LiftPro

IntroductionThree gas lift wells in Indonesia were selectedfor application of the LiftPro* artificial liftoptimization service following a rigorousexamination program that identified produc-tion inefficiencies.

Key to the examination process were thePhaseTester* portable well testing unit andVx* multiphase testing technology. The mul-tiphase flowmeter provided artificial lift engi-neers with real-time flow and well-test datawith minimal interference to well operations.PhaseTester equipment also allowed multi-rate tests to be recorded with real-timeresponse to a variable injection rate.

The three wells were producing a com-bined 4,800 BOPD with continuous gas lift.Objectives for the LiftPro service were to

improve stability

increase production

make more efficient use of gas liftresources

show fast results.

ChallengePrevious conventional well tests were unsuc-cessful because of lags in response time andinconsistent results following changes in theoperation of the wells.

SolutionThe LiftPro service was chosen to diagnose thedownhole gas lift equipment operation and pro-duction performance at varied surface settings.

ResultsThe overall production gain resulting fromthe LiftPro optimization service was 385BOPD. Additionally, at the operating pointsdetermined by the service to be optimum,water production from the three wells fell by 157 B/D.

A 20% reduction in the gas-injection ratewas possible once problems that had beenidentified in the wells by the LiftPro servicewere corrected, and a revenue increase ofUSD 179,000/month was realized through opti-mized operation of the three gas lifted wells.

Case study:IndonesiaHighlights

Immediate 385-B/D increase in oil production

Water-production decrease of 157 B/D

Injection gas reduction of 20% Overall revenue gain of

$179,000/month

Flow measurements from the PhaseTester unit, made using Vx multiphase well testing technology, monitor gas lift performance.

Well-by-well optimization of gas lift wells

AL_03_138_0 Schlumberger

April 2004 *Mark of Schlumberger

Produced by Oilfield Marketing Communications, Houston

www.slb.com/oilfield

Liquidrate

(STB/D)GOR

(cf/STB)

1,200

1,100

1,000

900

800

700

600

500

Gas andinjection

rate(MMcf/D)

4.2

3.6

3.0

2.4

1.8

1.2

0.6

0450 500 550 600 650 700

Oil rate Water rate GOR Gas rate Injection rate

Casing pressure (psi)

Through the LiftPro service, it was determined that the optimum operating point for this well is at a casingpressure of approximately 550 psi.