The Compact formation pressure tester (MFT) measures formation fluid pressures for use in permeability and fluid contact determinations. Each tool contains a high-accuracy quartz pressure gauge and a high-precision strain gauge. The MFT is smaller, lighter and easier to operate than conventional tools, providing a faster, safer, more streamlined service. Its unique design automatically centers the body of the tool to give optimal pad application for reliable seals and reduced risk of differential sticking.
A conformable pad seals part of the borehole wall from the mud column, and formation fluid is produced at a programmable rate into a pre-test chamber. Typically an initial fall in pressure is followed by a buildup to the formation value. Permeability can be computed from both the drawdown and buildup behaviors. Multiple tests can be performed at each depth station, and an unlimited number of stations can be tested.
As the MFT arm mechanism closes at the end of each test, the risk of differential sticking is reduced further by the application of a positive fluid pressure from the pad.
Providing measurements for formation pressure and formation-pressure gradient to identify fluid contacts and determine permeability.
Features, Advantages and Benefits
- The MFT can operate on third-party wireline, including monocore cable.
- The slim design of the MFT enables thru-drillpipe conveyance past restrictions as small as 3 in., reducing the risk of nonproductive time associated with key-seated cable.
- The self-centering design reduces the total contact area, thereby reducing the risk of differential tool sticking.
- The MFT generates positive pressure at the pad at the end of each test.
- Setting and closing time in an 8.5-in. borehole is 10 seconds (from one-half to a quarter of the time required for conventional formation testers).
- If tool power is lost, a fail-safe mechanism enables the tool to collapse when overpull is applied.