(Sharecast News) - Riverstone Energy on Friday confirmed that it has invested $100m Argentine oil and gas gathering and processing-focused midstream company, Aleph Midstream S.A. Riverstone's investment comes alongside $3m from other investors associated with Riverstone. This includes $54m from Southern Cross Group, $45m from Vista Oil & Gas and approximately $3m from the Aleph and Vista management teams, for a total commitment of approximately $205m, which is expected to be deployed over the next 24 months.The FTSE 250 company said that Aleph will become the first midstream player focused on providing gathering, processing and evacuation services for oil and gas production of Argentina's "world class" Vaca Muerta shale play.Its new investee plans to start funding the construction of infrastructure upon closing of the transaction, which is expected to take place in July, and intends to begin providing certain midstream services from January 2020 onwards.Riverstone said Aleph is also currently negotiating credit facilities which it expects to close within the third quarter of 2019.