Calibration & Testing of Gas Lift Valves & Probe Tester

	Calibration & Testing of Gas Lift Valves & Probe Tester

Calibration & Testing of Gas Lift Valves

GLV test bench is manufactured from heavy duty stainless steel sheet metal, pressure gauges with all stainless steel fittings and valves. Test bench is designed to meet most of the test / calibration requirements of API spec. 11 V1 for GLV's. This is combination of typical sleeve tester, typical encapsulated stem-seat leakage tester and also built-in pressure chamber (ager). Our GLV test bench provides testing facility for following parameters:

1. Charging bellows to specific nitrogen pressure
2. Valve opening pressure
3. Valve closing pressure
4. Valve leakage test
5. Hydrostatic valve test

Tools/Accessories with Test Bench

A) Chamber Valve Removing

Chamber Valve Removing<

B) Pressure Releasing & Charging Tool

Design Parameters

ACT Test Bench is designed in accordance with following design parameters as per API spec. 11 V1.

Design parameters:
1. Valve Size: 1" and 11/2" conventional & retrievable nitrogen charged gas lift valves.
2. System Accuracy: + 100 psi for aging chamber + 5 psi for calibration and charging of gas lift valves.
3. Maximum Bellow Charge: 2000psi
4. Maximum Chamber Hydro test: 5000 psi
5. Valve/Bellow Stabilizing /Storing Capacity: 10 nos (max.)

Constructional Features of GLV Test Bench

There are four sections of test bench as follows:
1. Gauge Section
2. Chamber Section
3. Control Valves Section and
4. Inlet Section

i) Pressure Gauge Section

Used in the test bench as follows:

A) Hydraulic Pressure Gauge:
(Range: 0-10,000 psi)
This pressure gauge shows the pressure in hydraulic pressure chamber (ager).

B) Casing Pressure Gauge:
(Range: 0-2000 psi)
This pressure gauge shows casing pressure in typical sleeve tester and typical encapsulated tester for stemseat leakage test of gas lift valve.

C) Tubing pressure gauge
(Range: 0-2000psi)
To indicate tubing pressure in the glv this pressure gauge is used.

ii) Chamber Section

As shown in above figure there are three testing devices provided in our GLV test bench
A) Hydraulic Pressure Chamber (Ager)
B) Encapsulated Stem-seat Leakage Tester
C) Sleeve Tester

iii) Control Valve Section

There are nine control valves systematically arranged as shown in above figure having specific functions of each one, used to operate test bench for different testings of GLV.

1. Hydraulic Exhaust/Bleed
2. Tubing Pressure Exhaust
3. On/Off For Sleeve, Stem-Seat Leakage
4. Gas Pressure Tubing
5. Leak Test
6. Casing Pressure On
7. For Sleeve Tester
8. Casing Pressure Exhaust
9. Hydraulic Pressure On/Off

iv) Inlet Section

In this section there are three inlet provided with 1/2" NPT for external connection and also two outlets/exhausts provided.

1. N2 Inlet:
From this inlet we can give nitrogen supply upto 2000 psi for GLV leak test and for valve setting & bellow stabilization.

2. Orifice:
Here 1/16" orifice is provided for tubing pressure exhaust.

3. Hydraulic Exhaust:
It is used to exhaust hydraulic pressure in ager.

4) Air Inlet:
Air supply of 100 psi from air hydraulic pump can be applied through this inlet.

5) Water Inlet:
From this inlet we can supply water for inside pressure pump.

Apparatus

Pressure Chamber (Ager)
Tills device is a water filled chamber for maximum 5000 psi pressure. The Gas Lift Valves are inserted into the chamber and subjected to a predetermined external pressure for some length of time and number of cycles.

Test Rack
This equipment is used to set the opening or closing pressure of nitrogen charged valves. There are two types in use: Typical sleeve tester (M-010) and typical encapsulated stem and seat leakage tester (M-011), those are arranged in our test bench very conveniently.

Water Bath
This is a water filled container where several gas lift valves are immersed in the water to bring them to a predetermined controlled temperature. Since most gas lift installations design the GLV set pressure at 16°C, the temperature of the water bath is usually controlled at 16°C.

Probe Tester

Introduction:
The purpose of the gas lift valve probe tester is to determine the relative "stiffness" of a gas lift valve and to determine the maximum available travel of the stem top. When gas pressure is admitted to the tester, it acts on the full area of the valve bellows to lift the stem off the seat. When this pressure increased, the stem tip lifts further from the seat. By using the valve probe tester, an accurate measure of the stem tip travel per pressure increase can be determined and the results tabulated and plotted.

When the pressure is plotted as the ordinate and the stem tip travel as the abscissa, a relatively straight line will be generated for the majority of the stem tip travel. The slope of this line is an indication of the "stiffness" of the valve. The numerical value of the slope is called the bellows assembly load rate (blr) and is measured in psig/inch [kpa/mm]. In this context, the "bellows assembly" includes the bellows and the system which applies a load to hold the valve stem on the seat. The higher the load rate, the "stiffer"the valve and inversely, the lower the lower the load rate, the "softer" the valve.

If the above is done with the same valve, except that opening pressure (dome charge or spring setting) is varied, then the effect of dome charge pressure or spring setting on the bellows assembly load rate can be compared for the same type valve when set for different opening pressures. The bellows assembly load rate is a practical value that can be used to compare different types of valves or when evaluating the same valve under different load conditions and when designing the gas lift installation.

Calibration & Testingof Gas Lift Valves& Probe Tester

Calibration & Testing
of Gas Lift Valves
& Probe Tester