While drilling, the drilling lubricant (mud) and cuttings that come to the surface (or if a core is taken) would be monitored for tiny traces of hydrocarbons (known as mud logging). If traces are found this would indicate you have hit a resevoir.
Many test's can indicate you have hit a pay zone i.e. Smelling, Staining, Bleeding, Oil on Mud stream, Solvent Cut Test, Acetone Test, Gas Chromatograph Test and Fluorescense Test.
For example with fluorescence - from dull-brown for heavy oils and tars through to bright-yellowish and bluish-white for very light oils and condensates.
Post drilling a wireline log can be run. It's an instrument that gets dropped to the bottom of the well and then it records parameters on a chart on the way up, such as resistivity, conductivity and formation pressure, as well as sonic properties and wellbore dimensions.
This data is used to size up the reserve. The tool can be included in the drill string to send this data back live while drilling also.
The definitive test is a Drill Stem Test, where the well is packed above and below where you want to test, then the well is opened and a flow rate test is performed.
The time to do the tests varies. Some are done live while drilling, some you need to take the drill string out to do. If they get background gas reading's while drilling i'm sure they will announce it.
Anyway thats a rough guide...
HOG Price at posting:
24.0¢ Sentiment: Buy Disclosure: Held
