ASSET RETIREMENT OBLIGATIONS (Details 1) - USD ($)	6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jul. 31, 2017
Assumptions Used For ARO Estimates [Line Items]
Undiscounted amount of estimated cash flows	$ 7,275,504		$ 7,098,581
Minimum [Member]
Assumptions Used For ARO Estimates [Line Items]
Payable in years	5 years	5 years
Inflation rate	1.37%	1.37%
Discount rate	5.48%	5.48%
Maximum [Member]
Assumptions Used For ARO Estimates [Line Items]
Payable in years	17 years	17 years
Inflation rate	2.14%	2.14%
Discount rate	6.40%	6.40%