XML 40 R28.htm IDEA: XBRL DOCUMENT v3.7.0.1
6. Property and Equipment (Tables)
3 Months Ended
Mar. 31, 2017
Property and equipment:  
Property and equipment
    March 31,     December 31,  
    2017     2016  
Property and equipment   $ 128,155     $ 140,547  
Less: Accumulated depreciation and amortization     (109,710 )     (112,128 )
Total property and equipment, net   $ 18,445     $ 28,419  
Depreciation, depletion, and amortization expense
    Three Months Ended  
    March 31,  
    2017     2016  
Depletion of costs for evaluated oil and gas properties (1)   $     $ 2,022,504  
Depreciation and amortization of other property and equipment     3,100       3,885  
Total depreciation, amortization and depletion   $ 3,100     $ 2,026,389