Are oil wells being refilled from below?  Almost unexhaustible petroleum abiotic theory.

From "The Deep Hot Biosphere", Thomas Gold.

"When a new oil or gas field is explored, an observation is routinely made of a drop in pressure resulting from a given volume of production. Measurement of this change is used to estimate the total volume accessible to the wellbore. Aggregate worldwide, these estimates of reserves drive petroleum exploration, and to some extent, the economic outlook for industrial nations. But it has turned out that such estimates are nearly always much lower than actual production over the course of many years.. This dire prediction profoundly affected the price of petroleum– and through that, the distribution of wealth among nations.

Under the abiogenic theory, if oil and gas are flowing upward from deep (and thus high pressure) levels, their travels cannot be arrested by any caprock, however competent the rock may be.

No rock has a significant tensile strength, so no rock can hold down a fluid that comes up with a pressure greater than that exerted by the weight of the overburden. A caprock will create a concentration of the fluids below it, but the steady flow rate will eventually be reestablished at a value equal to the flow rate at the deep source. The flow throough a caprock obstruction is thus, like that of a river crossed by a dam. The dam causes a lake to form on the upstream side, but after the lake has filled, the flow rate resumes. The same amoount of water will flow over the dam, as the river carried before tha dam was built.

If oil and gas have indeed come up from below, we can expect a vertical series of deeper reservoirs to be stacked below the producing field. If, now, the uppemost domain has its fluid pressure decreased by production of oil and gas, then the pressure differential accross the crussed layer of low permeability will automatically increase. Transport of fluid through that layer will, therefore, accelerate. The top field will be replenished at a rate given by the leakage from below, when the delicate pressure balance between rock and fluid has been changed. The top field will be drawing on the deepeer reserves that have not been accessed directly. In the course of time, at a slow rate given by creep deformation in the rock, the stepwise pressure pattern will adjust its levels to the new pressure situation.

In other words, without drilling any deeper, we can nevertheless tap into the deeper reserves that may well be much larger than the reservoir under production.

The phenomenon of petroleum reservoirs that seem to refill themselves is widely reported, notably in theMiddle East and along the U.S. Gulf Coast.

I regard these occurrences as strong evidence for the deepearth gas theory."    (Thomas Gold, 2001, Copernicus Books)

More information in the book "Unexhaustible? Petroleum and Natural Gas", D.Anton, Piriguazu Ediciones.