Natural Gas Price?, page-2

While there are other posters that can give a much more comprehensive answer to your question, here is a summary.
WPL production is about 85% gas and 15% oil and condensates. so the change in oil price will have a direct impact on about 15% of WPL's revenue. 
On the gas side, WPL sells both on contracts and spot. About 75% of LNG sales are on long term contracts with the price of gas linked to a 3 month trailing POO. About 20% of sales are spot (linked to the chart you are seeing) and about 5% is on short term contracts and I suspect that pricing is a lot closer related to the POO.

So, when the POO drops, WPL should see a reduction in revenue in the following qtr for long term gas contracts.

As the market is looking ahead, it is discounting WPL sp.

HT1