Abstract: Three-Phase Fluid Migration with Solubilities in a Two-Dimensional Basin Simulation Model

Zhihuai Yu, Ian Lerche

Three-phase fluid migration with solubilities is examined in a two-dimensional basin simulation model. Darcy's Law is applied with the driving forces of excess pressure from disequilibrium compaction, buoyancy and capillary pressure controlling flow of different fluid phases. Relative permeabilities are related to the saturation fractions taken by each fluid phase in the pore space.

The test results show that solubilities (which are temperature and pressure dependent) have a significant impact on both primary and secondary hydrocarbon migration and accumulation. The spatial and temporal patterns of hydrocarbon migration and accumulation with solubility are various, depending on the specific geological, geothermal and geochemical conditions.

Because of the dynamic features of hydrocarbon migration tied to phase saturation through relative permeability variations, and to phase solubility through temperature and pressure dependence, this study indicates that the solubility and saturation effects must be considered in exploration assessments of hydrocarbon accumulation histories. Application of the phase-dependent migration model to a geological section descriptive of the Hammerfest basin, Barents Sea shows that Tertiary uplift and erosion, which leads to leakage of hydrocarbons, are likely the dominant cause of the majority of exploration subcommercial holes in the Hammerfest basin, Barents Sea.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994