NEW ORLEANS  The details of exactly how the $20 billion fund set up by BP will be distributed to those affected by the oil spill in the Gulf of Mexico, which were made public on Friday, did little to allay worries and suspicions here, drawing instead sharp criticism from several quarters.

Small-business owners, shrimpers, state officials and others affected complained that the rules were too restrictive and were inconsistent with federal law.

At the same time, an internal government study emerged on the potentially high costs of the moratorium on most oil drilling in the gulf. The study, by the Interior Department, estimated a loss of as many as 23,000 jobs if the moratorium continued as planned through Nov. 30.

The study, submitted to a federal court in New Orleans that is considering a legal challenge to the moratorium, also estimated that it would cost more than $10 billion in reduced economic activity and would reduce oil and gas production in the gulf by more than 4 percent over the next three years. Federal royalty revenue would fall by $522 million next year, the report stated.