A Review of Well-Log Analysis Techniques Used to Assess Gas-Hydrate-Bearing Reservoirs

Abstract

Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters, two of which, sediment porosity and gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this paper is to identify and review existing quantitative well-log evaluation techniques, which permit the calculation of sediment porosities and gas-hydrate saturations in gas-hydrate-bearing reservoirs. The well log response modeling section of this paper includes the assessment of existing gas hydrate well-log evaluation techniques used to characterize sediment porosities and gas-hydrate saturations in gas-hydrate-bearing reservoirs. In the field data application section of this paper, the gas hydrate well-log evaluation techniques described in the response modeling section of this review are tested and used to calculate reservoir porosities and gas-hydrate saturations with the downhole log data from two known gas hydrate accumulations.