Solution : https://service.sap.com/sap/support/notes/530176 (SAP Service marketplace login required)
Key words : 
wide rangeof industry-specific functions, mysap oil&gas offers customers, 1000 l15mardo1 1000 l15       800  kg       900  l12post movement, 0  l15         -20 kg          10 l12the system, special check orzero logic, materials management - inventory management, enter 'xx-rc-nn', additional stock tables extending, 1000 l15      820  kg      890  l12leads, symptom xx-rc-
Related Notes : 
       
| 652834 | Additional Quantity Handling: Manual Changes and Effects | 
| 546569 | FAQ : HPM - Hydrocarbon Product Management | 
| 308021 | FAQ: Tank/Silo management | 
| 212707 | Reports to analyze and correct stock qties in IS-Oil systems |