James P. Henderson - 01 Jul 2022 Form 4 Insider Report for WHITING PETROLEUM CORP

Footnote F1

This Form 4 reports securities disposed of in connection with the Agreement and Plan of Merger, dated March 7, 2022 (as it may be amended or supplemented from time to time, the "Merger Agreement"), by and among Oasis Petroleum Inc., a Delaware corporation ("Oasis"), Ohm Merger Sub Inc., a Delaware corporation and a wholly owned subsidiary of Oasis ("Merger Sub"), New Ohm LLC, a Delaware limited liability company and a wholly owned subsidiary of Oasis, and Whiting Petroleum Corporation, a Delaware corporation ("Whiting"). Pursuant to the Merger Agreement, on July 1, 2022 (the "Company Merger Effective Time"), Merger Sub merged with and into Whiting (the "Company Merger"), with Whiting continuing its existence as the surviving corporation following the Company Merger as a direct, wholly owned subsidiary of Oasis.

Footnote F2

A percentage of the remaining restricted stock unit ("RSU") award granted to the Reporting Person in September 2020 vested immediately prior to the Company Merger Effective Time for shares of Common Stock. Pursuant to the Merger Agreement, any remaining unvested RSUs were assumed by Oasis and converted into the right to receive an RSU of Oasis. The Merger Agreement was filed by Whiting on March 7, 2022, as Exhibit 2.1 to its Current Report on Form 8-K.

Footnote F3

The reported shares were withheld to satisfy the Reporting Person's tax liability in connection with the vesting of the RSUs. No shares were sold.

Footnote F4

Pursuant to the Merger Agreement, each share of Common Stock beneficially owned by the Reporting Person at the Company Merger Effective Time was exchanged for the right to receive 0.5774 shares of common stock, par value $0.01 per share, of Oasis and $6.25 in cash (together, the "Merger Consideration").

Footnote F5

Pursuant to the Merger Agreement, at the Company Merger Effective Time, the performance vesting conditions of each performance stock unit ("PSU") award of Whiting were deemed satisfied based on the greater of (1) the target number of PSUs and (2) achievement of the applicable performance criteria based on a truncated performance period ending immediately prior to the Company Merger Effective Time, with such number of PSUs assumed by Oasis and converted into a right to receive the Merger Consideration upon satisfaction of the original continued service vesting conditions applicable to such PSUs. Based on this performance criteria Whiting expects the PSUs (Absolute) to vest at 200%.