Why has the BHP share price dropped 7% in 2 weeks?

At the moment, there are quite a few commodities in the BHP portfolio, including copper, iron ore, petroleum and nickel.
However, $BHP Group Ltd (BHP.AU)$ is planning to divest its petroleum business to $Woodside Petroleum Ltd (WPL.AU)$ . At that time, BHP shareholders will receive Woodside shares. In fact, 52% of Woodside shareholders will own the expanded Woodside, while BHP shareholders will own the remaining 48%. But for now, BHP still owns the whole business.
After a rapid climb of the oil price amid the Russian invasion of Ukraine, it has dropped back to under US$110 per barrel.