Gary Fiselier Measurement Lead, EnCana Corporation

Transcription

1 Gary Fiselier Measurement Lead, EnCana Corporation

2 Meter Types Quantity Rate of Flow Mass Positive Displacement Diaphragm Rotary Impeller Rotary Vane Differential Pressure Orifice Venturi Annubar Pitot Tube Velocity Turbine Vortex velocity Vortex Shedder Ultrasonic Acoustic Infrared Coriolis force Thermal type 3

3 Considerations for Meter Selection Rate of Flow or velocity Decline in production over time Initial pressure and decline over time Sand and liquids Location Power requirements Maintenance Volume interpretation 4

4 Meter Types Positive Displacement Accuracy Pros Cons Typical Applications Diaphragm 1.0 % Rotary 1.0 % Good accuracy Excellent range Reliable and durable Wide variety of outputs Compact 1000:1 range ability Reliable 100:1 range ability Bulky Low pressure Cannot handle liquids Must be removed for service Limited low flow Cannot handle liquids Limited high pressure range Must be removed for service Custody transfer Residential Industrial Low flow rates Sales gas Fuel gas 5

5 Meter Types Orifice Accuracy Pros Cons Typical Applications % No moving parts Relatively inexpensive Proven 50:1 range ability with all plates Not damaged by slugs Low maintenance cost Orifice plates can be changed quickly Only 3:1 rangeability with one plate Meter run required Sensitive to density changes Difficult volume interpretation Permanent pressure loss Test and group gas Wellhead gas Gas plant inlet and sales 6

6 Meter Types V Cone Accuracy Pros Cons Typical Applications % No moving parts Relatively inexpensive Proven Rugged Not damaged by slugs Meter run not required. Compact installation Low maintenance cost Only 10:1 rangeability with single cone Sensitive to density changes Difficult volume interpretation Permanent pressure loss Test and group gas Wellhead production 7

7 Meter Types Other Differential Accuracy Pros Cons Typical Applications Pitot Tube % Annubar % Low initial cost Field calibration Low maintenance cost Low initial cost Field calibration Low maintenance cost Poor accuracy Effected by vibration Needs minimum velocity in order to obtain accurate measurement Poor accuracy Effected by vibration Needs minimum velocity in order to obtain accurate measurement High volume flare High volume flare 8

8 Meter Types Turbine Accuracy Pros Cons Typical Applications 1.0 % Good range ability Direct readout Wide variety of outputs Low pressure drop Limited low flow Cannot be used in sour service Not tolerant to hydrates or dirt Cannot be field calibrated Sensitive to density changes Sales gas Fuel gas 9

9 Meter Types Vortex Shedder Accuracy Pros Cons Typical Applications % Low pressure drop No moving parts Tolerant to gas and junk Ease of calibration 20:1 range ability Not affected by specific gravity Immune to vibration Low viscosity Meter run required Specialized personnel required to install and maintain Condensate Water Gas 10

10 Meter Types Ultrasonic Accuracy Pros Cons Typical Applications < 1.0 % Low pressure drop No moving parts Self diagnostic electronics Very accurate Meter run required Specialized personnel required to install and maintain Must be removed to be calibrated Not tolerated to hydrates and junk Sensitive to density changes High cost Sales gas 11

11 Best Meters for Field Use Orifice most common (since 1911) with V Cone another good alternative: They are the most cost effective, both initial cost of the meter equipment as well as the maintenance costs Meets metering uncertainty requirements Can be serviced on site without removal Orifice plates are cheap allowing for a change in range ability without changing meter run Little or no power depending on the recording device 12

12 Typical Orifice Meter Installatio n

13 Development of Standards (IMG) Canadian industry association made up of individuals from many producer companies IMG works with the Alberta Government to work through measurement standards and recommended industry practices Generally follow recommended practices as published from the American Gas Association (AGA) as well as the American Petroleum Institute (API) Develop reasonable standards for industry to follow 14

14 Accurate Measurement Revenues from residue gas has become increasingly important in the economic viability of oil facilities. Measurement is an important tool to maximize the recovery of residue gas thus the total revenue from the total facility. Poor measurement costs money. 15

15 Accurate Measurement Benefits of accurate measurement include: Different companies own different wells in a facility allows for more accurate allocations Reduce metering uncertainty both at a well level as well as across the whole facility Monitor reservoir performance and performance of enhanced oil recovery projects CO2 injection, polymer floods, gas recycling, etc. Better decisions based on more accurate measurement data 16

16 Costs of Poor Measurement Audit costs Business relationships Regulatory relationships Data rework costs Lost revenues Lost opportunities

17 Questions?