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ASSET RETIREMENT OBLIGATION (Tables)
12 Months Ended
Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Asset Retirement Obligations [Table Text Block]
A reconciliation of the asset retirement obligation for the years ended December 31, 2016, 2017 and 2018 is as follows:
 
Balance, December 31, 2015
$
7,401,950
 
Liabilities incurred
 
308,509
 
Liabilities settled
 
(240,606
)
Accretion expense
 
487,182
 
Balance, December 31, 2016
$
7,957,035
 
Liabilities incurred
 
1,297,289
 
Liabilities settled
 
(766,595
)
Accretion expense
 
567,968
 
Balance, December 31, 2017
$
9,055,697
 
Liabilities acquired
 
2,571,549
 
Liabilities incurred
 
1,311,956
 
Liabilities settled
 
(577,824
)
Revision of estimate (1)
 
87,960
 
Accretion expense
 
606,459
 
Balance, December 31, 2018
$
13,055,797
 
 
(1) Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, and estimated remaining useful life of the assets. The 2018 revision of estimates reflect decreases in the estimated remaining useful life of certain assets.