ROCKMAN wrote:DC – ...[snip]
I hesitate to forecast the change in EUR. The problem is that wells drilled in 2 years will be done differently than wells drilled 3 years ago. Besides having longer laterals and more frac stages some may be drilled on tighter spacings. Longer laterals are one way to offset the lower production potential of the less sweet spots. So some of these future wells might have EUR’s comparable to earlier sweeter wells. But it will come at a higher costs. Two wells might project to have the same EUR’s but one may cost 50% more to drill than the other so it diminishes it’s economic significance even while delivering the same amount of oil.
And for the love of Dog stop making projections down to the tenth of a percent. Remember what we geologists say 2 + 2 is equal: somewhere between 3 and 5. LOL
Hi Rockman,
I misunderstood the last part of this post, I thought you were referring to URR predictions of 5.2 BBO, but I think you were referring to the 12.4 %/a decrease in EUR and, I agree, lets call it 12 % or between 10 and 15 % if you prefer.
I do these models in a two stage fashion, first I attempt to model TRR by assuming only that EUR decreases at some future point in time at a constant yearly rate, I adjust the rate of decrease of EUR to match the mean TRR estimate of the USGS (for the Bakken) and double the USGS estimate for the EFS (TRR=1.75 BB0) because they doubled the Bakken/Three Forks estimate in their recent update so I assume they might do the same for the EFS at some future date.
In the second stage I try to estimate economically recoverable resources (ERR) based on the EIA reference oil price scenario, NPV based on your suggestions and figuring in OPEX, transport costs, financial costs and well completion costs. I assume well completion costs will fall to $7 million per well by late 2015 and that by this time the optimum lateral length and number of frac stages has been established and that any attempt to increase lateral length or number of frac stages would only decrease the profitability of the well due to the increased well costs. (If NPV12.5 is $10 million and well completion cost increases from $7 million to $10 million, we have reduced our profits to zero.)
So I am not looking for you to predict that well EUR will decrease by 12.8 %/ year, I am looking for guidance that well EUR is likely to decrease at between x and y % per year if real well costs remain fixed and the number of wells added per year also remains fixed ( a thought experiment of sorts). Once I have this guess, then the number of wells added per year is adjusted so that it remains profitable to produce oil, as EUR decreases the number of wells added per year decreases and this reduces the rate of decrease of EUR for new wells.
Under the scenario that you propose (longer lateral lengths and more frack stages), I would need to guess at the increased well costs which might result in order to attempt to model economically recoverable resources. In fact if things play out as you suggest, (and I would say that your guess would be much better than mine) would no decrease in EUR make sense? If so, what sort of increase in well costs per year (in real dollars adjusted for inflation) makes sense? A range is fine, maybe10-20%/a increase in well completion costs, if EUR decreases from 10% to 0 %? I was trying to keep the model doable, I am fully aware that no model can fully capture the complexity of the real world. I would like to create a low and high scenario to attempt to bracket the possible future output.
I forgot to mention the tighter spacings, though I think this would tend to offset the longer laterals and greater number of frack stages, though it could increase the potential number of new wells, this is another variable which I have fixed on the assumption that the optimum configuration has been established in plays such as the Bakken and the Eagle Ford.
DC