Wednesday, December 4, 2013

A Bakken Case Study

Updates

July 16, 2018: this well had yet another bump in production after new, neighboring wells were fracked, although not as remarkable as before:

PoolDateDaysBBLS OilRunsBBLS WaterMCF ProdMCF SoldVent/Flare
BAKKEN5-20183114091247726797776980
BAKKEN4-20183016811865812798677160
BAKKEN3-201831240925191098724769680
BAKKEN2-201828296629001099668264300
BAKKEN1-201831573654771607816578860
BAKKEN12-201731743780262163873884630
BAKKEN11-2017123293256415154396427816
BAKKEN10-20170000000
BAKKEN9-201721582859622475222691
BAKKEN8-201731108690193459943200
BAKKEN7-201731964109080456042810
BAKKEN6-2017309591037824157386628
BAKKEN5-201731104910561523178288417

 Original Post

After reading an article from an oil analyst, I posted the following on November 28, 2013:
Also:
Wilson said he's noticed many of his fellow operators drilling wells closer and closer together at the major fields in Texas and North Dakota. That makes money quickly and satisfies shareholders. But then the wells start competing with one another for the same oil and decline quickly, he said.
I think the jury is still out but whenever I see comments about decline rates and well spacing it makes me think that some folks still have not adjusted to a new way of thinking: conventional vs unconventional oil. I don't think we've seen evidence in North Dakota that putting wells more closely together is hastening the decline rate.
Hold that thought.

I'm going to walk you through something very, very interesting, a case study that a reader alerted me to. This is worth your time.

First, look at the screen shot of this portion of northeast McKenzie County, sections 4/9-152-96:



The Wisness 1-4H well is file #17345. It is a 640-acre spaced well, fracked/completed/tested in March, 2009, about 4 1/2 years ago. I will show the production numbers later. But the Wisness well is the one you want to keep your eye on -- that's why it's in "green."

Now, look at the three-well pad at the end of the arrow:
  • 24747, 1,511, Newfield, Anderson Federal 152-96-9-4-10H, t8/13; cum 25K 10/13;
  • 24748, 2,095, Newfield, Anderson Federal 152-96-9-4-3H, t8/13; cum 47K 10/13;
  • 24749, 1,915, Newfield, Anderson Federal 152-96-9-4-11H, t8/13; cum 30K 10/13;
Note when they were completed/fracked/tested: August 13, 2013, or in my shorthand: 8/13.

Okay, that's the data you want to keep in mind.

First, the Wisness well, in green, that was drilled back in 2009.

Second, the Anderson Federal 3-well pad that was fracked just a few months ago (8/13).

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Did you "hold that thought," the thought I told you to hold at the beginning of this post? The expert suggesting that as more wells go into the Bakken, they start competing with old wells and the decline rate hastens.

I opined long ago that new fracking near old wells will actually improve production in the old wells. Does this case study support that view? Let's see.

Here is the screenshot of production for the Wisness well:


The Wisness well, #17345 was drilled in 2009. It had a typical Bakken decline rate. But then note what happened in August, 2013. The well was off-line for about half the month (regular readers can probably guess why). Then note the increase in productivity in September and October. This well as producing around 3,000 bbls/month prior to August, 2013. Two months later, production jumped to an astounding 15,000 bbls (or thereabouts). It will be interesting to see the "new" decline rate.

That's good enough for me. But the skeptics in the audience should ask: "Okay, if that's correct, what about another old neighboring well?"

Aren't we lucky? There just happens to be an old well in the immediate area, #17687:
  • 17687, 1,077, Newfield, Gladys 1-9H, t3/09; cum 232 10/13;
Like the Wisness well, the Gladys well was also drilled in 2009.

What did its production look like in the August, 2013, time frame? Here's a screen shot:


Prior to August, 2013, production from this 640-acre spaced well had dropped to less than 2,000 bbls/month. Again, this well was taken off-line for most of August (regular readers can probably guess why). When it came back on line production had come back to nearly 5,000 bbls/month, more than doubling its production prior to the 3-well pad being fracked just to the west.

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Kinda fun for a Wednesday morning, huh? Who knows if there is any cause and effect? Maybe this is all just coincidence. Maybe Newfield is simply changing the choke on the older wells. Maybe a workover rig for the older wells was in play. There are a lot of unknowns. [See first comment and other comments that might follow; readers will provide additional insight and information regarding these wells.]

But the reader who sent this to me suggested that nothing changed with regard to the Wisness well except that a 3-well pad nearby was fracked in August, 2013. What a great way to start a new day in the Bakken.

A huge "thank you" to the reader for alerting me to this. Good luck to all. Something tells me there are more surprises yet to come out of the Bakken.

By the way, did you all notice the cumulative production of that old #17687?  Almost 235,000 bbls and still going strong. This well paid for itself long ago. The bad news: up to 2/3rds of the natural gas that is being produced by this well is being flared. But not all. That means it has a natural gas pipeline hooked up to the well. Look at the screenshot of the NDIC GIS map server again. In the little overview map of North Dakota, you will note a small red speck: that's the location of the area that is zoomed in on. Note where these wells are: northeast McKenzie County where ONEOK has three brand new natural gas processing plants. And even with the three new natural gas processing plants, there is not enough capacity to handle all the natural gas.

Folks who think that operators are simply dragging their feet putting in natural gas pipelines and thus contributing to the problem of flaring might want to take note.

2 comments:

  1. Just a point for this post. There is not any work over documentation in the well file for ether of these wells. When EOG worked over one of my families wells the information was uploaded within a month or so of the work being ddone.

    Ken Schmidt

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    Replies
    1. Thank you for confirming that. I thought the same.

      On another note, my hunch is the geologists could help explain why one older well saw such a huge jump, and the other older well's jump in production was less remarkable. I have some hunches, but I would need to see detailed geologist's reports. But for those who have a layman's understanding of fracking, this all makes sense.

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