Thank you, Doctor. Your explanation was excellent and extremely helpful. I have one question: Could you please clarify why sonic logs are generally not effective at detecting secondary porosity? Is the issue related to the complexity of porous media in secondary porosity? Despite the presence of fluid in secondary porosity, which should affect the sonic waves, why is this type of porosity not typically captured by sonic logging?
You are right. First, estimating porosity from sonic log is not straightforward. The equations such as Wylie's time average equations, are empirical and don't work for all rocks. Second, factors such as fluid type (e.g., oil and gas saturation) and presence of clay will affect sonic velocity and if they are not taken into account, we will end up wrong estimate of the porosity. Dipole logs are better for fracture characterization.
I am currently doing my training phase and preparing for wireline field engineer academy at baker hughes and your lectures arr helping me understand what our tools do and how to interpret the logs. Thank you ao much. I hope you continue posting. I am sharing your lectures with my colleagues.
Excuse me sir one thing that I am still wondering about x that sonic log uses what is it exactly is it between receiver or between receivers and formation and if it is between the receivers what if the sound by formation does not come exactly between the receivers
Design of each sonic log is different. Modern sonic logs may use more receivers. The one that I explained is a simple one where the configuration of sources and receivers is symmetrical. So, it is exactly between them.
Best explaination of Sonic log ❤️ I have ever heard and understand completely in a single go.....
Thank you, Doctor. Your explanation was excellent and extremely helpful. I have one question: Could you please clarify why sonic logs are generally not effective at detecting secondary porosity? Is the issue related to the complexity of porous media in secondary porosity? Despite the presence of fluid in secondary porosity, which should affect the sonic waves, why is this type of porosity not typically captured by sonic logging?
You are right. First, estimating porosity from sonic log is not straightforward. The equations such as Wylie's time average equations, are empirical and don't work for all rocks. Second, factors such as fluid type (e.g., oil and gas saturation) and presence of clay will affect sonic velocity and if they are not taken into account, we will end up wrong estimate of the porosity. Dipole logs are better for fracture characterization.
I am currently doing my training phase and preparing for wireline field engineer academy at baker hughes and your lectures arr helping me understand what our tools do and how to interpret the logs. Thank you ao much. I hope you continue posting. I am sharing your lectures with my colleagues.
You are welcome!
Excuse me sir one thing that I am still wondering about x that sonic log uses what is it exactly is it between receiver or between receivers and formation and if it is between the receivers what if the sound by formation does not come exactly between the receivers
Design of each sonic log is different. Modern sonic logs may use more receivers. The one that I explained is a simple one where the configuration of sources and receivers is symmetrical. So, it is exactly between them.
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