Note 9 - Supplemental Financial Data - Oil and Gas Producing Activities (Unaudited): Summary of Changes Present Value of Estimated Future Net Revenue (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Details
Present value of estimated future net revenue, beginning of year	$ 58,000	$ 120,000
Sales and Transfers of Oil and Gas Produced, Net of Production Costs	(30,000)	(52,000)
Net Increase (Decrease) in Sales and Transfer Prices and Production Costs	(7,000)	(12,000)
Revisions of quantity estimates	(16,000)	(25,000)
Accretion Expense	6,000	12,000
Standardized Measure of Discounted Future Net Cash Flow of Proved Oil and Gas Reserves, Other	12,000	15,000
Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves	$ 23,000	$ 58,000