With oil prices now at $100+ per barrel, companies are revisiting older wells that were shut down when it was economically unfeasible to produce oil from them. Many of these wells are located in southern California:

Independent producers and major conglomerates alike are reinvesting millions in these mature wells, using expensive new technology and drilling techniques to eke every last drop out of fields long past their prime ---- and often in the middle of suburbia.

In this instance, Terra Exploration & Production Co. believes that up to 2 billion barrels of oil remain hidden beneath Signal Hill, once nicknamed "Porcupine Hill" for its crown of oil derricks before developers planted gated communities and strip malls.

"A lot of these wells have been sitting idle for many years," said Mick Conner, who hopes to increase daily production on his half-dozen wells. "If we can take a 10-barrel well and make it a 20-barrel well, it becomes very profitable for us."

In California, some of the least profitable and old wells ---- so-called "stripper" wells ---- are clustered in a dense urban environment, tucked between malls, gas stations and homes. They are the legacy of a turn-of-the-century oil boom that quickly faded with the discovery of oil in Texas and the depletion of the easiest reserves.

But the move to boost production on these aging oil fields has also inspired bitter protests from some homeowners, some of whom live just a few dozen feet from active wells. Many do not own the mineral rights under their land or moved in long after the original well was built.

If I had a lot of free time on my hands, and still lived back in California, I would probably write a book on California's oil history. It's an interesting topic, but I can't imagine it would be much of a bestseller. At least my parents would buy a few copies.