Well Log Interpretation In Permafrost

Permafrost or permanently frozen ground covers a large portion of the arctic sedimentary basins on Canada and Alaska. The thickness of the permafrost layer varies up to a maximum of 1300". Some accumulations of hydrocarbons in the permafrost have been reported. This paper first describes a method for establishing the temperature distribution around a well bore in these unique surroundings. Then, the basic borehole environments which might occur under a variety of drilling and completion programs are discussed. The laboratory determined data is presented to show the effects of below freezing temperatures upon fluid and rock properties. Finally an interpretation from actual field logs, based on the previously described investigation, is given. It is concluded that a knowledge of the physical properties of permafrost, its temperature distribution and the proper field procedures are all important to a quantitative interpretation of the well logs in permafrost.