State officials are negotiating modifications of state oil and gas royalty terms on offshore Beaufort Sea leases held by Eni US Operating Inc. Most of Eni's leases on the project now require a 16.6 percent royalty on gross production revenues. Some leases are 12.5 percent gross royalty with an additional 30 percent share of net profits paid to the state. Eni is proposing to develop heavy oil from one shallow reservoir interval and conventional light oil from a deeper reservoir section in the project, which underlies shallow waters offshore the producing Kuparuk River field on the North Slope. Eni has told state officials it hopes to secure corporate approval for development by the end of 2007 and have Nikaitchuq in production in 2009. On Oct.