and higher sides
Full height area
Multi level areas
Outside bulkhead protects from environment
Height of X-Truss
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Feature
Fewer topside elevations reduces the wind catch
area and the center of gravity
One versus two level topside reduces the
projected wind catch area approximately 30
percent. Foot print of one elevation Foot print
of equal area in two elevations
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FeatureTopside fabricated, transported,
installed and commissioned as a fully assembled
unit minimizing the completion work to be
performed offshore
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Feature

• Buoyancy of the in-place design of the
  substructure
• is utilized for the installation operations
• Installation can be performed with tugs

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Feature

• The method facilitates installation during
  more severe
• weather conditions as impact forces are
  reduced

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Basic Approach Motion Compensating and Lifting
Floating topside
Leg attached to substructure
Topside and substructure respond in unison to
motions as one unit
Substructure acts as an increasingly stiffer
spring when deballasted lifting the topside to
the final elevation
Floating topside positioned above the submerged
substructure. Lifting means attached to the
substructure from the topside
Substructure lifted until in contact with
floating topside inside recesses
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Applications

• The concept is suitable for platforms using
• substructures of the following designs
• Catenary Anchor Leg Mooring
• Tension Leg
• Seabed support

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Basic Approach with Floating platforms
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Substructures installed separately from the
topside
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Vessels supporting substructure at depth
required for clearance to underside of topside.
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Topside transported to the installation site by
towing or Heavy Lift Transport Vessel
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Winch lines from vessels positioning the
topside
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Lifting means connected to the substructure
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Substructure lifted from the topside until in
contact inside recesses
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Topside raised to the final elevation by
deballasting the substructure
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Same procedure for SPAR and SCF
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Drilling rig can be used for lifting of
substructure
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Installation of topside using telescoping
legsMultiple number of legs compensate for
motions individually facilitating installation
under more severe sea conditions
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Installation of topside using single telescoping
legSingle leg compensates for motions
facilitating installation under more severe sea
conditions
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Basic Approach with Seabed Supported
Platforms
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Installation of topside on seabed supported
substructureTelescoping legs compensate
individually for motions facilitating
installation under more severe conditions
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Seabed supported substructure in arctic
environment Single column breaks ice
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Compliant Tower
Cylindrical moon pool in lieu of conductors Moon
pool used as a plunger for installation of the
topside as a single unit After lowering, the
moon pool contains all wells with the possibility
for adding pipeline risers and pull-tubes Wells
drilled and completed with dry trees from the
topside with the alternative of only the
production risers extending from the seabed
similar to designs used with TLP and SPAR
platforms A moon pool that extends to the
seabed can be be used for supporting loads that
otherwise would transfer through the substructure

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Advantages

• A topside that is installed as a single unit
  reduces fabrication, transportation, assembly,
  completion and commissioning costs with schedule
  advantages

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Advantages

• A topside that is installed as a single unit
  reduces fabrication, transportation, assembly,
  completion and commissioning costs with schedule
  advantages
• Buoyancy capacity of the in-place design is
  utilized in the installation operation
  alleviating the cost for temporary buoyancy
  elements

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Advantages

• A topside that is installed as a single unit
  reduces fabrication, transportation, assembly,
  completion and commissioning costs with schedule
  advantages
• Buoyancy capacity of the in-place design is
  utilized in the installation operation
  alleviating the cost for temporary buoyancy
  elements
• Large complement of tugs are available reducing
  scheduling constraints in comparison with
  alternative methods of installation

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Advantages

• A topside that is installed as a single unit
  reduces fabrication, transportation, assembly,
  completion and commissioning costs with schedule
  advantages
• Buoyancy capacity of the in-place design is
  utilized in the installation operation
  alleviating the cost for temporary buoyancy
  elements
• Large complement of tugs are available reducing
  scheduling constraints in comparison with
  alternative methods of installation
• Lesser sensitivity to weather conditions during
  the installation phase reduces weather stand by
  exposure

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Advantages

• A topside that is installed as a single unit
  reduces fabrication, transportation, assembly,
  completion and commissioning costs with schedule
  advantages
• Buoyancy capacity of the in-place design is
  utilized in the installation operation
  alleviating the cost for temporary buoyancy
  elements
• Large complement of tugs are available reducing
  scheduling constraints in comparison with
  alternative methods of installation
• Lesser sensitivity to weather conditions during
  the installation phase reduces weather stand by
  exposure
• The concept provides a larger area per elevation,
  which reduces the wind catch area and center of
  gravity resulting in lesser overturning moment

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Frequently Made Comment

• There is a weight penalty associated with
  using a
• floating topside
• The following slides clarify the result from the
  order of magnitude comparison between a single
  level and a two level topside on a four leg TLP.
• In addition to the results found in the
  comparison the lesser wind catch area and lower
  center of gravity results in a reduction in the
  requirement for the substructure and the station
  keeping designs

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Comparison of Topside Weights Four Column TLP

• Floating topside
  Compared
• Primary steel 6,100 5,000
• Secondary steel 800 800
• Tertiary steel 1,200 1,200
• Facilities 5,000 5,500
• DES Skid truss 1,600 1,600
• DSM Primary steel 0 1,200
• DSM Other 700 700
• Total weight 15,400 mt 16,000 mt
• Openings cut in hull after installation
• Living quarters and tanks built into the
  barge
• DSM primary steel included in the Floating
  topside weight

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X-Truss (skid beams) supported directly over
columns Wells located inside the bulkheads
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Drilling Equipment Set, Skid Base located on
truss Facilities, living quarters and
storage on decks areas Tanks located inside truss
above supports
DES
LQ
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Deck layout
Production equipment and storage areas
Skid beams
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Frequently Made Comment

• There is a weight penalty associated with
  using a
• floating topside
• We are reluctant to use new technology such as
  submerging the substructure under the water
  surface

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Project Reference Bottom section of the Cognac
platform afloat Lowered to the seabed in 1025
feet water depth
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Vessels supporting a submerged substructure is
mature technology
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Frequently Made Comment

• There is a weight penalty associated with
  using a
• floating topside
• We are reluctant to use new technology such as
  submerging the substructure under the water
  surface
• Submerging the substructure increases the design
  hydrostatic head with resulting higher
  fabrication cost

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Substructures are designed for survival
conditionsSubmergence during installation is a
temporary load case performed during less severe
conditions
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Frequently Made Comment

• There is a weight penalty associated with
  using a
• floating topside
• We are reluctant to use new technology such as
  submerging the substructure under the water
  surface
• Submerging the substructure increases the design
  hydrostatic head with resulting higher
  fabrication cost
• It is possible to transport a fully assembled
  platform with a heavy lift transport vessel for
  final outfitting and commissioning in the
  vicinity of the installation location

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Reduction of fatigue life is more extensive when
transporting larger objects
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All development phases including final
outfitting and towing to the installation site
have to consider weather criteria such as
hurricanes
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Two-part installation reduces the risk
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sendit

• We thank you for the attention and are looking
  forward
• towards participating in your projects
• Look for further developments at
• www.twindog.com