Iran's newly introduced oil contracts called Iran Petroleum Contract (IPC) will be operational in one month, said Oil Minister Bijan Namdar Zanganeh.
He spoke of the ministry's struggle to push the IPC through, despite efforts in Iran to hinder it, ILNA reported.
Zanganeh said the efforts were made by "those whose interests will be hurt" by the new contracts.
Iran put forward 52 oil and gas development projects in addition to 18 exploration blocks for investment at the Tehran IPC Conference.
The projects include 29 new and currently producing oilfields and 23 gas developments. Onshore fields constitute 34 of the projects. The projects are estimated to be worth more than $30 billion.
IPC is replacing buyback deals. Under a buyback deal, the host government agrees to pay the contractor an agreed price for all volumes of hydrocarbons the contractor produces.
However, under the IPC, National Iranian Oil Company (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.
In the wake of nuclear deal reached last July, Iran received high-ranking officials and corporate executives of major companies including those from Germany, Spain, Austria, Italy and France to discuss new cooperation ventures.