Drill Stem Test

Drill Stem Test (DST): DST involves the temporary complet...

Drill Stem Test

  • Drill Stem Test (DST):

DST involves the temporary completion of a well to acquire dynamic rate through time, pressure, and fluid property data. The test often indicates how the well will perform when it is subjected to various flow conditions. An analysis is usually performed on the derived data to determine reservoir parameters and characteristics.

Cash flow and production decline may be predicted using these parameters and characteristics. Once cash flow is known, improved drilling, completion, and production decisions can be made on the well and other wells in the field.

Oildata’s DST services provide a safe reliable and efficient means of carrying out Cased Hole Downhole Testing.

The primary function of the DST is to;

  • Isolate the target zone
  • Control well effluent
  • Convey fluid to surface
  • Acquire downhole data

 

The DST tools can be run with Quartz downhole gauges in order to record downhole pressures. Oildata’s DST tool string consists of the following; Multi Cycle Tester Valve

The MCT is one of the key components of downhole testing as it provides the means of opening and closing the well downhole. The MCT valve is a full-opening annulus pressure operated tool. It has the capabilities of taking multiple downhole closure where pipe manipulation is restricted and a full opening string is desired. The MCT valve is also used in creating drawdown and for emergency shut-in of the well.

Retrievable Packer

The retrievable packer provides the very essential function of isolating producing zones during the test therefore ensuring a controlled environment for the test.
The packer has a hookwalled thread that ensures an adequate grip on the casing. It also has a concentric bypass valve which allows a larger bypass flow area. It is easily relocated in multiple zones during a single trip for treating, testing or squeezing.

Multi Cycle Circulating (MCC) Valve

The MCC valve allows for the efficient circulation to be carried while the DST string is downhole. It is;

  • Annulus Pressure Operated, re-closeable valve
  • Allows an unlimited number of pressure cycles
  • Independent operation of the ball valve (to close the string) and the circulating valve.