X0306 4 2021-04-13 0 0001486159 Oasis Petroleum Inc. OAS 0001705952 Brown Daniel E 1001 FANNIN STREET SUITE 1500 HOUSTON TX 77002 1 1 0 0 Chief Executive Officer Common Stock 2021-04-13 4 A 0 43975 A 43975 D Performance Share Units 2021-04-13 4 A 0 37292 0.00 A Common Stock 37292 D Performance Share Units 2021-04-13 4 A 0 37292 0.00 A Common Stock 74584 D The Reporting Person was granted 43,795 Restricted Stock Units by the Issuer as compensation pursuant to the Issuer's 2020 Long Term Incentive Plan (the "2020 LTIP"). Each Restricted Stock Unit represents a contingent right to receive one share of the Issuer's common stock, par value $0.01 per share ("Common Stock"). Each Performance Share Unit represents a contingent right to receive a number of shares of Common Stock, ranging from zero to 300% of the target number of shares of Common Stock shown in Table II, depending on the Company's total shareholder return ("TSR") over a three-year measurement period beginning on April 15, 2021. For example, at the measurement dates in the last 12 months of the measurement period, TSR must increase at least (i) 145% to achieve the maximum 300% of target, (ii) 85% to achieve 200% of target, (iii) 25% to achieve 100% of target. However, if at least a 25% increase is not achieved on the measurement dates in the last 12 months of the three-year measurement period, no shares of Common Stock are earned. These Performance Share Units were granted as compensation under the 2020 LTIP. Each Performance Share Unit represents a contingent right to receive a number of shares of Common Stock, ranging from zero to 300% of the target number of shares of Common Stock shown in Table II, depending on the Company's TSR over a four-year measurement period beginning on April 15, 2021. For example, at the measurement dates in the last 12 months of the measurement period, TSR must increase by at least (i) 145% to achieve the maximum 300% of target, (ii) 85% to achieve 200% of target, (iii) 25% to achieve 100% of target. However, if at least 25% increase is not achieved on the measurement dates in the last 12 months of the four-year measurement period, no shares of Common Stock are earned. These Performance Share Units were granted as compensation under the 2020 LTIP. /s/ Nickolas J. Lorentzatos, as attorney-in-fact 2021-04-16