ge-ol-o-gy  1. A science that deals with the history of the earth and its life, especially as recorded in rocks.

Oil On My Shoes will help you understand the science of Petroleum Geology
(Using geology to find oil and gas in the earth).

Discover rocks, fossils, drilling for oil and gas, and more!
Learn about sandstone, how to find oil, and the exciting world of Petroleum Earth Science!

 

 

**Beginner** Topics
Five Steps to Drilling and Producing a Well
The Five Main Steps the Petroleum Geologist goes through in order to drill and produce a well.

Sedimentary Rocks
As sediments pile up, the oldest ones are buried deeper and deeper.  When they are buried deep enough, heat and pressure and other workings of the earth make the soft sediments hard, and turn them into rock.
Sandstones and Similar Rocks

Sandstones are composed of fine to coarse sand grains which are cemented together.  Learn about different types of sandstones and how to identify them.

The Geologic Time Scale

By modern scientific calculations, the earth is many hundreds of millions years old.   Decay rates of certain radioactive materials are established and measured, and used as "clocks" to calculate the ages of various rocks. 

Drill_Bit.gif (40481 bytes)Drill Bits and Rock Samples

While a well is drilling, the rock "chips" cut off by the drill bit are pumped to the surface in the drilling mud.  Learn about drill bits, too.

 

Coring a Well

Sometimes, the PG will want to get a better look at the rocks deep in a well than they can get by looking at the small chips called well samples.  In this case, the PG will order that a "core" be taken from the well.  A core is a solid cylinder of rock about 3-4 inches in diameter, and it can be anywhere from a few feet to over a hundred feet long. 

 
Oil and Gas Under Great Pressure
Oil and gas exist in underground traps under great pressure.  When the formation containing the oil or gas is penetrated by the drill bit, the oil and gas can blast out of the well with tremendous force.

Cuttings_In_Hand_2.gif (31498 bytes)Sedimentary Rock Chart

This will help you identify the various types of sedimentary rocks.

**Intermediate** Topics

Porosity and Permeability in Sedimentary Rocks
Porosity of a rock is the ability of a rock to hold a fluid.  Permeability is a measure of the amount of flow of a fluid through a rock. A rock may be very porous, but if the pores are not connected, it will not have any permeability.

 

The Mud Log

While a well is drilling, the rock "chips" cut off by the drill bit are pumped to the surface in the drilling mud.  This section explains what data is gathered from drill cuttings, and shows the construction of a "mud log".

Oil and Gas Traps

You may have heard that oil is found underground in "pools", or "lakes", or "rivers".  Maybe someone told you there was a "sea" or "ocean" of oil underground.  This is all completely wrong!  Check out the right stuff here.

snail1.gif (4391 bytes)Correlating Rocks With Microfossils

Sometimes, in certain areas, the well samples from a drilling well do not indicate  well-defined beds of shale, limestone and sandstone.  In this case, the petroleum geologist may use microfossils to figure things out.

 
Stratigraphic_Cross-Section.gif (11336 bytes)Stratigraphic Cross-Sections
These differ from structural cross-sections in that underground structure or elevation is ignored in the stratigraphic type.   They are "flattened" on a certain formation.  "Strat" cross-sections allow the PG to see see some things more clearly.
Completing a Well
To complete a well so that oil and gas can be recovered, steel pipe is run all the way to the bottom of the hole.  Then an explosive device called a "perforating gun" is used to blast holes right through the heavy steel pipe.

**Advanced** Topics

The Interactive Scout Ticket

The "scout ticket" is a paper or computer file that summarizes all the information available on a single well.  Basic information like the well name, location, depth, and date completed will be found here, as well as a record of the major formation tops encountered in the well, what "treatments", if any were used, and how much oil or gas the well produced initially.

Locating a Well Using the Township and Range System

The Township and Range system is a neat way of locating oil and gas wells in much of the western United States.

 
Structural_Cross_Section.gif (14243 bytes)Structural Cross-Sections
Once the petroleum geologist has electric logs from two or more wells, he usually will make a "Cross-Section".  With a "structural" (struk-sure-all) cross-section, he will show the various positions of the rock formations in several wells.

Geologic Maps

Geologists draw dozens of types of geologic maps.  They want to show the earth as it is deep underground.

 
How To Contour A Map
Learn how a petroleum geologist goes about making a very simple contour map.
Electric Logs
After a well is drilled, "electric logging tools" are run into the hole.  These highly-complex devices produce a long piece of paper called an "electric log".  PG's get much valuable information from electric logs, including rock type, porosity, relative permeability, and the presence of oil, water, or gas.  Electric logs are the most useful tool available to the Petroleum Geologist.

Seismic, 2D and 3D
There are ways to see into the earth without actually having to drill wells!  Seismic can show some amazing things from deep down there!

Using Computers To Keep Track of Stuff
The Petroleum Geologist must keep track of lots of information.  Computers are extensively used to help out.
Oil On MY Shoes GeoShop
Cool Geology Stuff !

This site is dedicated to Mr. J. Howard Berry
Educator, Scientist and Former Principal of Oak Terrace
Elementary School
Now known as J. Howard Berry Elementary School
North Charleston, South Carolina 29406

 

 

 

The Petroleum Geologist will answer questions!  

Email geologistDELETE@geomore.com  Remove the "DELETE" when sending mail; this helps cut down on the junk mail we receive.  Thanks!!

 

Copyright © 1996-2007 by D. Smith.  All rights reserved.  

This site is protected by international copyright.  Do not copy or reproduce materials from this site.


Revised: 19 Jun 2007 16:12:22 -0700 .

This site  is maintained as a public and educational service.  Thank you for visiting.  The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this material, the author assumes no responsibility for omissions or errors.

R06192007:2200

 

 

 

 

 

 
 

 

Copyright © 1996-2007 by D. Smith.  All rights reserved.  

This site is protected by copyright.  Do not copy materials from this site.


Revised: 19 Jun 2007 16:12:22 -0700 .

This site is maintained as a public and educational service.  Thank you for visiting.  The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this material, the author assumes no responsibility for omissions or errors.

R06192007:2200