SchlumbergerKatamyia BaseTesting department Downhole tools (Drill Stem Test )

By Mohamed Youssef Abdel-mawla

Eng./ Elhassan Ahmed 9 august 2015

Eng./Mohamed Elshreef

Aim: What is drill stem test The tools which used in this test

Objectives: Well testing in general Downhole testing History of drill stem test The tools are used in the test

overview Introduction about Well testing Drill stem test Downhole test tools Testing packers Safety joint hydraulic jar Gauge carriers Pressure test and fill up valves Downhole tester valves Reverse Circulating valves Slip joint Discussion Conclusion

Well testing The aim of well testing is to :1) Prove reservoir potential2) confirm well performance3) improve field productivity The subsystems of well

testing:1) Perforating2) Downhole testing(DST) 3) Subsea well control4) Downhole Pressure Measurement.5) Surface Well Testing.6) Multiphase Well Testing and Monitoring.7) Fluid sampling.

Downhole testing (drill stem test) What drill stem test is A method of gathering(collect) data on

the potential productivity of a reservoir before completion

The main functions of DST are to : Isolate the target zone Control well flow Convey fluid to surface Acquire downhole data History of drill stem test: 1926 first commercial drill stem test. 1927 the Johnston formation testing company. 1933 Johnston bought a pressure recorder. 1956 he was acquired by Schlumberger.

Downhole Test (Drill Stem Test)tools: Testing packers Safety joint hydraulic jar Gauge carriers Pressure test and fill up valves Downhole tester valves Circulating valves Slip joint

1)Testing packer Its function: To isolate the formation

from the annulus. How it works: Pick string up. Apply weight on the

packer(minimum 7 ton for a 7-in. packer)

The tool body moves down and pushes down slips out.

2)Safety joint Its function : It allows quick release of the test string

if the packer or anything below the packer becomes stuck.

How it works: the SJB is disengaged by left-hand

torque. The breakout torque is controlled to 950 ft-lb by a shear pin.

The joint can be engaged by applying weight and rotating slowly to the right.

3)hydraulic jar

Its function: The hydraulic jar is used if a

packer or guns become stuck. How it works: The jar can be used to provide an

upward shock to help pull the tools.

4)Gauge carriers

Its function: to record pressure and temperature Several

times during the test.

How it works: It consists of three main parts sensor ,

electronics, and battery, so the flow passes into the sensor and start to measure pressure and temp.

5)Pressure test and fill up valves There are two types of valves:1)Tubing fill test valve (TFTV)2) Pipe test valve(PTV).They have the same functions Their functions : It provides a method of well control near

the formation. How it works: They are normally run closed and opens

permanently when the disc ruptures and start the testing.

6 )Downhole tester valves:there are three types :1) Intelligent Remote Dual Valve(IRDV)2) Pressure Controller tester valve(PCT)3) port pressure operated reference tool

its function: IRDV combines two multicycle valves: a

tester valve and a circulating valve to provide a high level of flexibility and easy to control the well.

How it works: It is controlled by electronics and uses

hydrostatic pressure as a mechanical energy source to operate downhole tools.

7)Reverse Circulating valve :

Its function: it used to kill the well by reversing

out fluids produced during the test

How it works: It can be opened by applying

annulus pressure to burst rapture disk.

8)Slip joint Its function: The slip joint (SLPJ) is an expansion/contraction

compensating tool. How it works: It moves according the forces affecting as result

of temperature through the stroke

Discussion

Well testing in general what is drill stem test and its function Tools used in the test and how it works

Conclusion

Well testing provides a lot of information about the well Drill stem test is important for controlling the well and getting data There are many tools in DST and technology helps to make the

procedure easier

Thank you