Sunday, January 9, 2011

Natural Gas: The 100 Year Bridge

Google "bridge fuel" and you will see a long list of discussions about natural gas being our bridge fuel to the future. I was using this term about nat gas years ago before it became something of a buzz phrase. Unfortunately, it's not creating the buzz it deserves - yet. Just what do they mean with this "bridge" talk anyway? Well, if you want a literal picture of "the bridge" here it is:

Here we see the cumulative global production charts for crude oil and natural gas up until the early 2000s with the Hubbert calculation for peak and decline. If you add NGL (natural gas liquids) to the natural gas curve, the green line actually forms a pretty even double hump with the oil curve - about 25 years apart. Historically, gas has been a Cinderella byproduct of oil production, but as the geometry of the above chart shows, it is now becoming the belle of the ball as conventional crude passes peak.

Nothing on the earth - solar, wind, batteries, ethanols, or algea - is going to come anywhere near matching the massive scale that natural gas is already providing in the years immediately ahead. This situation alone should cause nat gas to be the #1 alternative fuel consideration. In other countries, it is. But in America, congress and our president are going out of their way to ignore it in their drive to make the USA the global village idiot of energy policy.

I want to look at something that has happened to the bridge above. The chart was made before the advent of shale fracing and the huge reserve increases made from the Marcellus, Haynesville, Fayetteville, Barnett and other shale plays. As a result of this recent development, the 25 year bridge has become what many are calling a 100 year bridge provided to us by natural gas before we have to scale up a fossil fuel replacement team. These plays in North America are only a small part of this reserve addition. Schlumberger and other American drilling giants have developed the drilling method, so it is being put into use here first. But there are many shale areas around the world awaiting development. So globally, it looks as if we may have a big safe bridge ahead of us to develop alternative energy on.

This outlook, however, may wind up being a dangerous illusion. Natural gas drilling and recovery is subject to the same math that oil obeys with regard to net energy discussed in my post Oil: Beyond The Barrel And Over The Cliff. Making a producing horizontal well with intense water fracturing, separation and recovery is a very energy intense way of getting gas energy online compared to the way we used to do it. Even with the old fashioned drilling, we are running up against this EROI wall about now :

This net energy study was done by Jon Friese, a software engineer in Minneapolis as part of his volunteer work with Twin Cities Energy Transition Group. He used Canadian data because they provide much better well data than our energy policy challenged US counterpart does, but by indirect comparison measures, he thinks pretty much the same thing is going on with drilling on the US side of the border. If you consider the "cliff" location to be the 3 to 4 zone of the EROI ratio as shown in my post, this drilling picture has us rushing there in just a few short years. Obviously, we need such a study for the shale drilling, but considering that it is more energy intensive than what is shown, the chart would likely look just as scary.

We have exponential problems we are coming up against long before we reach the end of the 100 year bridge:

Here I graphed what the number of rigs would have to look like on top of the gas production per rig chart as it follows a fitted straight line per past data collected by Baker-Hughes. Just to keep production flat, you have an exponential curve develop as per rig production declines. We will have to come up with new technology and operations that jar us away from this geology induced straight line descent, or we will be forced to punch holes in rock like crazy to meet energy demand. Will shale drilling do that for us?

Despite the vast reserve additions being booked for our natural gas supply, there are real causes for doubt as to whether we will actually see all this energy feasibly produced. Over at the and the Arthur Bermin has an article Shale gas: Abundance or mirage: Why the Marcellus Shale will disappoint expectations where he makes this bearish statement on the nat gas companies:

Shale gas plays in the United States are commercial failures and shareholders in public exploration and production (E&P) companies are the losers. This conclusion falls out of a detailed evaluation of shale-dominated company financial statements and individual well decline curve analyses. Operators have maintained the illusion of success through production and reserve growth subsidized by debt with a corresponding destruction of shareholder equity. Many believe that the high initial rates and cumulative production of shale plays prove their success. What they miss is that production decline rates are so high that, without continuous drilling, overall production would plummet. There is no doubt that the shale gas resource is very large. The concern is that much of it is non-commercial even at price levels that are considerably higher than they are today.
He states that profitability is hard to come by at sub $5 gas, and he is not alone in saying this. An attendee of the Biophysical Economics 2nd International Conference wrote on his blog, about a study of the Barnett Shale made by Bryan Sell comparing a conventional field to the shale field:

Recent studies have shown only 28% of these wells have been profitable, and Sell showed costs per foot drilled in the Barnett at $150, three times conventional well costs. Shale plays also tend to be much deeper than conventional wells, driving up per-well cost. The Marcellus and Haynesville plays are more difficult and deeper than Barnett, and cost per foot drilled is double or more what it is for Barnett.
Sell also had some net energy numbers to report on Barnett:
The EROI went from 84:1 in 2000 to 38:1 in 2007, and overall volume per well had also dropped to half over the same period. This trend suggests another halving in 7 years, a 10% decline rate. Despite initial positive EROI, Barnett will show lower EROI than the conventional PA play in about 10 years time.
If that's the case for all the shales, their EROI chart will look like the one above for conventional gas in just 10 years after they reach the stage of maturity that Barnett is at now - rushing to the edge of the net energy cliff.

Many analysts, including Jim Cramer, have pegged natural gas stocks as a next big thing. But they could be up against a pickle with spending a fortune for oil and other energy input costs to extract a product that is residing at near breakeven pricing with plenty of it on the market already. They may be in a chronic situation where they can mothball capacity to raise the gas price, put a small wave of it on the market until price declines force them back into mothballing again. There is plenty of gas there, but the energy and production costs may be an ongoing dilemma for decades.

I am a great fan of the Pickens Plan for natural gas energy independence for America. And I think natural gas is our best bridge fuel for getting us to the post carbon world. But the bridge may be shorter and shakier for us gas fans than we think.


  1. What about the danger of toxics used in the drilling method of shale gas?
    I refer to the Gasland movie

    1. Anonymous,
      There have always been hazards with recovery of about any natural resource - coal mining, water wells. Nat gas is no different. But about all the problems with gas in drinking water or blowing up houses is from crude well construction - mostly very old wells done before the safe methods done now. If a company does a well this poorly nowadays, they are out of business in a hurry, and they now it.

      The stuff used in the drilling fluid is pretty mild. It's just water and either sand or ceramic proppants that are as safe as sand. The fracking fluid doesn't have to chemically act with the shale, it just has to be the right mix to prop open any cracks that the extreme pressure on the fluid opens up. So, being very mindful of toxin issues, they do this with many of the ingredients used to bake a cake or other foods.

      The real problem with fracking fluid is what to do with it after it does its fracking and comes back up. After being blasted through the rock, it can pick up traces of arsenic and other toxins commonly found in dirt. But
      they isolate and treat this water.

      For a study on this, I refer you to "Extracting natural gas from shale can be done in an environmentally responsible way, says Stanford researcher on government panel"
      (google it). Here is a quote from there:

      "So what about the chemicals in the fracturing fluid?

      Hydraulic fracturing fluid is mainly water, with small amounts of thickening agent added – usually guar, the same thickening agent used in making ice cream. There is also some biocide, to kill bacteria in the water, as well as a little bit of a friction reducer.

      Unfortunately, an act of Congress exempted the gas companies from having to reveal the chemicals in the fluid. I say unfortunate because it has led to unnecessary suspicion and paranoia. Our report recommends that the contents of fracturing fluid be fully disclosed.

      Has hydraulic fracturing caused drinking water contamination?

      There have been fears that hydraulic fracturing fluid injected at depth could reach up into drinking water aquifers. But, the injection is typically done at depths of around 6,000 to 7,000 feet and drinking water is usually pumped from shallow aquifers, no more than one or two hundred feet below the surface. Fracturing fluids have not contaminated any water supply and with that much distance to an aquifer, it is very unlikely they could.

      This said, there are instances where natural gas has been found in drinking water supplies, which is one of the problems that can be caused by poor well construction. If the steel well casing is not fully cemented, gas can leak up around the outside of the casing and contaminate shallow aquifers. In fact, a related problem is that there are a number of aquifers contaminated with natural gas that can be traced to leaking casings of very old wells that predate recent drilling for natural gas by 40 or 50 years.