The president gave the directive at a meeting with members of the Independent Petroleum Producers Association in the Presidential Villa, Abuja.
He commended their determination to increase the participation of Nigerians in the country's oil industry and promised to do all within his powers to address the challenges in the sector.
President Buhari assured all the indigenous companies operating in Nigeria's oil and gas sector of the full support and protection of his administration.
"We have the manpower for a more effective participation in our oil industry. We will give you all possible encouragement.
"You certainly won't be ignored under my leadership," President Buhari told members of the association which represented about 20 Nigerian companies operating mainly on onshore fields.
The president particularly assured the Nigerian oil producers that the present administration would take appropriate actions to maintain and enhance security in their areas of operation.
According to him, efficient security will help to lower production costs which has become unnecessarily high in the country.
Austin Avuru, who spoke on behalf of the Nigerian oil producers, enumerated the challenges currently being faced by the group such as security and the funding of joint ventures with the NNPC.
He said the indigenous oil producers were already making significant contributions to the development of the Nigerian economy and could do more with the support of the present administration.
Avuru later told State House Correspondents that the Independent Petroleum Producers Group (IPPG) had the capacity to deliver 1.2 million barrels of refined oil daily to meet domestic consumption requirement of the nation by the year 2020.
According to him, this will be achieved with the construction of indigenous refineries.
He explained that with other companies coming up with smaller refineries and in partnership with the NNPC, the group was confident that it would meet the target of 1.2 million barrels of refined oil daily.
He further said that the group had, in the past five years, invested nine billion dollars in the oil and gas sector and also made over one billion dollars each year in work programme investment in the sector.
According to him, the group is looking at the segment of the industry that is going to become a very critical partner to government, particularly in the delivery of natural gas and other products into the domestic economy.