<P> The two conflicting legal doctrines covering oil and gas extraction are the rule of capture, and the correlative rights doctrine . Which of the doctrines applies in a particular case depends on state law, which varies considerably from state to state, or in the case of the federal offshore zone, on U.S. federal law . </P> <P> The rule of capture provides that an oil producer with a wellbore on his property is allowed to drain oil out from underneath his land--even if some of that oil originated from a neighbor's land, migrating to the oil producer's land through geologic forces or drainage . The rule of capture gives landowners an incentive to pump out oil as quickly as possible by accelerating operations or drilling multiple wells to capture the oil of their neighbors . Such practice may deplete the gas pressure needed to force oil from the ground, which will reduce the amount of oil available for recovery from that reservoir . State law often limits the rule of capture to protect correlative rights of neighboring owners . Government agencies and state oil and gas conservation commissions, such as the Texas Railroad Commission, have developed conservation laws which regulate extraction by individual owners to protect the rights of the mineral owners and to prevent economic and physical waste . </P> <P> Mineral rights may be severed by a deed from the surface rights . Such a condition is called a split estate . Once severed from surface ownership, oil and gas rights may be bought, sold, or transferred, like other real estate property . Ownership in the oil and gas rights for different horizontal layers, or strata, may be further divided and sold to different parties . In some states, severed mineral rights revert to the landowner if the mineral right not exercised for a certain time period . </P> <P> In most states, unless otherwise specified by a deed, the owner of the oil and gas interest is presumed to have the right to occupy as much of the surface property as is reasonably needed to extract the oil and gas, subject to regulations for minimum distances from homes or buildings . Courts have generally held that, without this implied right of access and surface occupancy, ownership of the oil and gas rights would be meaningless . This is called subsurface supremacy . </P>

Who do you call if you strike oil