According to the article, there was too much supply of the oil for too little demand. An increase in the supply of the oil resulted in shifting the supply curve to the right from S to S1. Since the demand curve remained unchanged, a right shift in the supply curve resulted in a change in the equilibrium point. The new equilibrium point was the one where there was a lower price and a higher quantity of the oil. A small change in the equilibrium level led to a huge change in the price, this was basically because of the fact that the demand of the oil is price elastic (Esfahani, 2012).
In cases wherein the demand curve is elastic, any change resulting in the rightward shift of the supply curve would certainly result in change of the equilibrium position. The new equilibrium position would be such that it would result in an increase in the price and at the same time increase in the quantity. The change in the quantity would be more than the change in the price in case when the demand curve is more elastic. It could be said that the rise in the quantity is more than the rise in the price.
On the other hand, in cases wherein the demand curve is comparatively inelastic, any kind of change in supply curve which would result in shifting it rightwards would again change the equilibrium position. The new equilibrium position would be such wherein there is a rise in the price and rise in the quantity. However, in this case the rise in the price due to the shift of the supply curve is much more as compared to the rise in the quantity. This could be attributed to the inelasticity of the demand curve.