The multiple-opening internally operated reversing valve (MIRV) is a tubing-pressure-operated reclosable reversing valve. An index system enables pressure testing of the tubing string while running in the hole. The MIRV is opened by applying a predetermined number of tubing pressure cycles against the tester valve. When the tool is opened, it can be used to reverse circulate, spot stimulation fluids, or change cushions.
Pumping through the circulating ports at preset pump rates between 0.3 and 1.3 m3/min [2 and 8 bbl/min] closes the tool.
The MIRV can be run in the hole open, which allows the string to fill with mud. After the packer is set, the cushion can be pumped into the string, the MIRV closed, and the test initiated.
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