New Wells Reporting: Posted -- Just a Reminder, Nothing New -- The Bakken, North Dakota, USA

Wells reporting IPs or going to DRL status yesterday have been posted, on "New Wells Reporting." Based on IP only (and that's just one data point), one could be disappointed with the Whiting well in Zenith oil field in Stark County.

• 19926, 161, WLL, Roller 21-26TFH, Zenith, Stark County

I don't see the frac report yet at the well file. I may have missed it. 

As you may recall, the some of the highest prices per mineral acre have been in Zenith oil field.

The target for this well was the Three Forks. The seam targeted was about 9 feet below the point at which they entered the Three Forks, if I read the file correctly. I would assume they would try to put the horizontal pretty much in the middle of the targeted formation, making the seam about 20 feet thick.

At this point, I am more interested in the Tyler formation. According to the report, they entered the Tyler at 8,151 feet. They entered the Kibbey Lime at 8,552 feet. If it's as simple as subtracting these two numbers (and I don't know if it is), the Tyler was 400 feet thick in this area.

What follows is beyond my base of understanding but over time the data may make sense. The report stated the following:

• Tyler formation: background gases at the top of the Tyler averaged around 17 units, then increased up to 60 - 196 units at the top of the formation. After around 120 feet, background gases decreased back down and averaged around 17 units through the remainder of the Tyler.
• Kibbey Lime: units averaged 22 - 28.
• Charles: background gases averaged 17 - 73.
• Mission Canyon: averaged 28 - 62 units
• Lodgepole: averaged 22 - 67 units
• Middle Bakken:  averaged 190 units
• Three Forks:  averaged around 150 - 250 units, with connection gases reaching as high as 348 units

For a discussion of what this all means, this is one source; this is probably a better source, but lots of reading. (In fact, the latter source, is quite approachable.)

The volume of gas will increase with effective porosity of the formation; see this long post for background.

Anyway, enough of this. Just some more data points to help me understand the reports.

Definitions:

• Porosity is a measure of how much of a rock is open space. This space can be between grains or within cracks or cavities of the rock.
• Permeability is a measure of the ease with which a fluid (water in this case) can move through a porous rock.

From "World of Earth Science," at eNotes:

Porosity is the ratio of the volume of openings (voids) to the total volume of material. Porosity represents the storage capacity of the geologic material. The primary porosity of a sediment or rock consists of the spaces between the grains that make up that material. The more tightly packed the grains are, the lower the porosity. Using a box of marbles as an example, the internal dimensions of the box would represent the volume of the sample. The space surrounding each of the spherical marbles represents the void space. The porosity of the box of marbles would be determined by dividing the total void space by the total volume of the sample and expressed as a percentage.

The primary porosity of unconsolidated sediments is determined by the shape of the grains and the range of grain sizes present. In poorly sorted sediments, those with a larger range of grain sizes, the finer grains tend to fill the spaces between the larger grains, resulting in lower porosity. Primary porosity can range from less than one percent in crystalline rocks like granite to over 55% in some soils. The porosity of some rock is increased through fractures or solution of the material itself. This is known as secondary porosity.

Permeability is a measure of the ease with which fluids will flow though a porous rock, sediment, or soil. Just as with porosity, the packing, shape, and sorting of granular materials control their permeability. Although a rock may be highly porous, if the voids are not interconnected, then fluids within the closed, isolated pores cannot move. The degree to which pores within the material are interconnected is known as effective porosity. Rocks such as pumice and shale can have high porosity, yet can be nearly impermeable due to the poorly interconnected voids. In contrast, well-sorted sandstone closely replicates the example of a box of marbles cited above. The rounded sand grains provide ample, unrestricted void spaces that are free from smaller grains and are very well linked. Consequently, sandstones of this type have both high porosity and high permeability.