Please show the necessary steps. I have an idea how to go about it, I want a concrete answer.

interest in a producing Mr. H. Salt purchased an oil well for $45,000. Recoverable oil reserves for the well were estimated at that time at 15,000 bar- rels, of which represented Mr. Salt's share of the reserves. During the subsequent year, Mr. Salt received $12,000 as hisshare of the gross income 1 from the sale of 1000 barrels of oil. From this amount, he had to pay $3000 as his share of the expense of producing the oil. Compute Mr. Salt's depletion allowance for the year