SAFOD will give researchers a unique window into the process of strain build-up and release in the fault zone during numerous "microearthquakes. While these microearthquakes usually aren't felt at the surface, they offer important clues about the origin of bigger, more destructive quakes. Geological Survey, said the San Andreas fault is creeping at a rate of about 1 inch per year near the drill site.
Most earthquakes occur in a zone no more than 10 yards wide. This is the first time "we've been inside the earthquake machine," said Ellsworth. We've studied them from afar, but we've never before been where the action is. Scientists now will be able to recreate the earthquake process in the laboratory using real materials and under real conditions that exist deep within the San Andreas Fault.
In addition to retrieving fault zone rocks and fluids for laboratory analyses, intensive down-hole geophysical measurements and long-term monitoring will take place within and adjacent to the active fault zone. Evaluating the roles of fluid pressure, rock friction, chemical reactions, stress and other parameters contributing to the earthquake process will allow scientists to simulate earthquakes in the laboratory using representative fault zone properties and physical conditions, said van der Vink.
EarthScope is one of the National Science Foundation's largest undertakings. Credit and Larger Version. Drilling provides a research window into the San Andreas Fault. My guess would be the amount of energy man can put into the system is negligible compared to the forces put in play by the plates moving around. Anyway as a more factual answer as to what happens when an oil well is drilled though a fault I offer the following.
Well first off, I should explain that when a well is drilled, a drilling fluid is pumped down through the drill pipe, out the bit and back up the annular space between the hole and the drill pipe the drill bit has a larger diameter then the pipe behind it. This fluid has several purposes, amongst which, it provides cooling for the bit, it transports all the cut up rock back to surface, and most importantly it provides a pressure balance against the formation pressure.
As one drills deeper the hydrostatic pressure due to the column of fluid increases just in the same way as the water pressure increases the deeper one goes in the ocean , this increase offsets the increasing pressure the rock is under.
The drilling fluid density, hence the pressure it exerts, can be adjusted by adding powdered barite, using salt saturated solutions, using weird cesium formate solutions, using synthetic oil based fluids and other magic snake oils. One thing they all have in common is they are not cheap. Honest I do remember the question, which leads lesson to faults. A fault represents a break in the geological sequence of rocks. As you pass across a fault you may not always cross from one formation type which was deposited under certain conditions, to another.
This sudden change of stability and pressure may not be correctly balanced by the drilling fluid pressure, this imbalance may lead to several unpleased things happening. So drilling through a fault can have some untoward effects in the drilling process,. The actual zone of the fault may have a fair amount of broken rubble which could cave into the bore hole, worst case it may lead to the drill string getting stuck in the hole, which is expensive.
You could loose circulation, basically the fault can be a fissure into which all the drilling fluid can drain. The loss of drilling fluid, whilst representing a cost, may also lead to a decrease in the pressure further up the hole as hydrostatic head is lost. The drop in well bore pressure may not correctly balance the formation pressures and so a kick may be induced, or well bore collapse. You enter into a new formation with a higher formation pressure. The drilling fluid pressure and the formation pressure are out of balance and the well bore may collapse, or if there are permeable and porous formations, formation fluids may be forced into the well bore resulting in a kick and a blowout.
A fault may also be a conduction path from deeper formations to shallower formations. Some of the researchers are keen to know whether or not the faults favor certain microbes. They will place equipment that is triggered by seismic activity into the fault in order to find out. The theory is that when the lines rupture, they release a pulse of hydrogen, which bacteria thrive on.
The work will also help the mine operators. In such a seismically active region, the companies are obviously concerned about triggering more quakes, which have previously caused fatalities. This research, therefore, may provide insight into how human activity can trigger earthquakes.
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