GasMapper is a coal focused technical service that uses the industry’s only downhole wireline Raman spectrometer and best-in-class open hole permeability test platforms to deliver key information regarding gas distribution. Data deliverables from the service include gas composition, gas content, critical desorption pressure, gas saturation, required drawdown to drainage and permeability. It enables coal mine operators to explore faster and more cost effectively without sacrificing safety, even in deeper, gasier coals.






The Complete GasMapper Solution - Coal Mine Safety and Emissions Reduction


The problems of discrete measurements, accuracy limitations and cost constraints associated with the traditional coring and flow capacity testing in dedicated HQ holes is overcome using WellDog’s GasMapper testing service. This combines WellDog’s proprietary Reservoir Raman Spectroscopy with standard open hole drill stem testing technology.

The GasMapper system performs direct laser based measurements of solubilised methane gas concentration in the water extracted from the coal seam cleats during flow capacity tests conducted downhole, using WellDog’s PermMapper drill stem testing technology.

The measured methane gas concentration is equated to a partial pressure of methane, which can then be equated to coal gas content using appropriate Langmuir isotherms values.

The PermMapper system features a reset function, allowing flow capacity of multiple seams in the same well to be determined in a single trip. In this way, a stratigraphic map can be generated, with accurate gas content and flow capacity data attributed to each seam quickly, in a single trip, in the chip (PQ) holes, thereby eliminating need for many of the dedicated HQ holes, and associated additional costs.

This revolutionary test can be performed in PQ-sized chip holes, so no additional drilling is required to measure coal gas content and permeability.

  • Proven technical service used in Australia and Mozambique to successfully map gas distribution
  • Ability to map gas composition, gas content, critical desorption pressure, gas saturation, required drawdown to drainage
  • Delivery of key reservoir producibility data, permeability, average reservoir pressure, radius of investigation and total skin
  • System can be deployed in slimhole HQ and PQ exploration bores which in some cases reduces exploration costs and time
  • Does not require supporting on-site laboratory, so suitable for remote locations
  • Allows simultaneously geochemical analysis of methane, carbon dioxide, nitrogen and higher hydrocarbons
  • Measurement of fluid phases, both gas and water, allows bypass of the petrophysical heterogeneity that are present in core samples
  • In situ analysis allows analysis of hundreds to thousands of fluid samples for each coal seam insures accurate representation that’s impossible to achieve with a few samples
  • Combination of in-situ gas measurements with adsorption isotherm data delivers the most accurate and representative gas-in-place data available
  • Results from this service can be made immediately available post job
  • Reserve auditors will book reserves using data acquired from this service
    GasMapper is a wireline-deployed tool that is designed to work in-situ. This means real-time, actionable data.  No more waiting for core analyses from the lab.