This chart shows why statisticians don't like seeing two vertical scales. The top chart on the right is roughly the same as the original. The bottom right chart compresses the vertical scale so each unit of length represents twice as many dollars as before. This small manipulation effectively halves the slope of the line and so the growth appears less pronounced in the bottom chart. But there is no reason to pick one over the other: they plot the same data.
Observe also that the criss-crossings between the blue and red lines are artificial, as they disappear from the bottom chart which plots the same data.
Finally, a scatter plot is better able to show the inter-relationship between oil price and capital expenditure.