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Shale Webinar Series: The Utica Reservoir

Webinar Date: April 24, 2013

Current Activity

 There are 616 Utica wells permitted and 305 Utica wells drilled to date (as of April 20, 

2013).

 Recently, large operators are selling off their Utica acreage to small companies (e.g., 

Gulfport Energy Corporation, PDC Energy, Inc.), so that the large companies can pursue

more economically attractive formations in the U.S. 

 There are currently 33 rigs drilling the Utica. Most of these rigs were mobilized from the 

Marcellus when gas prices decreased in winter 2012. Arthur (2013) also provided link to 

Baker Hughes rig count website, which includes locations for all active rigs in the 

country.

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Table 1 summarizes the location of all active U.S. drilling rigs by 

basin/formation and resource type.

Table 1. Active Oil and Gas Rig Counts

Resource Typea Basin/Formation

Number of Active Rigs

Gas Oil Other Total

Shale oil/gas Woodford/Cana 17 32 49

Barnett 20 12 32

Dj-Niobrara 14 28 42

Eagle Ford 30 201 1 232

Fayetteville 13 13

Haynesville 33 2 35

Marcellus 80 80

Utica 5 28 33

Tight oil/gas Granite Wash 24 46 70

Mississippian 1 76 77

Shale oil/gas and 

potentially other 

types of resourcesb

Permian 16 454 470

Williston 1 184 185

Unknownb Other 100 339 5 444

Grand Total 354 1,402 6 1,762

a—Baker Hughes (2013) reported a mixture of basins and formations in a single field. ERG 

categorized the reported basin or formation into a resource type when possible but was not able to 

distinguish resource type for all of them (e.g., Williston, Permian).

b—May include tight oil/gas, conventional oil/gas, or coalbed methane.

Source: Baker Hughes, 2013.

Utica Geology and Location

 Utica underlies the majority of Marcellus but not all of the formation will yield economic 

wells. The “sweet spot” for commercial production from the Utica is eastern Ohio and 

Western Pennsylvania. Commercial viability depends on:

 

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Available online at: http://gis.bakerhughesdirect.com/RigCounts/default2.aspx. 
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o Thermal maturity – The formation must be in the “oil and gas window” in terms 

of thermal maturity.2Figure 1 shows the Utica formation in terms of its thermal 

maturity. Note that approximately half of the geographical area of the Utica is 

overmature or immature and is not expected to be economical.

o Shale thickness – The formation must be of sufficient thickness to allow

production from horizontally fractured wells. Figure 2 shows the thickness of the 

Utica Shale. In general, any thickness greater than 100 feet is feasible to produce 

from but the greater the thickness the better.

o Shale depth – The formation must be shallow enough that the cost of drilling does 

not make the well uneconomical. Figure 3 shows the depth of the Utica shale. 

Some of the thickness parts of the Utica are also located in the deepest parts of the 

formation. 

*Note: All figures are from Arthur (2013).

Figure 1. Thermal Maturity of the Utica Shale

 

2 Thermal maturity is the degree to which a source rock has been exposed to high temperatures. A source rock 

becomes more mature as it is buried deeper into the ground and exposed to higher temperatures. The kerogene 

within the source rock breaks down into shorter carbon chains, decreasing the hydrogen to carbon ratio towards 

methane. Consequently, source rock that has been exposed to high temperatures for a longer period of time tend to 

contain gas (short carbon chains). Source rock that has been exposed to lower temperatures for shorter periods of 

time tend to contain oil (longer carbon chains). Furthermore, if a source rock is exposed to high temperatures for too 

long it becomes “overmature” and falls outside of the oil and gas window.
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Figure 2. Thickness of the Utica Shale

Figure 3. Depth of the Utica Shale.
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 Similar to the Marcellus, the initial Utica wells drilled have produced dry gas in the east 

and wet gas and/or oil in the west due to thermal maturity. Figure 1 shows this trend 

using production data from existing Utica wells.

Source: Arthur, 2013

References

 Arthur, Mike. 2013. The Utica Reservoir. Marcellus Center for Outreach and Research. 

(April 24).

 Baker Hughes. 2013. Interactive Rig Counts. Access May 24, 2013. Available online at: 

http://gis.bakerhughesdirect.com/RigCounts/default2.aspx