Equipment Development for Gas-Lift in Sub-Sea Operations

Roger Stinson

Product Manager - Gas Lift

Schlumberger Completions Systems

Deepwater Gas-Lift Challenges

• Limited & costly intervention opportunities– requires highly reliable equipment– operational flexibility

• Higher gas injection pressures– 3000 psi to 5000 psi– evaluate current products

Current Projects

• RIPC Gas Lift Valve – normally open gas lift valve

• 3000 PSI Gas Lift Valve – evaluate current products

– development

• Surface Controlled Downhole Flow Control– WRFC-H -Hydraulically Controlled

– WRFC-E - Electrically Controlled

RIPC Gas Lift Valve Application

• Developed for applications which will use two levels of injection pressure.

• One point of injection for low operation injection pressure and one point of injection for high operation injection pressure

• Use of this valve requires a low injection pressure for lifting from a shallow depth

• A switch to a high pressure system to accommodate a deeper injection point will close the valve

Open Closed

Open Closed

RIPC FlowRate vs Downstream pressure

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

1000 1100 1200 1300 1400 1500 1600 1700 1800

Downstream Pressure psig

Flo

w R

ate

mm

cfd

Projected Natural Gas Flow Rate Minimum Tubing Pressure

Maximum Tubing Pressure Gas Requirement

Nitrogen Flow (Measured)

Specification 1

RIPC FlowRate vs Downstream pressure

0.0

1.0

2.0

3.0

4.0

800 900 1000 1100 1200 1300 1400 1500

Downstream Pressure psig

Flo

w R

ate

mm

cfd

Nitrogen Flow (measured) Projected Natural Gas Flow Rate Minimum Tubing Pressure

Maximum Tubing Pressure Gas Requirement

Specification 2

3,000 PSI Gas Lift ValveDevelopment Project

1-1/2” IPO Gas Lift Valve - 3,000 PSI TRO

• Currently have 3 existing 1-1/2” IPO Gas Lift Valve Designs

• Limited to 1,700 PSI Dome Pressure

• Test R-20, SR-20 & N-17R @ High Pressure To Determine Limitations

• Analyze Test Results

• Make Design Modifications For 3,000 PSI WP

• Manufacture Final Design Prototypes

• Test Final Design

• Flow Test Final Design

Scope of ProjectTo develop a gas lift valve capable of greater setting pressures (up to 3000 psi desired) for higher pressure injection systems in sub-sea completions. Testing to include:

Phase I - Probe Testing - Cycle Testing

Phase II - Probe Testing - Cycle Testing - Gas Flow Testing

Probe Testing

Probe Testing

measures the amount

of stem travel the

valve achieves per psi

of pressure.

Dome Pressures:

1000, 1500, 2000,

2500, 3000

Cycle TestingCycle Testing measures the fatigue life of the bellows. Pressure is applied through the ports and across the bottom of the ball. One full cycle occurs upon opening and full closure.

Cycle Testing - Results

• Valve set to 3000 psi Dome charge

– results for all valves were unacceptable

• N-17R Slightly better than R-20

• Valve set to 1500 psi Dome charge

– mixed results

• R-20 Considerably better than 3000 psi test

• N-17R No significant improvement over 3000 psi test

• Test ringed bellows and alternate material

– Ringed bellows results comparable to no-ringed bellows

– Alternate material improved cycling-higher load rate

Current Status

• Development valve - alternate bellows material

• Test additional alternate bellows designs &configurations

– load rates

– cycle testing

• Future development decisions based on ongoing evaluation

Wireline Retrievable Flow Control- Hydraulic & Electric

WRFC - Wireline Retrievable Flow Control

• Variable Orifice Gas Lift Valve• Side Pocket Mandrel Mounted• Wireline Retrievable• Electric or Hydraulic Operation• Same Operating System for Electric

Permanent Down Hole Gauge

Side pocket mounted hydraulically actuated Flow Controller that is remotely controlled from surface. Designed for flow rates up to 10,000 BBL/D, 30MMSCF/D.

Description

Features

Status 8 successful installations per August 2000

• Gas Lift and SCSSV based technology• Retrievable Valve for repair or replacement• Actuated through a single 1/4”

control line• Customizable 6 position actuator

Wireline Retrievable Flow Control Hydraulic (WRFC-H)

Wireline Retrievable Flow Control Electric(WRFC-E)

• Electrically actuated• Retrievable Flow Control Valve

Description

Features

Status Field Test Q-1 2001

• Based on Gas Lift technology• Retrievable valve for repair or replacement• Actuated through a single 1/4” tubing encased electrical conductor line• Infinite position actuator• Annular and tubing pressures

Retrievable Flow Control Valve

Actuator

Bottom cross-section view

Electronics Cartridge

Sapphire Gauges

WRFC/EGLV Overview

WRFC Projector.exe

WRFC Specifications

Electric Hydraulic

Max temp: 150 C 200 C

Pressure rating: 5/10K PSI 5/10K PSI

Flow area (see note): 0.75 in2 0.75 in2

Instrumentation Annular & tubing SeparatePressure & Temp

Control resolution: Infinite Increments

Note - Equivalent flow area

Norsk Hydro, TOGP

Safety Valve

WRFC-H - used to control gas

Penetrations in Gas Cap

Sand control completion in oil zone

• 30/40 Subsea installations planned

• Control gas from gas cap to lift

• Longer producing life

• Eliminates compression facilities