SEGMENT REPORTING (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 43,657,292	$ 46,917,770	$ 82,978,004	$ 88,285,965
Income (loss) from operations	(667,878)	3,023,845	(3,276,269)	2,007,348
Black Oil
Segment Reporting Information [Line Items]
Revenues	37,907,811	38,469,131	70,722,998	70,706,377
Refining & Marketing
Segment Reporting Information [Line Items]
Revenues	3,277,402	4,392,870	6,136,023	10,068,111
Recovery
Segment Reporting Information [Line Items]
Revenues	2,472,079	4,055,769	6,118,983	7,511,477
Operating segments | Black Oil
Segment Reporting Information [Line Items]
Revenues	37,907,811	38,469,131	70,722,998	70,706,377
Income (loss) from operations	125,851	2,969,532	(2,166,354)	2,210,180
Operating segments | Refining & Marketing
Segment Reporting Information [Line Items]
Revenues	3,277,402	4,392,870	6,136,023	10,068,111
Income (loss) from operations	(132,408)	(357,656)	(535,422)	(701,040)
Operating segments | Recovery
Segment Reporting Information [Line Items]
Revenues	2,472,079	4,055,769	6,118,983	7,511,477
Income (loss) from operations	$ (661,321)	$ 411,969	$ (574,493)	$ 498,208