Clariant’s H2S Management and Sequestration Tech for the Pre-salt
Clariant, a global provider of specialty chemicals and solutions for the oil and gas industry, is has been applying its H2S Risk Management System in selected pre-salt plays offshore Brazil. The novel system encompasses the provision and management of specialty chemicals for both subsea activities (liquid H2S scavengers injected into wells) and offshore topside natural gas processing (removal of hydrogen sulfide residues using a solid adsorbent), including the entire onshore and offshore product delivery logistics and managing the removal and disposal of residues generated during the process. The system was developed by Clariant’s research centers in Brazil: the Deepwater Center of Excellence, located in Rio de Janeiro, which operates in conjunction with Clariant’s other Deepwater Centers of Excellence, in Houston, Texas, USA and Aberdeen, UK; and the Catalyst R&D Laboratory located in Suzano, São Paulo, Brazil, which has a specialized team dedicated to developing new generations of catalysts for the oil and gas industry. Both research centers in Brazil also operate in conjunction with Clariant’s new Innovation Center, which was opened in October 2013 in Frankfurt, Germany.
The presence of hydrogen sulfide in the pre-salt reservoirs, as well as the logistical challenges posed by the distance offshore, which may exceed 300km and the restricted space on the platforms to store chemical solutions, are some of the factors that increase the complexity of offshore operations in ultra-deep waters. H2S, which is water-soluble and is present in several pre-salt fields, is highly toxic and impedes the integrity of offshore units. Clariant developed an integrated chemical solutions logistics and application system that meets the demands of H2S removal in two stages. The first stage injects liquid H2S scavengers into the wells so that cleaner hydrocarbon fluid arrives topside. The second stage uses a catalyst (a solid adsorbent) on the offshore natural gas processing plant to purify the gas and eliminate H2S residues, given that the gas cannot be transported to an onshore facility if it contains such impurities.