"Halliburton's integrated approach to reservoir testing and analysis provides operators with the information they need to properly characterize reservoirs and determine the net present value of assets. "

 That is to say, they run a variety of sensors down the well on a wire line to measure flow rates of oil, gas, condensate, water etc. They are able to sense the pressures and volumes that these flows are occuring at any chosen level in the well. If required they can report the condition of the well bore (is it holding up under the flow or collapsing).

 This type of information allows the well operator to estimate the volume of marketable products that can be extracted and therefore make decisions about the feasibility of investing further funds to convert the exploration well to production. If an affirmative decision is made, further "logging" may be used to optimize the design of the extraction mechanism (pipe, valves, pumps etc.)

 Hope this helps and good luck to all.

M.