Wyllie time-average equation vs Gardner's equation vs RHG Equation for porosity

In summary, the Wyllie time-average equation, Gardner's equation, and the RHG equation are all methods used to estimate porosity in geological formations. The Wyllie equation utilizes the time it takes for seismic waves to travel through different materials, providing a time-weighted average of the properties. Gardner's equation is a more empirical approach that relates density and porosity based on observed data, often yielding simpler calculations. The RHG equation combines aspects of both, offering a more refined estimate by incorporating rock physics principles. Each equation has its strengths and applicability depending on the specific geological context and available data.
  • #1
getsrawal
3
1
TL;DR Summary
Wyllie time-average equation vs Gardner's equation vs RHG Equation and what these equation are different from any other approach for calculating imbition method, ideal gas laws or mercury displacement method
If you were estimating porosity from velocity, which approach would you prefer to use among Wyllie time-average equation, Gardner's equation Or RHG Equation, when and why?

My answer is RHG equation as wylllie equation don't work for unconsolidate sand and give accurate results when it is saturated with brine solution. Garnder's equation mainly relates density with porosity not accounting with velocity and RHG equation is improved one. CAn you please help me with anything i'm missing here.

Are these three equation are different from any other approach like imbition method, ideal gas laws or mercury displacement method for calculating porosity?
 
Earth sciences news on Phys.org
  • #2
Welcome to PF.

Would I be right in guessing that this question is about seismic velocity, in porous rocks, that are water saturated ?
 
  • Like
Likes berkeman
  • #3
Baluncore said:
Welcome to PF.

Would I be right in guessing that this question is about seismic velocity, in porous rocks, that are water saturated ?
yes it is about comparing results given by three equations. It is to discuss mainley what RPG equation have advantages over wyllie and Gardner's equation and what is appropriate method among three to measure porosity from velocity in different types of rocks.
 
  • #4
I am interested in the subject, but it is more than 40 years since I shot my last seismic survey.
Can you please post links to the equations.
 

FAQ: Wyllie time-average equation vs Gardner's equation vs RHG Equation for porosity

1. What is the Wyllie time-average equation and how is it used in porosity estimation?

The Wyllie time-average equation is a method used to estimate the porosity of a rock formation by averaging the travel times of seismic waves through different materials. It is based on the concept that the effective velocity of seismic waves is influenced by the proportions of the rock and fluid phases present. The equation combines the travel times of the wave in the solid and fluid phases to provide an average travel time, which can be used to infer porosity.

2. How does Gardner's equation differ from the Wyllie time-average equation?

Gardner's equation is primarily an empirical relationship that correlates density and sonic velocity in geological materials, specifically for estimating the porosity of rocks. While the Wyllie time-average equation focuses on travel times, Gardner's equation provides a direct relationship between density and velocity, allowing for quick estimates of porosity based on measurable parameters. Gardner's equation is often used in conjunction with other data to refine porosity estimates.

3. What is the RHG equation, and in what context is it applied?

The RHG equation, named after its developers, is another empirical relationship used in geophysics to estimate porosity, particularly in shaly formations. It incorporates the effects of both the shale content and the fluid saturations in the rock. The RHG equation is particularly useful in environments where the presence of shale significantly influences the acoustic properties of the rock, making it a valuable tool for geologists and reservoir engineers.

4. Which equation is most accurate for porosity estimation in different geological settings?

The accuracy of each equation can vary significantly depending on the geological setting and the specific characteristics of the rock formation. The Wyllie time-average equation is generally effective in clean, homogeneous formations, while Gardner's equation may provide more accurate results in consolidated rocks. The RHG equation excels in shaly environments where the influence of shale content is critical. It is essential to select the equation based on the specific conditions and available data for the best results.

5. Can these equations be used interchangeably, or do they have distinct applications?

While all three equations aim to estimate porosity, they have distinct applications and should not be used interchangeably. Each equation is formulated based on different assumptions and empirical data, making them suitable for specific types of geological formations. It is crucial to understand the context and limitations of each equation to select the most appropriate one for a given geological scenario.

Similar threads

Find an equation for position vs time given potential vs position?
Replies
1
Views
2K
Average Velocity vs Average Velocity discrepencies?
Replies
4
Views
2K
Representing instantaneous velocity vs time on a graph
Replies
1
Views
3K
I Progress In Calculating The HLbL Contribution To Muon g-2
Replies
0
Views
129
Time and Indeterminacy vs. Continuity
Replies
14
Views
5K
Einstein did not derive E =mc2 first
2
Replies
38
Views
44K
A review of dowsing: Evidence for and against
Replies
11
Views
26K

Hot Threads

Recent Insights

Back
Top