000			02458nab a2200217 4500
005			20260520000321.0
008			260224s2016 xxu ing
041			_aInglés
245	0	0	_aHydrogen sulfide formation, fate, and behavior in anhydrite-sealed carbonate gas reservoirs _bA three-dimensional reactive mass transport modeling approach
260			_a _b _cmayo 2016
270			_a04/07/2016 ; 04/07/2016
300			_a21 p. ; 843-865
520			_aTranscripción del resumen del autor: A novel hydrogeochemical modeling approach is developed to unravel thermochemical sulfate reduction (TSR) in hydrocarbon reservoirs. Our numerical model couples a web of interconnected hydrogeochemical reactions to three-dimensional (3-D) and reservoir-wide diffusive mass transport. Our modeling approach simulates a semigeneric gas reservoir sealed by anhydrite. The calculated diagenetic processes fit the observations in reservoirs affected by TSR: formation of water, precipitation of calcite, metal (di-)sulfides, and elemental sulfur as replacements of dissolved anhydrite at the expense of CH4(g), as well as formation of hydrogen sulfide (H2S). By varying input parameters, the crucial factors controlling TSR have been identified. Our results highlight that reservoir-wide diffusive mass transport is one prerequisite for TSR. An increase in the rate constant of abiotic sulfate reduction (ASR) and in diffusive mass fluxes, as well as lack of precursor minerals for metal (di-)sulfide precipitation, can increase the souring intensity and accelerate H2S outgassing. In contrast, precipitation of elemental sulfur, which is stable according to the chemical thermodynamics, weakens H2S formation. Our modeling shows that TSR is complex and cannot be represented by the single reaction ASR and by simple correlations between the rate constant of ASR and the H2S gas content. The application of 3-D reactive transport modeling presented here, despite its semigeneric nature, provides a good example of how such an approach can be used ahead of drilling. Our modeling helps to investigate TSR in time and space to quantify the mass conversion of all reactants involved within this web and to predict the souring level.
581			_a5
773	0		_tAAPG Bulletin _g100
942			_cARTICULO
100	1		_aFu, Yunjiao _955425
100	1		_aVan Berk, Wolfgang _955426
100	1		_aSchulz, Hans-Martin _955427
999			_c189607 _d189607