Another Peak Oil Cufuffle Part IV
Kilted Green a "peak oil" supporter has some interesting comments regarding "Another Peak Oil Cufuffle". KG queries "why do you think there is so little possibility that the "peak oil" theory might be in the least bit true." We respond... KG's comments in Italics
4. "All oil field extraction profiles show that an oil field's output, bar a few hiccups around the plateau, rises to a peak, levels out and then falls away. This is empirical fact recorded in thousands of actual, real oil fields around the world."
It is true that the production rate from each individual oil well ever drilled has slowly declined over the years. There is a perfectly valid technical reason for this predictable reduction in flow rate.
When oil is extracted, it flows out through pores in the reservoir rock, and then into an open borehole, from there it is transported to surface by a production tubing string.
Tiny quantities of super fine silt may exit through the pores but do not continue to the surface with the oil, tumbling around in the turbulence instead, until the silt very slowly starts to block off the oil producing pore throats.
Overtime this natural "clogging" process causes the initial production rate of the well to slowly decline.
However, this is certainly not an indication that the oil field itself is becoming depleted, as has been proven thousands of times by offset (multi lateral) wells drilled later into the same reservoir.
You constantly need to keep your pressure high, and usually this is acheived later in a wells life as a secondary method by pumping in seawater or steam.
This means the longer you are pumping out of a particular oil well, the percentage of water you pump back up is going to increase. A consequence of "water cut" is that effective production starts declining after a while.
Yes, you can restore a well to its previous flow rate without the water cut effect, but its expensive, time consuming and the well has to be taken out of production to do so.
You first pull the production tubing out of the hole, and then run back in with a drill string, to which is attached an under reamer.
The under reamer will cut away the contaminated face of the well to a depth that will once again expose pristine producing pores.
As the spinning under reamer is slowly lowered, it enlarges the size of the hole, with the "clogging" debris cut away and flushed back to surface by the drilling fluid.
You now have a "new" oil well flowing at its previous rate. This procedure is rarely followed as 99 times out of 100, its cheaper to drill another offset well in the same reservoir.
Empirical evidence can be deceiving, especially from a bias source such as the petrochemical industry. Remember, there are lies, damm lies and then statistics.
Aside from the P.O. theory being Malthusian in nature, "water cut" and "clogging" are two reasons why the very "flow" data that Hubbert's calculations depend can be flawed.
Meanwhile, the recovery rate from existing world oil fields has increased from about 22% in 1980 to 35% today due to new technology and this trend will continue.
In addition, the ratio between proven oil reserves and current production has constantly improved, passing from 20 years in 1948 to 35 years in 1972 and reaching about 40 years in 2003.
These improvements occurred even with low investment in new exploration and upgrading technology due to the low oil prices during the last 20 years. More to come in Part V.
Another Peak Oil Cufuffle
Another Peak Oil Cufuffle Part II
Another Peak Oil Cufuffle Part III
Another Peak Oil Cufuffle Part IV
Another Peak Oil Cufuffle Part V
Another Peak Oil Cufuffle Part VI
Another Peak Oil Cufuffle Part VII
Another Peak Oil Cufuffle Epilogue
4. "All oil field extraction profiles show that an oil field's output, bar a few hiccups around the plateau, rises to a peak, levels out and then falls away. This is empirical fact recorded in thousands of actual, real oil fields around the world."
It is true that the production rate from each individual oil well ever drilled has slowly declined over the years. There is a perfectly valid technical reason for this predictable reduction in flow rate.
When oil is extracted, it flows out through pores in the reservoir rock, and then into an open borehole, from there it is transported to surface by a production tubing string.
Tiny quantities of super fine silt may exit through the pores but do not continue to the surface with the oil, tumbling around in the turbulence instead, until the silt very slowly starts to block off the oil producing pore throats.
Overtime this natural "clogging" process causes the initial production rate of the well to slowly decline.
However, this is certainly not an indication that the oil field itself is becoming depleted, as has been proven thousands of times by offset (multi lateral) wells drilled later into the same reservoir.
You constantly need to keep your pressure high, and usually this is acheived later in a wells life as a secondary method by pumping in seawater or steam.
This means the longer you are pumping out of a particular oil well, the percentage of water you pump back up is going to increase. A consequence of "water cut" is that effective production starts declining after a while.
Yes, you can restore a well to its previous flow rate without the water cut effect, but its expensive, time consuming and the well has to be taken out of production to do so.
You first pull the production tubing out of the hole, and then run back in with a drill string, to which is attached an under reamer.
The under reamer will cut away the contaminated face of the well to a depth that will once again expose pristine producing pores.
As the spinning under reamer is slowly lowered, it enlarges the size of the hole, with the "clogging" debris cut away and flushed back to surface by the drilling fluid.
You now have a "new" oil well flowing at its previous rate. This procedure is rarely followed as 99 times out of 100, its cheaper to drill another offset well in the same reservoir.
Empirical evidence can be deceiving, especially from a bias source such as the petrochemical industry. Remember, there are lies, damm lies and then statistics.
Aside from the P.O. theory being Malthusian in nature, "water cut" and "clogging" are two reasons why the very "flow" data that Hubbert's calculations depend can be flawed.
Meanwhile, the recovery rate from existing world oil fields has increased from about 22% in 1980 to 35% today due to new technology and this trend will continue.
In addition, the ratio between proven oil reserves and current production has constantly improved, passing from 20 years in 1948 to 35 years in 1972 and reaching about 40 years in 2003.
These improvements occurred even with low investment in new exploration and upgrading technology due to the low oil prices during the last 20 years. More to come in Part V.
Another Peak Oil Cufuffle
Another Peak Oil Cufuffle Part II
Another Peak Oil Cufuffle Part III
Another Peak Oil Cufuffle Part IV
Another Peak Oil Cufuffle Part V
Another Peak Oil Cufuffle Part VI
Another Peak Oil Cufuffle Part VII
Another Peak Oil Cufuffle Epilogue
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