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In March 2000, Total installed the first 7-in. RapidConnect junction system in
Ofon 26, a new well located offshore Nigeria, West Africa. The design
called for a cased and cemented main wellbore with a cased and cemented
lateral liner connected to the primary casing, but not cemented at
the junction.[note 2]
The main wellbore targeted two productive zones; a single lateral
tapped a fault-isolated section of the upper zone.
Total individually gravel packed the two producing zones in the
main wellbore, oriented a whipstock using an ICC in the 7-in. primary
casing and then milled an exit window to drill a 6-in. lateral.
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A 4-in. dropoff liner with stand-alone wire-wrapped screens below
an upper 4 1/2-in. temporary liner stabilized the lateral borehole
during cementing operations.
A primary and a backup external casing packer (ECP) isolated the completion interval
before cementing.
After cementing the 4-in. dropoff liner and cleaning out excess cement, the
operator retrieved the upper 4 1/2-in. liner assembly. |
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The junction system was deployed in two runs: first to place a RapidConnect template
across the casing window; and then to insert a tieback liner and seal assembly
into the 4-in. PBR and lock a RapidConnect connector into the template.
Production tubing and completion equipment were connected to the RapidConnect
template; a sliding sleeve adjacent to the junction isolated and selectively
controlled lateral flow. An isolation packer between the lower screen assemblies
in the main wellbore allowed selective production from either interval. |
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2. Ohmer H, Brockman M, Gotlib M and Varathajan P: “Multilateral Junction Connectivity
Discussion and Analysis,” paper SPE 71667, presented at the
SPE Annual Technical Conference and Exhibition, New Orleans,
Louisiana, USA, September 30–October 3, 2001.
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