Some of the main criticisms of the buyback contracts include lack of flexibility of cost recovery and in some cases, the NIOC's limited expertise to reverse field decline rates in comparison to the International Oil Company (IOC) that developed the field. The Integrated Petroleum Contract (IPC) will require the IOCs to fulfill Iran's local content requirement, which will be 51% of the contract and transfer of technology. NIOC will set up joint ventures for crude oil and gas production with international companies which will be paid with a share of the output. IPCs will be offered for work on somewhere between 34 and 74 oil fields and could last for the duration of a field's life. In 2013 Iran also announced for the first time since the Iranian Revolution of 1979, the offering of production sharing contracts (PSCs) for the most complicated and difficult projects, such as deep-water wells in the Caspian Sea (the details of which will be revealed in December 2015 in London).