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The graph below prepared by EOG Resources (using data provided by IHS Energy) illustrates the most important thing you need to know about the North American natural gas market. Decline rates of gas wells have almost doubled over the last 10 years!

Natural gas wells normally produce a their highest rates as soon as they are put into production. Over time the gas flow rates decrease until the revenue stream from the gas production is less than the cost required to maintain production. This is when the wells are shut in or abandoned.

The slope of each line on the graph represents the decline rate. A new natural gas well that produced 1 million cubic feet of natural gas per day (1 MMCF/D) on January 1, 1990 would produce .83 MMCF/D on January 1, 1991. While this well would likely produce natural gas for many decades, each successive year will see less production than the previous one. The greatest declines in natural gas wells typically occur during the first year and then they decrease to a few percent a year. This is illustrated by the ever decreasing slope of the production lines from left to right on the graph.

What is important to realize is that a natural gas well drilled on January 1, 2007 producing 1 MMCF/D will be producing only .68 MMCF/D on January 1, 2008. Increasing decline rates are the direct result of advances in petroleum engineering. Natural gas wells are drilled using methods that cause less damage to the gas bearing reservoir. Then the wells are "fracced", a method that creates fractures in the rock allowing more gas to flow in to the wellbore. Many of today's natural gas wells wouldn't flow any gas at all using drilling techniques from the 1960's. In other words, we can drain the natural gas out of the reservoir in less time using modern technology.

The constructive aspect of increasing decline rates is that exploration companies can recover their costs more quickly allowing them to reinvest their capital into more drilling. Unfortunately when drilling costs increase significantly or the natural gas prices are low, exploration activity naturally decreases. When decline rates were lower, it was relatively easy to "catch up" and create new natural gas supplies to replace production. The current situation where natural gas price declines are higher creates an "exploration treadmill" where more drilling is required to maintain current production levels. We are coming off of a period of low natural gas prices and lowered exploration budgets. A small increase in natural gas demand will create a volatile situation where prices spike and the industry struggles to replace natural gas reserves that are declining at ever increasing rates.

Other factors that weight heavily on the natural gas supply picture include an increasing reliance on unconventional natural gas sources and the trend towards lower natural gas production per well.

gas_production_history_decline

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This article has 5 comments:

  •  
    Ah yes, gas from shale depletes quickly. But not so for coal bed methane. It is present at many times greater amounts disolved in the coal, releases slower and actually increases its release rate as the well ages.
    2007 Jun 15 02:32 PM | Link | Reply
  •  
    I believe your engineering on the coalbed methane (CBM) is off a bit. Yes, the rate increase initially as the coal de-waters and the pressure is reduced. However, CBM wells also experience hyperbolic decline like shale gas wells and eventually decline to a very small flow rate. Now, that flow rate will last for a long time, but it will be very very low. The plot shown in the EOG study includes CBM wells, a lot of them as CBM has been a major producing source for many years. BP, ConocoPhillips and Burlington (now part of COP) have been producing CBM in the San Juan basin for years. But the wells have high decline rates too. Get your reservoir engineering straight. Natural Gas is in tight supply and the land owners fight like hell to keep us from drilling for it. I've worked 3 projects involving CBM and only one of them has been economical. The others were fraught with delays and rapid cost increases due to land owner and greenie weenie fights against us.
    2007 Jun 16 03:58 PM | Link | Reply
  •  
    Why would an investor build a house in someones backyard who has the authority to say, "get out now?" And they have guns and cannons and own the country "ta-boot?"
    Smart? I don't think so!

    Howard Denny, Springfield, Missouri
    2007 Jun 16 02:02 AM | Link | Reply
  •  
    This comment was intended to follow (KRY) in Venezuala on another blog. I regret the error.

    Mr. Denny
    2007 Jun 16 02:10 AM | Link | Reply
  •  
    This decline worries me a lot. But I guess the American continent will survive... There's Canada, the US, Venezuela with immense reserves... And not much political conflict around gas..

    But how about Europe?
    It depends almost exclusively on Russia's gas. And when Putin stops it, the whole of Europe remains without gas.
    The bad thing in this whole story is that the pipeline goes through the Ukraine and when the Russians have "bad relations" with the Ukrainians, they just use the "political tap" (they stop the gas)... And the gas travelling through the Ukraine won't reach the countries around, nor the faraway tips of Europe, such as Portugal and Greece...

    This gas thing is just as tragical as the oil reserve depletion!
    Jan 07 04:22 AM | Link | Reply