http://www.seipub.org/des/RSS.aspxen-US2017-02<p class="abstract">Hydrolysis of Pyrite: a Possible Pathway for Generation of High Concentrations of H2S Gas in Deep-buried Reservoirs?</p><ul><li>Pages 1-8</li><li>Author Kangle DingYan Li</li><li>Abstract Sulfates are conventionally regarded as the main sulfur source for H2S gas in sedimentary basins. In recent years, however, some theoretical insights and laboratory experiments indicate that accumulation of H2S in carbonate gas reservoirs may be associated with pyrite. In this paper, thermodynamic analysis and simulation experiments on the interactions between pyrite and water were carried out to investigate the possibility of pyrite hydrolysis in diagenetic environments. The results show that hydrolysis of pyrite possibly takes place above 275 oC. When temperature is above 425 oC, the reaction can proceed spontaneously. The temperature range favoring the occurrence of pyrite hydrolysis is far higher than that for typical oil and gas reservoirs. Thermodynamically pH has negligible influence on the formation of H2S during hydrolysis of pyrite in sedimentary basins. The results of our simulation experiments strongly imply that a small amount of pyrrhotite (FeS1.13) was formed during pyrite decomposition. Nevertheless, significant hydrolysis of pyrite did not occur under closed experimental conditions. Water may not act as an important hydrogen source for H2S generation in a typical natural gas reservoir.</li></ul>http://www.seipub.org/PaperInfo.aspx?ID=36235Development in Earth Sciencehttp://www.seipub.org/PaperInfo.aspx?ID=36235