Reduce toolstring complexity and simplify rig up
The ACTive MHA assembly is a compact form of all the standard bottomhole contingency components typically run for every CT operation, which minimizes toolstring complexity and simplifies rig-up. It’s designed to withstand the heavy demands of milling, jarring, impact hammers, perforating, and CT applications that involve high shock or vibration loading.
The ACTive MHA assembly comprises the following main components:
- Optical bulkheads—Pin and socket bulkheads allow the ACTive MHA
assembly to be placed between the CT head and the ACTive services
BHA. Note that this reduces the system optical margin by adding one
more flat polished connection.
- Drain port—A drain port allows for fluid trapped above the check valves
to be removed before the ACTive MHA assembly is removed from the CT
head, helping to ensure that fiber connections are not contaminated and
that environmental and spill policies are followed.
- Check valves—Dual-flapper check valves provide a double barrier to
prevent wellbore fluid from returning up the CT to the surface.
- Hydraulic disconnect—A piston in the ACTive MHA assembly supports
lugs that connect the upper and lower sections. A ball pumped from
surface is used to shift the piston, which drops the lugs and allows the
tool to separate. An external JDC-style fishing profile is left exposed
after the upper section is retrieved.
- Circulation port—The ACTive MHA assembly allows for a burst disc
to be installed below the disconnect piston. In the event that there is
no circulation through the toolstring, the burst disc can be ruptured to
allow flow to the annulus to pump down the disconnect ball. If
the burst disc is not needed, it can be replaced with a blank plug.
Lengthen CT toolstrings
As ACTive services toolstrings have grown in length due to the addition
of new measurements, it is not always accepted to place a conventional
MHA below the ACTive services toolstring. The 2 1/8-in ACTive MHA
assembly provides standard contingency features at the top of the ACTive
services toolstring.
