Gas Lift Overview and GLToy User Guide

OVERVIEW

Gas Lift ^GLtoy

(by: Burney Waring) Tasks

GAS LIFT

GLTOY (BY: BURNEY WARING)

Injection Rate Casing Head Pressure

Tubing Head Pressure

Wellhead Choke Size

Production Rate

Depth vs Press.

Graph.:

• Blue Line = CHP

• Black Line = FTP Lift Gas

Performance Curve

Inflow

Performance Relationship (IPR) Curve

Tugas Gas Lift – Kerja Kelompok

▪ Maximum jumlah anggota per kelompok adalah 4 (empat) orang. Kombinasi: 3 men 1 woman, 2 men 2 women, 1 man 3 women.

▪ Beri nama kelompoknya.

▪ Minimum Viable Product: Satu (1) Laporan Observasi berdasarkan GLToy untuk melakukan Tasks yang ditentukan.

▪ Batas pengumpulan laporan untuk PE6A adalah jam 12:00 malam tanggal 31 Mei 2024.

▪ Batas pengumpulan laporan untuk PE6B adalah jam 12:00 malam tanggal 1 Juni 2024.

Task 1: Unload Well without Cutting Out Valve(s) at 300 Mscf/d

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Objective: successfully unload the well without cutting out valves and get the well operating with 300 Mscf/d gas lift rates

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Show the message “Unloading too fast!”

◦ You have violated the API's [API RP 11V5] recommended unloading limit of 5 psi/minute up to a CHP of 300 psi and 10 psi/minute thereafter.

◦ The idea is that unloading too fast will cut out unloading valves. High velocity liquid will simply erode the metal of the valve, and the parts there are very small.

◦ It should take a minimum of 2 hours and 10 minutes to get to 1000 psi (60 minutes to get to 300 psi, and 70 more minutes to get to 1000 psi).

Task 1: Continued

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Note down completion brine rates.

◦ In the beginning you may have kept them below 200 blpd, but after the gas injection

goes into the top valve and the pressure in the tubing falls, the rate goes up dramatically with the differential pressure across the valves.

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If you want to try again, click the reset button in the lower right.

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After injecting gas and after the well stabilizes, notice the average oil rate in the chart on the upper left says 90 bopd.

You have successfully unloaded the well!

Task 2: Parametric Study

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Limits: where this gas lift design stops working, i.e. where you can no longer unload to the third mandrel.

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Change one of the values below and then click “Load Brine”, which will start the process over, check the liquid rates while you are

changing:

▪ PI from 0.1 to 20.

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GOR from Zero to 5000

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Water Cut from Zero to 100%

Note: You might want to maximize the Simulation Speed and keep the Lift Gas rate at 300mscfd.

Task 2: Continued

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Will gas lift still work if the well flows on its own?

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Try resetting the case and changing the SBHP to 5,400 psi. The well should flow. Now, add 300 mcfd of lift gas.

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Does gas lift make an improvement?

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In terms of Artificial Lift types, no pump design can work across these ranges. Gas lift is very forgiving.

Task 3: Stand Full before Gas Lifting

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We have assumed that the well stands full before gas lifting. This is the worst case for a gas lift design.

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Reset the case and click the Stand Full button. Turn on the lift gas to 300mscfd.

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When the casing holds a lot of gas already, additional lift gas must further compress the gas in the annulus before the pressure can rise. This slows the rate of casing pressure increase.

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Due to the lower static gradient, the upper valves are not even necessary. Report your observation(s).

Task 4: Simplified Design

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If you are quite certain that the well will not stand full of liquid, you can greatly simplify gas lift designs by omitting upper valves.

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Reset the case, click on Stand Full and make the fluid level fall in the tubing. Try making the two upper valves into Dummy valves.

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Turn on the Lift Gas and watch the CHP. It may rise to 1440 psi since his installation has about 1440 psi of injection pressure.

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You can try to lower the lift gas rate to keep the CHP low, and it can inject at the third mandrel with only about 1200 psi.

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A simple design has very little that can go wrong with it. Report your observation(s).