It was not until the 1990s that efficient methods of artificial lift were discovered which have allowed some of the oil to extracted, but at far higher costs than usual.
This has allowed some of the oil to extracted, but at far higher costs than usual. It was not until the 1990s that efficient methods of artificial lift were discovered.
It was not until the 1990s that efficient methods of artificial lift were discovered. This has allowed some of the oil to extracted, but at far higher costs than usual.
It was not until the 1990s that efficient methods of artificial lift were discovered. This has allowed some of the oil to extracted, but at far higher costs than usual.