The Woodford is tracked at the sidebar at this link.
From The University of Oklahoma, May 10, 2019: The Woodford Shale in the Marietta Basin (Oklahoma and North Texas).
The Decline Curve Analysis shows average EUR of 90,000 bbl./1000ft lateral; therefore a 5000-foot lateral unbounded well (one section) could produce an average 450,000 bbl. of oil and 1 Bcf of gas. I show that EUR directly correlates with thicker "target intervals" (>80 feet) in the Woodford section and with deeper depth due to higher reservoir pressure support.
It all started with this, from twitter:
I wouldn't have bothered posting but look at this. Apparently, drilling these Maritta Basin wells is costing $16 million and 90 days to drill to a TVD of 16,000 feet. Compare with the Bakken: $7 million or lower; nine days or less with TVDs of around 21,000 feet.
I would assumed it's a time issue. I.e. even though at same depths, the basins were not stuck down there the same amount of time. So even though the stratum are the same age, the Anadarko Woodford was deep longer amount of time. Like if you are comparing cooking pies in two ovens, sans preheat. Same amount of time, same final temp. But one ramped to temp faster and the other took a long time to get to temperature. The pie is going to be affected by the overall time-temp cooking experience, not just the final value.
ReplyDeleteI don't know but it's interesting to compare the EURs, cost of wells, etc, from different basins.
DeleteYou're confusing Measured Depth (MD) and True Vertical Depth (TVD). There are no Bakken wells ANYWHERE that go this deep.
DeleteYou are 1000% correct. Thank you.
DeleteOil tends to get generate based on time/temp. So you starte with kerogen (oil shale, not shale oil) like in Green River. Then you get very little gas, then medium, then light, then ultralight. With more and more gas. And then "wet gas". Then dry gas. It can be more complicated because of transport, traps, etc. But that's the big picture. Deeper gassier, older gassier, and "spent more time deep" is gassier.
ReplyDeleteThank you.
DeleteI somehow stumbled across this post about my Tweet. There's a glaring problem with your comment though. No one is drilling Bakken wells at 16000' TVD. Bakken wells are like 10000' TVD. There is a difference between TVD and MD. TVD is true vertical depth, and most of these marietta wells are like 26- 28k' Measured depth, meaning they go down vertically 16k ft. and then out horizontally another 10k ft. Compare that to the Bakken stuff you speak of that is likely 10k ft down and 10k ft horizontally for a total measured depth of ~20k' deep. Going deeper means more pressure, more steel, and longer time. Hence the additional cost.
ReplyDeleteYou are 1000% correct. Thank you.
Delete