7. Income Tax (Details 2) (USD $)	Sep. 30, 2014	Mar. 31, 2014
Deferred tax assets:
Statutory depletion carry-forward	$ 2,466,000	$ 2,190,000
Net operating loss carry-forward	14,000	0
Other accruals	67,000	103,000
Allowance for doubtful accounts	5,000	5,000
Gross deferred tax assets	2,552,000	2,298,000
Deferred tax liabilities:
Depletion, depreciation and intangible drilling costs	(7,454,000)	(6,784,000)
Gross deferred tax liabilities	(7,454,000)	(6,784,000)
Deferred tax liabilities, net	$ (4,902,000)	$ (4,486,000)