Vista Oil & Gas B de C : 06.25.21 Announcement regarding the sale of working interest in the Coirón Amargo Sur Oeste concession

Vista Oil & Gas announces the sale of its working interest in the Coirón Amargo Sur Oeste

concession

Mexico City, June 25, 2021 - Vista Oil & Gas, S.A.B. de C.V. ("Vista" or the "Company") (NYSE: VIST;

BMV: VISTA) announced today that its subsidiary Vista Oil & Gas Argentina S.A.U. has sold its 10% working interest in the joint venture agreement (the "JV agreement") over the Coirón Amargo Sur Oeste ("CASO") concession to Shell Argentina S.A., a subsidiary of Royal Dutch Shell plc. ("Shell"), for a total consideration of US$21,500,000, payable in the following manner: (i) US$15,000,000 in cash, and (ii) US$6,500,000 as carry for the extension of infrastructure works for the collection and supply of water, which is operated by Shell and supplies Vista's operation.

The Province of Neuquén, by means of Decree 1027/2021, dated June 24, 2021 (the "Decree"), has approved the addendum to the JV agreement, reflecting the new working interests in such JV in accordance with the aforementioned transaction. With the issuance of the Decree all agreed conditions precedent have been fulfilled; therefore, Vista and Shell shall determine a closing date for the transaction, which must take place within the next 5 business days. Once closed, the transaction shall have retroactive effect to April 1, 2021.

The CASO concession holds 16,440 acres in the shale oil window of Vaca Muerta, of which 1,644 acres correspond to Vista's 10% working interest, which will be assigned to Shell at closing. Currently, CASO is under field development, having completed its pilot phase in 2019. Total hydrocarbon production for the year 2020, at Vista's 10% working interest, was 94 boe/d (barrels of oil equivalent per day). Vista's total proved reserves in CASO as of December 31, 2020, were 1.5 MMboe (million barrels of oil equivalent) according to the report prepared by DeGolyer and MacNaughton Corp. dated February 1, 2021.

Forward-Looking Statements

Any statements contained herein or in the attachments hereto regarding Vista that are not historical or current facts are forward-looking statements. These forward-looking statements convey Vista's current expectations or forecasts of future events. Forward-looking statements regarding Vista involve known and unknown risks, uncertainties and other factors that may cause Vista's actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward- looking statements. Certain of these risks and uncertainties are described in the "Risk Factors," "Forward- Looking Statements" and other applicable sections of Vista's prospectus filed with the United States Securities and Exchange Commission ("SEC") and other applicable filings with the SEC and the Mexican National Banking and Securities Commission (Comisión Nacional Bancaria y de Valores).

Enquiries:

Investor Relations: [e-mail]: [phone] Mexico: [phone]