No, the Administration is not obligated to buy oil for the SPR, and I do not think this Administration will. Granholm’s statements waffling on repurchases is why the Saudis announced production cuts (remember that the “commitment” to repurchase at a given price was made to keep OPEC from cutting in response to the SPR sales).
As a point of reference, the previous Administration proposed buying oil for the SPR as part of the Covid stimulus package, when oil was basically free, and the Democrats refused.