Locate the current mineral deed. If the mineral rights to the land have never been sold separately from the surface, however, there will be no mineral rights deed. In this case, the decedent's real estate deed represents ownership of both the surface and any oil deposits underneath.
Execute a title search at the local land recorder's office to confirm that the current landowner actually owns the oil rights he is purporting to convey, and to confirm that they are not subject to any encumbrance such as a lease, a mortgage or a tax lien. Title searches are performed at the county land records office, usually by property attorneys or title insurance companies. The expenses of a title search count as estate administration expenses and should be paid for by the estate.
Draft a mineral deed. The deed should name the decedent's estate as the grantor and the heir as the grantee. It should also contain a legal description of the oil rights to be transferred. This description should include a description of the surface land -- typically contained in the current real estate deed or mineral deed -- along with a specific description of the rights to be transferred. It should also grant the mineral rights owner the right to enter onto the land and perform whatever acts may be necessary to extract the oil underneath. This will give the heir the right to enter the land and operate the oil well on the surface. The signature line should identify you by name and by title as executor of the decedent's estate.
Prepare the deed in duplicate. Sign and date both copies in the presence of a notary public, and give one copy to the heir.
File the second copy of the deed with the local land recorder's office. If there is a filing fee, pay it out of estate funds and record it as an estate administrative expense.