2001 GAS LIFT WORKSHOP

Transcription

1 2001 GAS LIFT WORKSHOP PETROBRAS DEEPWATER GAS LIFT PROJECT Guilherme de Almeida Peixoto PETROBRAS / E&P- Campos Basin B. Unit José Eduardo Mendonça da Silva PETROBRAS / E&P- Rio B. Unit José Octavio do Amaral Baruzzi (In Memorian) HOUSTON - USA - FEBRUARY, 2001

2 DEEPWATER GAS LIFT PROJECT OBJECTIVE Assure and increase production from deep water oilfields using Continuous Gas Lift (CGL) EXPECTED BENEFITS Production increase per well: 3% to 9% Workover frequency reduction Increased operational flexibility (at well start-up for example) Most of the results from this project have immediate application.

3 DEEPWATER GAS LIFT PROJECT SUBPROJECTS 1 - Scenario Studies 2 - Equipment 3 - Softwares 4 - Automation

4 SCENARIO STUDIES Focus on : 1 - Campos Basin Deepwater Oilfields 2 - Generic m Water Depth oilfield

5 Main Oilfield Data: SCENARIO STUDIES Water Depth: 1000 to 3000 m Reservoir Datum: to m Well to Platform Distance: 1.5 to 12 km Oil Specific Gravity: 12 to 30 API Static Reservoir Pressure : 200 to 300 kgf/cm 2 Productivity Index : 10 to 150 m 3 /d/kgf/cm 2 Formation GOR : 50 to 100 m 3 /m 3

6 CAMPOS BASIN OIL PRODUCTION PRODUCTION METHODS 60% 7% 33% NATURAL FLOW GAS-LIFT ESP BCS

7 Ultra Deepwater Gas Lift Injection Advantages of Subsea Gas Injection Point : Operational Flexibility: reduce the number of downhole GL valves prevent or reduce instabilities and severe slug easy way to start-up the well use of conventional subsea valves and chokes Single injection point in the flowline in deepwater wells

8 Gas Injection Point Comparison Example of Scenario Studies Result BHP= 300 Kgf/cm2, PI= 30 m3/d/kgf/cm2, L fl = 1000 m, BSW= 0 % 3000 Líquid flowrate (m3/d) RISER WH WELL 0 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 WD / Reservoir Datum Ratio

9 EQUIPMENT Guidelines Development of Gas Lift Valves (downhole and subsea) Acquire better knowledge about conventional and new gas lift components ( dynamic tests) - Petrobras Gas Lift Valve Test Site

10 Gas Lift Valve Development Normally Open GL Valve Venturi Type GL Valve 3000 psi bellows pressure GLV Electric GL Valve

11 Novos Normally modelos Open de Válvulas Gas Lift de Valve Gas Lift Main Characteristics: valve opens with low casing operation pressure valve closes with the increase of casing pressure Schlumberger development for Petrobras Bench tested in SwRI and Petrobras Teste Site Field tested in platform PCH-2 in Campos Basin

12 Venturi Type Gas Lift Valve SLB Nova and Petrobras Venturi Valve were tested by Petrobras : SLB Nova (Petrobras Test Site and field test) Petrobras Venturi Valve (Petrobras Test Site ) Both valves have presented excellent performance

13 JIP and Partnerships 3000 psi bellows valve development under a Cooperation Agreement with Schlumberger allows deeper injection points cycling and load rate tests completed Field test planned for june/2001 EGLV - Electric Gas Lift Valve Petrobras is a member of a JIP headed by Schlumberger orifice changes by remote operation prototype test planned for march/2001

14 Petrobras Gas Lift Valve Test Site UTVGL - Performance Tests

15 Desempenho de Válvulas Venturi e Orifício ( curvas levantadas na UTVGL - Aracaju - SE ) Venturi x Orifice Valve Performance Curves Gas Vazão Flowrate de gás Downstream Pressão pressure Orifice and Venturi have been extensively tested. Starting IPO tests.

16 Software: MARLIM simulator (Multiphase and Artificial Lift Modeling) Main Characteristics: Petrobras in house continuous development, that incorporates all acquired technology P & T accurate profiles in steady-state multiphase flow CGL design and troubleshooting dynamic behavior for GL valves gas hydrate prediction models incorporated ESP and Jet Pump simulators included FLOWLIFT Transient Simulator Interface

17 Temperature Profiles Comparison Test 03/01/1999 Marlim Simulator A Simulator B 1000 Depth (m) Temperature (C) Petrobras paper will be presented today in ETCE 2001

18 Software: FLOWLIFT simulator Main Characteristics Petrobras team + consultant development Accurate P & T profiles in transient multiphase flow Kick-off analysis and operation in subsea GL wells N2 and natural gas coil tubing operation simulation Chokes and GL valve models incorporated Transient analysis due to sudden valve closure Simplified reservoir transient model Status: software developed, under validation Specific presentation will be made here tomorrow

19 Transient Typical Modeling Configuration Geometry and operation modes: Prod. + injection flowlines well prod. tubing + annulus production + injection risers Coil tubing operation mode Subsea X-Tree valve operation mode Chokes and GL Valves anywhere Fluids managed by FLOWLIFT: formation oil and water formation gas natural injection gas N2 injection gas Completion Fluid

20 Gas Lift Automation Goals optimization and automation of gas allocation per well automatic instabilities control specialist system for CGL problems diagnose