Sunday, November 10, 2013

Bakken 101 -- A Closer Look At An Early EOG Well; Periods Of Production Variability

Earlier I posted the early EOG Bakken wells. I was curious to see the production history. Below are three periods of production for:
  • 16346, 1,800, EOG, Bartelson 1-3H, s9/26/06, t11/17/06, cum 422K 9/13;
For all periods, these are the columns
PoolDateDaysBBLS OilRunsBBLS WaterMCF ProdMCF SoldVent/Flare

Note: a pump was placed on this well in 2007, so the changes in production below are not related to a pump.

First period in early 2008 shows the decline rate:

BAKKEN6-20083086178900447315703009
BAKKEN5-20083087508403683316903020
BAKKEN4-20083010073110571338351203362
BAKKEN3-20083071546865542267502526
BAKKEN2-2008291066110685564374603601
BAKKEN1-2008311213612223621426204107
BAKKEN12-20073112749129604445104296

This next period is late 2010 going into early 2011. There is a sundry report received in late 2010 suggesting that EOG was going to "clean out" frack sand from the well.

BAKKEN4-201129259325531991757154369
BAKKEN3-20113130283053242184816930
BAKKEN2-20112831533153238172315840
BAKKEN1-20112223842359582123111220
BAKKEN12-20100000000
BAKKEN11-2010265986471143682710
BAKKEN10-20102815701439160149213680
BAKKEN9-20103026202619324268025310

Finally, the third period that caught my eye, late last year. I did not see any sundry reports that might account for the production increase.

BAKKEN1-20133126942682493129311430
BAKKEN12-20123129252915909140212620
BAKKEN11-20123049449444373051680
BAKKEN10-20122328532744271402813
BAKKEN9-20123035633445142771380
BAKKEN8-20122543949928025714620
BAKKEN7-20123122122187310327402435151
BAKKEN6-201230290329189492848267425

By the way: note that some flaring occurred during this period. There are at least two reasons that flaring occurs even if the well is hooked up to a natural gas gathering and processing system: a) the natural gas gathering / processing plant is saturated; and/or, b) the natural gas processing plant is "down" for routine maintenance. It is my understanding that oil companies are allowed flaring under such conditions. The only way to completely eliminate flaring when the processing plant is saturated/undergoing maintenance, is to shut in the well. There is no guarantee that a shut-in well will return to its former glory; shutting down a well, even temporarily, I am led to understand, could damage the well significantly.

2 comments:

  1. Dear Bruce,

    Thank you for pulling this information together...I was curious about what kind of production can be expected from these type of wells and how the rate declines over time. I know that reserves are very dependent on where the company holds acreage. I appreciate your excellent blog site. Patty P.

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    Replies
    1. Thank you for your kind comments. I never would have thought of going back to an early EOG well had you not asked a question that gave me the idea.

      I found this data very, very interesting. I think folks assume the decline rate is a nice downward curve, but, in fact, with work-overs, the curve could be less smooth than non-experts would expect. For mineral owners, this certainly could result in some surprising nice royalty checks.

      And, this does not include, production variability due to weather, market forces, other operational issues, etc.

      Finally, I assume the decline curve developed by a computer program includes these factors, but the computer programs are, no doubt, conservative in their nature, not taking into account new processes that might be used in re-fracking or re-entry.

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