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Summary of Significant Accounting Policies - Schedule of Revenue by Major Customers by Reporting Segments (Details)	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Revenues, percentage	100.00%	100.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Eni S.P.A [Member]
Revenues, percentage	22.00%	10.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | EGP [Member]
Revenues, percentage	61.00%	72.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Other [Member]
Revenues, percentage	17.00%	18.00%

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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