11. Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Realized and unrealized gains and losses on derivative instruments

	Six Months Ended
	June 30, 2016
Realized gain (loss) on derivatives:
Crude oil fixed price swaps	$	922,872
Crude oil collars		120,154
Realized loss on derivatives, net	$	1,043,026
Gain (loss) on the mark-to-market of derivatives:
Crude oil fixed price swaps	$	(4,157,491	)
Crude oil collars		(131,245	)
Gain (loss) on the mark-to-market of derivatives, net	$	(4,288,736	)