OpenHole Clad (OHC) utilizes a self contained running tool which uses pistons to convert hydraulic pressure into mechanical force for tubular expansion. The OHC system is capable of radially expanding tubulars up to 30% in a wellbore of up to 45° per 100’ deviation.
OHC was originally developed as an enabling technology for re-entry drilling of sidetracked wells, where unstable formations prevented the drilling of the horizontal section. The expanded tubular provides mechanical stability for the wellbore, allowing the operator to continue drilling into the reservoir.
Operational Procedure of the OpenHole Clad system:
-
Make-up expandable casing and tool.
-
Connect work string and RIH to TD, circulate as required.
-
Apply expansion pressure.
-
Release pressure and lower work string to reset tool.
-
Repeat steps 3-4 until the casing is fully expanded.
-
Pull out of hole.
Mohawk’s OHC is a fully integrated system, which includes
the expansion tool, jointed pipe, connectors, external seals, and anchors.
Re-entry formation stabilization
/ Sidetracking
It is common to have sloughing shale above the target
formation. The shale is isolated with
the openhole clad without reducing wellbore diameter.
Zonal Isolation
During drilling of difficult openhole sections, multiple
problem zones can be shut off, allowing the section to be drilled to TD.
Water Shutoff
Faults that allow water ingress into the wellbore in hard
formations can be sequentially patched through the well.
No shoe drillout
Single trip system eliminates junk in the well and reduces
rig time.
Clad through Clad
capability
Unexpanded liner passes through expanded liner enabling
isolation of multiple zones.
Top-down deployment
Provides for contingency operations unavailable with
hydraulic expansion systems.
No pressure is
exerted on the ID of expandable liner
Improves reliability.
No “pop-out”
Eliminates surging of fluid pressure on the formation, which
can collapse liners.
Coiled tubing or
drill pipe deployment
System may be run in either configuration, at the discretion
of the operator.
Tubular
|
Running Tool |
OHC - 312 |
|
45 ft |
|
3.85 in |
|
~1100 lbs |
|
~4 ft |
|
160,000 lbf |
|
10,000 psi |
|
Operational Parameters |
|
|
45o / 100 ft |
|
3,500 - 4,000 psi |
|
3 hrs / 200 ft |
