ACARP ACARP ACARP ACARP
Underground

Gas Detection Technique and Equipment to Continuously Monitor Gas in Drill Fluid

Underground » Ventilation, Gas Drainage and Monitoring

Published: August 94Project Number: C3077

Get ReportAuthor: Les Lunarzewski | Lunagas

A fluid logging system for underground drilling can be used as a complementary method for the recognition of gas and gas-rock outburst prone conditions ahead of the face and along an inseam drill hole.   Mud logging technology has been used in surface boreholes in the oil industry, for a considerable time with great success. An underground version of the system promises to deliver valuable data, however equipment alteration is necessary due to difficult underground conditions and safety requirements.  Project C3077 was aimed at the development and evaluation of a system suitable for Australian underground coal mining conditions. Suitable equipment has been identified and selected, however a gas trap unit still needs to be designed and tested specifically for use underground.

Definition of the Problem and Description of the Proposed Technology

Recognition of gas and gas-rock outburst prone conditions which may exist ahead of the development face is essential for safe and efficient development drivage. Methods used to date are not fully satisfactory.

To complement existing methods a means of logging underground drilling fluids could be useful. Appropriately designed equipment, approved for gassy underground mining conditions, could be useful for recognition of gas and gas-rock outburst prone conditions ahead of the face.

Monitoring the quantity and composition of gases in the drilling fluid should provide continuous real time information about both the gas content and the permeability of the coal seam along an inseam drill hole.

The proposed system is based on surface mud logging design and technology which has been used in the oil industry with a great deal of success. However, transfer of this technology underground requires specific research and the selection of appropriate equipment that will conform to Australian conditions and standards.

The aim of the project was to identify select and where necessary develop equipment and technology for an Underground Drilling Fluid Logging System suitable for Australian underground coal mining conditions.  The specific objectives were to:

  • Identify and review existing state-of-the-art equipment for measuring the amount, composition and character of gas influx at particular distances in horizontal, inseam drill holes. 
  • Identify and select equipment for an underground drilling fluid logging system suitable for Australian underground coal mining conditions. 
  • Prepare cost estimates and guidelines for the final design, purchase and implementation of the system.

Summary of Work Accomplished

Material on the following subjects has been researched:

  • surface mud logging technology
  • gas detection and measurement
  • underground outburst conditions

Conclusions

  • All necessary equipment for a system design which conforms to Australian underground coal mining conditions has been identified. 
  • Details of equipment and suppliers are specified in the section titled 'Equipment Selection and Cost' and in Appendix 'A'. 
  • To introduce the system into underground coal mines, certain changes to underground drilling practices are necessary:
  1. the use of a standpipe and stuffing box to direct both drilling fluid and cuttings to the proposed gas trap 
  2. installation of a gas trap to separate the gas from the drilling fluid and allow the drilling fluid and cuttings to be discharged continuously to the heading floor or to a special container. 
  • The gas separator (gas trap) should be designed specifically for the underground system initially in the form of a cylinder with interior baffles to hinder the flow, and followed by laboratory and underground tests. The gas trap which is proposed is a simple device which does not require a power supply and is without any internal moving parts. 
  • The initial design of the system should simply aim at obtaining a gas signature of the strata as a relative gas volume against drilled depth. Once this has been achieved a quantitative approach could be taken. 
  • The system prototype is based on in-seam hole conditions and existing underground gas flow parameters at Cordeaux Colliery using a modified drill rig and a newly introduced data logger. 
  • The system can also be transferred and used in conditions particular to other coal mines. 
  • Equipment has been selected on the basis of technical discussions with manufacturers, suppliers and various specialised companies including: MSA, Control Systems Technology, Mine Instrument Services, Zellweger, Systrix, BHP Research Newcastle Laboratories and BHP Steel Collieries Division. 
  • The data logger currently selected (Underground Drilling Monitor) has only one free 'input' which is not sufficient for the system. This needs to be redesigned to accept the following inputs, providing the suggested equipment is used:
  1. 40-200 mV (x2) - flow
  2. 0-2 V - CH4%
  3. drilled depth (already utilised by BHP) 
  • For the initial design, air ejector suction can be regulated by a manual valve, however, for the final product, suction should be adjusted by an automatic valve controlled by an Underground Drilling Monitor. Therefore, one output channel would be required in the monitor providing a 4-20mA control signal to the valve.
  • For the measurement of gas flow Rosemount Instrument's Differential Pressure Transmitter has been chosen, however, an alternative option does exist: carrying out the flow measurement using passive pressure and differential pressure transducers offered by Transmetrics Inc. They are small devices, very well suited for compact, portable design, however, utilisation of these devices would require some electronic design, signal conditioning and consequent approval for underground use.
  • Current off-the-shelf units are preferable for the prototype system where as the final system design should consider the use of passive transducers instead.
  • On the basis of the selected equipment and taking into account the above conclusions and recommendations, the prototype system should be designed, constructed and trialed underground to confirm the value of the data delivered by the system. If the trials are successful the final product could be designed with emphasis on automatic operation and portability, which could be achieved using:
  1. passive pressure and differential pressure transducers for flow measurement
  2. a remote control valve for air ejector suction control 
  • The proposed technology offers the only known system to identify and recognise, on a continuous basis, gas content and permeability of a coal seam ahead of a driven heading face.

Underground

Health and safety, productivity and environment initiatives.

Recently Completed Projects

C34019Longwall Bretby Cable Handling Monitoring With Fibre Optics

This project examined the potential of using fibre optic sensing tec...

C27049Mine Machine Radar Sensor Integration

The aim of this project was to develop an integrated radar sensor an...

C29007Innovative Coal Burst System To Investigate The Influence Of Confinement Loss And Pre-Conditioning On Coal Burst Mechanism

The challenges associated with designing and operating a safe and pr...

Underground

Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C33035High Water Recovery, Low Cost Desalination Using PV-Powered Membrane Capacitive Deionisation (Mcdi)

Capacitive deionization is a robust, energy efficient and cost effec...

C28035Topsoil Deficits In Site Rehabilitation Accelerated Transformation Of Spoils To Functional Soils

The incorporation of commercial biological amendments (compost, worm...

C34036Tyre Handler Testing Rig Stage 2: Lifting Trials

Tyre handling is a major source of risk in surface mining operations...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C34060In-Situ Investigation Of Coke Structure Formation Under Stamp Charged Coking Conditions

Stamp charged cokemaking has emerged as an effective technique to im...

C34062Improving The Classification Of Microstructure Distribution In Coke CT Images Using Deep Learning And Lineal Path Calculations

This project builds on a number of earlier projects that have helped...

C29071Source Of Variability Of Reactivity Of Coke In The CSR Test

The Coke Strength after Reaction (CSR) test is used worldwide to det...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL)

This third and final stage of this project was the culmination of a ...

C29069Low-Cost Catalyst Materials For Effective VAM Catalytic Oxidation

Application of ventilation air methane (VAM) thermal oxidiser requir...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community

NERDDC

National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook

NERDDC