Title: Apresenta
1PETROBRAS - Petróleo Brasileiro S.A.
2002 GAS-LIFT WORKSHOP
Gas-lift Automation Pilot Project
HOUSTON - FEBRUARY, 2002
Edson Henrique Bolonhini PETROBRAS -
UN-RNCE Galileu Paulo Henke Alves de
Oliveira PETROBRAS - UN-BC
2Gas-lift automation - TARGETS
- GUIDELINES
- control Pwf (bottom hole flowing pressure)
- action over Pcas (wellhead casing pressure)
3Gas-lift automation - TARGETS (cont.)
- OBJECTIVES
- to get the minimum Pwf by controlling Pcas
- to observe the well delay time after a change in
Pcas - to verify the adequacy of a PID controller for
Pcas - to verify the adequacy and controllability of
globe valves for lift-gas injection - to observe the effects of ambient temperature on
Pwf
4Hardware
- Instruments
- bottom hole pressure transmitter
- wellhead flowing pressure transmitter
- gas-lift supply pressure transmitter
- gas-lift rate transmitter
- gas-lift control valve
- ambient temperature transmitter
- data acquisition and control module
5The well
Tubing Ø 2 3/8 Casing Ø 5 1/2 Depth 1500
m Gas-lift valves Ø 1/8 2 IPO 1 venturi Liquid
flowrate 25 m3/d GOR 130 BSW 35
Bottom hole pressure and temperature transmitter
1500 psi / 100 C
6Instruments
Control valve globe Ø ¾
Radio and data acquisition and PID control
7Monitoring
Supervision and control room
8Results
Data obtained from Dec/2001 until Jan/2002
9Flow regime effects on Pwf
Oscillation
Heading
10Ambient temperature effects on Pwf
Night
Day
11PID control on casing pressure
12Automatic reactivation - Pwf gt 53 kgf/cm2
PID action
Reactivation algorithm
Gas compressor shutdown
Gas compressor start-up
13Condensate effects on Pwf
Injecting gas through the 2nd GLV Circulating
liquid through Venturi GLV
Reactivation algorithm Pwf gt 53 kgf/cm2
Rain
14Final remarks
- It is possible to control the Pwf behaviour
through the proposed approach - PID controller-globe valve assembly showed to be
efficient and beneficial - Ambient temperature has effect on the well
behavior and it shows the importance of a dynamic
injection control - The experiment allowed us to evaluate the system
response with time - A global control algorithm should consider the
conditioning of Pwf signal and its tendency
15PETROBRAS - Petróleo Brasileiro S.A.
2002 GAS-LIFT WORKSHOP
Gas-lift Automation Pilot Project
HOUSTON - FEBRUARY, 2002
Edson Henrique Bolonhini PETROBRAS -
UN-RNCE Galileu Paulo Henke Alves de
Oliveira PETROBRAS - UN-BC