BLOWOUT! (Part 1)
Oil and natural gas are under pressure far inside the earth. It is trapped in geologic formations thousands of feet below ground. When drilling rigs drill down to release the flow of these hydrocarbons to the surface for later production, the drill string punctures these formation zones and releases the trapped gas and/or oil into the borehole.
As the gas/oil flows into the hole created by the drill string, the pressure increases because the hydrocarbons are seeking escape through a relatively miniscule egress created by the drilling pipe.
In the early days, drilling rigs had no method of controlling highly pressurized oil or gas as it shot toward the surface.
When the oil or gas travels upward through the borehole, it gains in speed and increases in pressure. If the formation pressure within the earth is relatively minor, it will be easier to control when it reaches the surface.
But sometimes the drill string (composed of drilling pipe and the bottom hole assembly) punctures a downhole formation under very high natural pressure. The oil or gas within the formation zone thousands of feet below ground then begins flooding into the borehole at a high rate of speed and shoots rapidly toward the surface gaining speed exponentially as it blasts upward. Since oil and gas wells often exceed two or three miles in depth, and some are even deeper, there is time to contain what is known as the kick before it reaches the earth’s surface and the drilling rig.
This is done through the use of BOPs, or Blow-out Preventers. These are a series of large valves below the drilling rig that can be closed off quickly to prevent a blowout in cases of large amounts of rapidly rising oil and/or natural gas. Also, there is much on-site instrumentation designed to detect such hydrocarbons within the wellbore. If everyone is on their game, blowouts can be prevented and contained. The oil/gas can then be slowly and safely bled off and burned off over time and the rig can remain under control. But drilling rigs can squat on a veritable giant powder keg for days and weeks until the well pressure and danger is vented and reduced to a manageable level.
On occasion, though, the pressurized hydrocarbons arrive so quickly at the surface of the wellhead that the entire drilling rig is destroyed and melted to the ground. It is sometimes the case that thousands of feet of drilling pipe flies out of the well hole like spaghetti as if shot from an underground cannon.
And any small spark can ignite the natural gas upon reaching the surface.
[To Be Continued]
© 2013 by RJ Dawson. All Rights Reserved.
 Unless otherwise noted all Scriptures are taken from the New American Standard Bible, © 1960, 1963, 1968, 1971, 1972, 1973, 1975, 1977, 1995 by The Lockman Foundation. Used by permission.
Posted on January 11, 2013, in Current Events and tagged Blowout Preventers, Drilling Rigs, Geologic Formations, Oil and Natural Gas Wells, Pressurized Hydrocarbons, The Lucas Gusher 1901. Bookmark the permalink. Leave a comment.