Annual report pursuant to Section 13 and 15(d)

ASSET RETIREMENT OBLIGATION (Details)

v3.10.0.1
ASSET RETIREMENT OBLIGATION (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Asset Retirement Obligation [Line Items]      
Balance $ 9,055,697 $ 7,957,035 $ 7,401,950
Liabilities acquired 2,571,549    
Liabilities incurred 1,311,956 1,297,289 308,509
Liabilities settled (577,824) (766,595) (240,606)
Revision of estimate [1] 87,960    
Accretion expense 606,459 567,968 487,182
Balance $ 13,055,797 $ 9,055,697 $ 7,957,035
[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.