CEMENTING PRODUCTS
TECH SPECS
Casing Buoyancy Sub
Reduces drag and friction while running casing in deviated wellbores
Applications
• Running casing in deviated and extended-reach wellbores
• Installing long strings or liner hangers
• Landing casing in wells with high friction forces
Features and Benefits
• Buoyancy forces lift the casing to reduce drag against the formation
while running to setting depth.
• Frangible disk-shear mechanism uses hydrostatic and applied pressure
to break the glass disk.
• Frangible glass disk requires no debris management, removing
obstruction risk to enable passage of additional downhole tools such
as ball seats, float equipment, and toe-initiation subs
• Disk-shear values accommodate the well design and downhole
environment, with opening pressures from 3,000 to 10,000 psi
(20.68 to 68.95 MPa).
• Low-profile design maintains full-bore ID after activation
• Weatherford torque and drag analyses determine optimal sub
placement for best performance.
Tool Description
The Weatherford casing buoyancy sub enhances floatation at the end
of a casing string to enable running through an extended lateral
section. The sub is made up to the casing string above the kickoff
point, creating an air chamber between the sub and the float
equipment at the end of the casing string. This additional buoyancy
decreases drag in the horizontal section while the fluid above the sub
provides weight to assist running the casing to bottom, reducing
trip time.
The casing buoyancy sub can be run in combination with all
completion methods on both long-string and liner-hanger designs and
requires no alterations to the casing or cement operations. The sub is
designed for 4.5- and 5.5-in. production strings and can be threaded
to the customer’s casing specifications. The sub strength
specifications match the host casing. It decreases the need for
rotation to reach TD, reducing requirements for premium-thread
casing. High-pressure and high-temperature options are also available.
weatherford.com
The casing buoyancy sub increases buoyancy at the end
of the casing string to reduce drag while floating casing
into the lateral section of a wellbore.
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in accordance with the terms and conditions set forth in the applicable contract between Weatherford and the client.