Estimated Ultimate Recovery (EUR) Study of 5,000 Marcellus Shale Wells in Pennsylvania. February 2018 Update

Gary S. Swindell, P.E., Consulting Petroleum Engineer, Dallas, Texas

http://gswindell.com Copyright 2018, Gary S. Swindell.

Summary

This study summarizes the results of an updated and expanded evaluation of the estimated ultimate recovery (EUR) for all

horizontal Marcellus Shale completions from 2008 through 2014 in Pennsylvania. Individual well rate vs. time plots using

publically available production data through June 2017 were used to forecast the EUR of 4,936 wells. The primary objective

was to determine the distribution of EUR. Although data is also available for the 2015-2017 well completions, the decline

behavior is not believed to be sufficiently established for reliable projections.

For 4,936 horizontal wells with enough history to forecast a decline profile, the estimated ultimate recovery across the whole

state averages 6.2 billion cubic feet equivalent (Bcfe) per well with a median of 5.0 Bcfe. The results vary considerably by

region – in six counties in the Northeast part of Pennsylvania, the average is 7.2 Bcfe per well and in Wyoming County the

mean EUR is 12 Bcfe. In that Northeast region there are a number of wells exceeding 20 Bcfe EUR. (Lease condensate

was converted to an equivalent gas volume using a price ratio of 20 thousand cubic feet (Mcf) per barrel).

The data shows that apparent operational changes across the area, primarily added take-away capacity and compression, have

significantly improved well performance since the last study in early 2016. Furthermore, many wells have shown more

hyperbolic behavior than forecast in the earlier studies.

A regional breakdown, dividing the state into six areas, Northeast, Northwest, West Central, Mountain, Green-Fayette, and

Washington, was made to analyze well performance in a more local way. (Fig. 3 in the appendix shows the location of the

wells in the study and the regional divisions.)

Charts and tables are used to show the results rather than a paragraph format.

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Fig. 1 – Total Pennsylvania Marcellus gas production – vintaged by year.

Fig 2. Pennsylvania Marcellus Horizontal Well Count.

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7000

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Pennsylvania Marcellus Producing WellsVintaged by year of first production

By comparison, Texas active gas well

count is 70,000

Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 3

Summary of Projected EUR by County

Number of

Study wells County

Average EUR

- BCFe per

Well

Avg Gas Cum

Prod ~8/2017 -

MCF

35 ALLEGHENY 4.98 3,137,435

42 ARMSTRONG 4.49 2,144,871

2 BEAVER 3.76 2,331,868

6 BLAIR 1.15 598,714

753 BRADFORD 7.71 4,169,130

180 BUTLER 4.96 1,859,820

10 CAMERON 1.61 938,401

8 CENTRE 2.26 1,333,290

9 CLARION 2.58 1,156,238

74 CLEARFIELD 1.95 1,145,644

44 CLINTON 3.37 2,014,928

30 ELK 3.12 1,583,605

114 FAYETTE 3.50 1,873,406

4 FOREST 0.92 414,056

452 GREENE 6.30 3,623,124

1 HUNTINGDON 0.62 435,314

21 INDIANA 2.66 1,620,088

22 JEFFERSON 3.33 1,406,866

4 LAWRENCE 2.25 1,164,369

651 LYCOMING 5.55 3,238,274

35 MC KEAN 2.63 1,468,163

1 MERCER 1.44 760,990

29 POTTER 2.79 1,515,148

10 SOMERSET 1.86 1,213,625

47 SULLIVAN 11.52 5,587,276

712 SUSQUEHANNA 9.20 5,378,011

500 TIOGA 4.04 2,323,474

1 VENANGO 1.22 668,327

824 WASHINGTON 5.28 2,374,948

170 WESTMORELAND 4.02 2,303,156

145 WYOMING 11.70 6,299,625

4 Gary S. Swindell, Petroleum Engineering – Marcellus EUR Study 2018

Fig. 3 – The wells and the regions used in the study.

Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 5

NORTHEAST REGION – Bradford, Lycoming, Sullivan, Susquehanna, Tioga, Wyoming counties

NORTHWEST REGION – Cameron, Elk, Forest, McKean and Potter counties

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WEST CENTRAL REGION – Allegheny, Armstrong, Beaver, Butler, Clarion, Indiana, Jefferson, Westmoreland

GREEN-FAYETTE REGION – Greene and Fayette counties

Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 7

WASHINGTON COUNTY

MOUNTAIN REGION – Blair, Centre, Clearfield, Clinton, Somerset counties

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Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 9

10 Gary S. Swindell, Petroleum Engineering – Marcellus EUR Study 2018

Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 11

For about 2,200 wells of the almost 5,000 wells in the study there was readily available perforation information. The perforated interval was used as a proxy for horizontal length. Correlations of EUR to this “horizontal length” proxy are below by region.

12 Gary S. Swindell, Petroleum Engineering – Marcellus EUR Study 2018

For about 2,200 wells of the almost 5,000 wells in the study there was readily available perforation information. The perforated interval was used as a proxy for horizontal length. Correlations of EUR to this “horizontal length “ proxy are below by region.

Gary S. Swindell, Petroleum Engineering – Marcellus Study 2018 13

For about 2,200 wells of the almost 5,000 wells in the study there was readily available perforation information. The perforated interval was used as a proxy for horizontal length. Correlations of EUR to this “horizontal length” proxy are below by region.

14 Gary S. Swindell, Petroleum Engineering – Marcellus EUR Study 2018

For about 2,200 wells of the almost 5,000 wells in the study there was readily available perforation information. The perforated interval was used as a proxy for horizontal length. Correlations of EUR to this “horizontal length” proxy are below by region.