Drill stem testing TST tubing string tester valve flapper type

Cased hole drill stem testing tools Tubing string testing valve TST flapper type

The tubing string testing (TST) valve is a full-opening valve used to pressure test the workstring while running in the hole.  The valve is operated after it is stung into a permanent packer or a retrievable packer is set. The TST valve requires a differential pressure between the annulus and the tubing to shear. The TST valve can also be used for pip flexing if it is run below an annulus pressure-responsive circulating valve.

In downhole operation, the valve can not be closed after open.

When running in the hole, the tester valve must run in downhole in opening condition, after string testing finished, increasing annulus pressure made the flapper valve open, also can process closing well operation for tester valve(pressure-responsive valve).

The TST valve consists of:   

• Flapper valve and spring. 

• shear pin section 

• locking dogs 

Features and benefits

Flapper valve requires only 4psi to open

Testing string can be pressure-tested as many times as required as it is run in the hole.

Valve shear rating can be pre-determined at 500psi increments.

Valve can also be used for pipe flexing.

Operation

When the TST flapper valve opens, it allows the workstring to fill up. The shear pins hold the mandrel in place. The workstring can be pressure-tested as many times as required as it is run in the hole. While the workstring is stationary, a spring keeps the flapper valve closed. After the workstring pressure test is complete, the tool is sheared when annulus pressure is applied to the predetermined shear pin rating. 

(The shear rating can be adjusted in 500 psi increments to shear from 500 to 60000psi differential). When the pins shear, the mandrel moves up and pushes the flapper open, allowing the locking dogs to engage. The tool is then fully open. The tool works on differential pressure between annulus and tubing. Failure to shear initially on application of annulus pressure is not critical. The process of drawing the well down also creates a pressure differential that helps the tool shear. When used for pipe flexing, the TST valve is run below an annulus pressure responsive circulating valve, such as the RD circulating  valve.  The string is pressured up against the flapper valve as many times as required. The circulating valve is sheared after flexingoperations are complete, and the workstring is pulled out dry. 

ZZ TOP OIL TOOLS is the professional manufacturer for the drill stem testing tools and surface testing equipment. All the DST tools are conformed with NACE MR 0175 with traceability,and the DST tools can be worked in H2S & CO2 above 175 F and full H2S, also with the skilled and experienced engineers, we can design the drill stem testing tools as per customer's well condition. Moreover, we supply the training in our factory and operation instruction at the well site. The DST tools are exported to USA, Colombia, India, Pakistan, Iran, Brazil etc. and enjoy the good reputation from the customers.

To shorten the delivery time, we proceeded the DST Tools in stock:

Packer,circualting valve,select tester valve,APR N-valve,OMNI valve,Hydraulic Jar,Tubing string tester

1. Full bore Packer, 7" Casing, working pressure 70Mpa, Working Temperature 400F, Connection: IF, 4set

2. Tester valve, 5", Working pressure 105Mpa, Working temperature 400F, Connection CAS. BXP, 4 sets

3. Hydraulic Jar,5", Working pressure 105Mpa, Working temperature 400F, Connection CAS. BXP, 4sets

4. Rupture disk Circulating valve, 5", Working pressure 105Mpa, Working temperature 400F, Connection CAS. BXP, 4sets

5. Flowhead (surface test tree), 3 1/16", working pressure 70 Mpa. 1set

Drill stem testing TST tubing string tester valve flapper type

Cased hole drill stem testing tools Tubing string testing valve TST flapper type