Introduction to well logs for use in the petroleum industry
This activity was selected for the On the Cutting Edge Exemplary Teaching Collection
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- Scientific Accuracy
- Alignment of Learning Goals, Activities, and Assessments
- Pedagogic Effectiveness
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This page first made public: Jun 5, 2014
- instructs students to recognize mudstone vs. sandstone lithology using spontaneous potential and gamma ray logs.
- Teaches the concepts of resistivity and conductivity and their underlying causes in pore fluids.
- Shows how to recognize briny pore fluids and hydrocarbons using resistivity logs.
- Instructs how the sonic log can be used to recognize zones of high and low porosity.
- Contrasts high resistivity zones occurring due to cementation versus those with resident hydrocarbons.
- Uses density and neutron logs to recognize gaseous hydrocarbons in the subsurface.
Skills and concepts that students must have mastered
I intend to use the exercise as a culminating session that brings together several concepts in a professional context tilted toward the petroleum industry and as an introduction to well logs. Students in sedimentology/stratigraphy should first master sedimentary lithologies and the concept of porosity and permeability.
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
- Analysis of data, in particular using a suite of electric logs to arrive at an interpretation of lithology and fluid content.
- Hypothesis formation and testing.
Other skills goals for this activity
Description and Teaching Materials
The exercise uses 5 logs focusing mainly upon 2 different portions of the stratigraphic section – one in which potential reservoir rock (unconsolidated sand) contains brine and one in which reservoir rock contains gaseous hydrocarbons (natural gas or methane). Spontaneous potential and gamma ray logs are used to differentiate between mudstone (or shale) and non-shale (unconsolidated sand) lithologies. Resistivity logs are used to recognize pore fluids – again brine and hydrocarbons. Sonic logs are used to show that cementation within sands can lead to high resistivity, which can be misinterpreted as hydrocarbons. Lastly, density and neutron logs are used to recognize gaseous hydrocarbons due to crossover.
Student handout for Introduction to well logs (Microsoft Word 134kB Jun4 14)
Answers to exercise questions (Microsoft Word 142kB Jun4 14)
Well logs for exercise, Introduction to Well Logs (Microsoft Word 2007 (.docx) 35.9MB Jun4 14)