The fate of CO2 derived from thermochemical sulfate reduction (TSR) and effect of TSR on carbonate porosity and permeability, Sichuan Basin, China

Constraining the Fluid History of a CO2‐H2S Reservoir: Insights From Stable Isotopes, REE, and Fluid Inclusion Microthermometry

“…In addition, the formation of H 2 S in natural gas reservoirs is of interest for drilling security and the estimation of gas degradation and presence of mineral deposits (e.g., Mississippi Valley-type deposits; Piqué et al, 2009;Powell & MacQueen, 1984). However, sulfur cycling and redox reactions such as thermochemical sulfate reduction (TSR) are not well understood on a reservoir scale and only a few natural systems have been studied including the Khuff Formation, Saudi Arabia (Bildstein et al, 2001;Jenden et al, 2015;Worden et al, 1995Worden et al, , 2000Worden & Smalgeoley, 1996), the Smackover Formation, USA (Claypool & Mancini, 1989;Heydari & Moore, 1989), Lower Saxony Basin, Germany (Biehl et al, 2016), Tarim and Sichuan Basin, China (Cai et al, 2001(Cai et al, , 2003(Cai et al, , 2004(Cai et al, , 2009(Cai et al, , 2010(Cai et al, , 2013(Cai et al, , 2016Hao et al, 2015;Jiang et al, 2014, Liu et al, 2013, and the Nisku Formation, Canada (Machel, 1987a(Machel, , 1987b(Machel, , 2001Riciputi et al, 1994). Since the reactions are difficult to simulate experimentally under reservoir conditions, due to their slow rates of reaction (Amrani et al, 2008;Anderson & Thom, 2008;Ding et al, 2008, 2009, Yue et al, 2005, natural CO 2 -H 2 S reservoirs form ideal natural analogues for CO 2 -H 2 S cosequestration (Allis et al, 2001;Bickle et al, 2013;Kaszuba et al, 2011).…”

Sulfate Sources of Thermal Sulfate Reduction (TSR) in the Permian Changxing and Triassic Feixianguan Formations, Northeastern Sichuan Basin, China

“…However, there is no research on the use of both methods simultaneously to remove pyrite from solid bitumen, nor has an experiment been conducted to compare the two methods and to determine which method is more effective. The relatively high concentration of H 2 S (5-20%) in the Permian Changxing (P 2 c) and Triassic Feixianguan (T 1 f) Formations in the northeastern part of the Sichuan Basin has been concluded to be from TSR [4,6,[17][18][19], whereas sulfur-rich solid bitumen has been found in other gas reservoirs [6,14,20,21]. The H 2 S concentrations of the gas reservoirs in the eastern part of the Kaijiang-Liangping (K-L) trough (see detailed information in the background section) are higher than those of the gas reservoirs in the western part of the K-L trough [6].…”

Origin of dolomite in the third member of Feixianguan Formation (Lower Triassic) in the Jiannan area, Sichuan Basin, China

“…1A) where massive dolomites are thick and pervasive. For example, the dolostone in the Puguang gas field, with thickness up to 250 m, has fabric-retentive textures with intercrystal pores, intraparticle pores, interparticle pores and vuggy pores as the major pore types (Zhang et al, 2011;Hao et al, 2015). Instead, the dolostone in the Jiannan area is very thin.…”