Location

Rolla, MO

Session Start Date

6-11-1999

Session End Date

6-17-1999

Keywords and Phrases

Gob Well; Gob Well Flaring; Gob Well Safety; Methane Drainage; Gob Gas; Methane Emissions; Greenhouse Gas

Abstract

Currently, over 30 U.S. Coal Mining operations employ a system of degasification to assist in reducing the emission of methane into their mine ventilation systems. All of these mines use vertical gob wells. This is an effective gob de gasification technique for U.S. longwall coal mining operations, particularly when prime movers apply suction to the wellheads (active gas extraction). In most cases mine operators discharge gas recovered from gob wells directly to the atmosphere. This practice poses safety and environmental concerns, and wastes a potential resource. In the U.S. there are no standards for equipping actively extracted or passive gob wellheads. Some states require safety measures such as flame arresters, backflow check valves, fenced enclosures and lightning protection, while some have no guidelines. Many gob wellheads in the U.S. operate as passive ventilation boreholes, some of which operate as "open holes" and are not equipped with any safety measures as all. Under ideal conditions, operators collect gas (methane in air mixture) directly at the gob wellhead for sale or on-site use. However, because of gob well gas production characteristics (gas quality and quantity), the necessary coordination between de gasification and mine ventilation systems, and because of the economics of commercializing this gas, coal mine operators commonly vent this resource and thereby emit a potent greenhouse gas. This paper presents a system of controlled gob gas flaring that would improve current gob wellhead safety and would encourage refined gob wellhead design and operating practices. It includes a conceptual design of a gob well flare that incorporates safety features and operating practices based on American Petroleum Institute standards. The paper concludes by summarizing the safety benefits, the global environmental benefits, and the potential financial benefits to mine operators of application of this system in the U.S.

Department(s)

Mining and Nuclear Engineering

Appears In

U.S. Mine Ventilation Symposium

Meeting Name

8th U.S. Mine Ventilation Symposium

Publisher

University of Missouri--Rolla

Publication Date

6-11-1999

Document Version

Final Version

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Jun 11th, 12:00 AM Jun 17th, 12:00 AM

Gob Well Flaring: Design and Impact Analysis

Rolla, MO

Currently, over 30 U.S. Coal Mining operations employ a system of degasification to assist in reducing the emission of methane into their mine ventilation systems. All of these mines use vertical gob wells. This is an effective gob de gasification technique for U.S. longwall coal mining operations, particularly when prime movers apply suction to the wellheads (active gas extraction). In most cases mine operators discharge gas recovered from gob wells directly to the atmosphere. This practice poses safety and environmental concerns, and wastes a potential resource. In the U.S. there are no standards for equipping actively extracted or passive gob wellheads. Some states require safety measures such as flame arresters, backflow check valves, fenced enclosures and lightning protection, while some have no guidelines. Many gob wellheads in the U.S. operate as passive ventilation boreholes, some of which operate as "open holes" and are not equipped with any safety measures as all. Under ideal conditions, operators collect gas (methane in air mixture) directly at the gob wellhead for sale or on-site use. However, because of gob well gas production characteristics (gas quality and quantity), the necessary coordination between de gasification and mine ventilation systems, and because of the economics of commercializing this gas, coal mine operators commonly vent this resource and thereby emit a potent greenhouse gas. This paper presents a system of controlled gob gas flaring that would improve current gob wellhead safety and would encourage refined gob wellhead design and operating practices. It includes a conceptual design of a gob well flare that incorporates safety features and operating practices based on American Petroleum Institute standards. The paper concludes by summarizing the safety benefits, the global environmental benefits, and the potential financial benefits to mine operators of application of this system in the U.S.