Mill Stem Testing

DST allows the testing of layer saturation with different fluids. These allow communication between the productive layer and the tubing.                             

Components of the equipment:

- CE 3 1/8 –is directly screwed to the test string and represents the first component of the equipment where fluid flows in the well.

- ESD- emergency shut-down system – used for shutting down the safety surface valve in case of leaks or damage to the pipes, of errors in operation, of fire or other similar emergency situations.

- nozzle manifold–controls the fluid in the well by reducing the flow pressure, reaching a constant flow before the fluid enters the surface processing equipment.

- two-phase separator–separates, measures and samples the fluids in the well.

- flare pit–designed for the efficient evacuation of gas produced at the surface during testing, which permits prevention of potential pollution issues.

Test packer–mechanically recoverable type, with upper safety cutters hydraulically activated.

Safety joint– offers the possibility to detach the string from above the packer.

Hydraulic jar–used for deblocking stuck pipes.

Pres, Temp measurement device carrier – bottom-hole data gathering device.

Pressure operating testing valve–a ball-valve driven by the annulus pressure.

Reverse flow valve with multiple openings is a circulation valve activated by the annulus pressure equipped with multiple cycle system.

- identification of fluids existing in the layer;

- reservoir pressure, flow rates and temperature measurement;

- sample recovery for lab testing;

The advantages of DST are:      

- reduced testing time (usually 2h flow- 2h build-up, then discharge though another nozzle 2h – 2h build-up etc.);

- no swabbing required (empty tubing is introduced);

- multiple operations are performed during one trip.