2015年-世界发展银行全球_CNG_for_Commercialization_of_Small_Volumes_of_Associated_Gas_102页_3mb

Summary of CNG for Commercialization of Small Volumes of Associated Gas

Core Content

Compressed Natural Gas (CNG) is a viable solution for the commercialization of small volumes of associated gas (1-15 MMscf/d) and reducing gas flaring. This report evaluates the CNG chain, technologies, market trends, and challenges for both onshore and marine applications.

The CNG Chain

The CNG chain includes four key elements:

1. Production: Involves gas pre-treatment and compression. Pre-treatment includes removing heavy hydrocarbons, contaminants (e.g., H2S, CO2), and dehydration.
2. Transportation: Can be onshore or marine. The cost is heavily influenced by gas volume and distance.
3. Receiving: Involves offloading, heating, and metering at the customer site.
4. Storage: Depends on the type of container and conditions.

CNG Market Overview

• Onshore: CNG is widely used as vehicle fuel, with over 20 million vehicles globally. It is also used for power generation and industrial applications.
• Offshore: Marine CNG is still under development and not yet commercially operational. Indonesia is a potential early adopter, with a CNG carrier project expected to start operations in 2016.

CNG Technologies

Marine CNG Technologies

1. CETech

   • Containment: Composite or X80 steel pipe; composite (ISO container)
   • Status: Concept stage
   • Capacity: 85-319 MMscf (plus 60-120,000 m³ oil)
   • Certification: Under development

2. EnerSea - VOTRANS™

   • Containment: X80 steel cylinders
   • Status: Advanced concept stage
   • Capacity: 75-1,000 MMscf (ship)
   • Certification: Under development

3. Sea NG COSELLE™

   • Containment: Coiled X70 line pipe forming a carrousel
   • Status: Advanced concept stage
   • Capacity: 51-531 MMscf (ship)
   • Certification: Under development

4. TransCanada CNG Technologies

   • Containment: Composite reinforced steel Gas Transport Modules (GTM)
   • Status: Concept stage
   • Capacity: 12-100 MMscf
   • Certification: Under development

5. Knutsen OAS Shipping AS

   • Containment: X80 steel cargo tank cylinders (CTC)
   • Status: Concept stage
   • Capacity: 70-1,200 MMscf
   • Certification: Under development

6. Trans Ocean Gas

   • Containment: Composite HDPE and fibreglass cylinders (MEGC)
   • Status: Concept stage for MEGC container only
   • Capacity: Variable
   • Certification: Under development

Onshore CNG Technologies

• Steel Tube Trailers: Max capacity up to 0.29 MMscf, pressure 187-227 barg
• GTM Type III Cylinders: Max capacity up to 0.44 MMscf, pressure 248 barg
• Lincoln Type IV Cylinders: Max capacity up to 0.36 MMscf, pressure 250 barg
• Galileo Virtual Pipeline®: Max capacity up to 0.25 MMscf, pressure 200-250 barg

Cost Analysis

Offshore CNG Transport Costs (USD2015/MMBTU)

Onshore CNG Transport Costs (USD2015/MMBTU)

Main Constraints for CNG Recovery

• Gas Composition: Varies between fields and wells, affecting treatment needs.
• Transport Pressure and Temperature: Optimal is 100-250 barg and low temperature to maximize efficiency.
• Gas Quality: Must meet specifications for pipeline injection, including dew points, sulphur content, and Wobbe index.
• Production Rate: Continuous and variable, requiring flexible CNG offtake solutions.
• Offloading Rate: Must be continuous and compatible with the receiving infrastructure.
• Safety: High pressure transport requires robust containment, regular inspection, and risk mitigation measures.

Key Market Trends

• USA: CNG is used for vehicle fuel and power generation, with growing interest in marine transport.
• China: CNG is popular for vehicle fuel, and the market is expanding with government support.
• Pakistan: Has a significant CNG vehicle fleet, supported by government initiatives.
• Indonesia: Shows potential for marine CNG with a new carrier project in Lombok.
• Nigeria, Iraq, and Other Countries: CNG could be used for power generation, transport, and industries, especially in regions with marginal gas fields.

Conclusions

• Onshore CNG transportation is well established and economically viable for volumes up to 5 MMscf/d and distances up to 800 km.
• Marine CNG is still under development but could be viable for larger volumes and longer distances (up to 2000 nautical miles).
• CNG offers an alternative to LNG for small volumes of associated gas and is a key solution for reducing gas flaring.
• The success of CNG commercialization depends on technology development, cost efficiency, and regulatory approval.