Homework_Assignment_5_Solution

Homework_Assignment_5_Solution - Homework Assignment No. 5...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Homework Assignment No. 5 February 23, 2010 Due on March 2, 2010 @ 2:00 PM PGE368 Spring Semester 2010 Fundamentals of Well Logging Instructor: Carlos T. Verdín, Ph.D. SOLUTION SET DESCRIPTION: The objectives of this homework are: (a) To exercise the conceptual understanding of bulk density and PEF logs, (b) To estimate lithology from bulk density and PEF logs, (b) To calculate porosity from bulk density logs, and (c) To integrate bulk density and PEF logs with resistivity and natural gamma-ray logs for the joint estimation of porosity and water saturation. GUIDELINES FOR THE PREPARATION OF HOMEWORK REPORTS: (a) YOUR REPORT SHOULD BE CLEAN, NEAT, AND WELL ORGANIZED. DESCRIPTIONS SHOULD BE LEGIBLE AND READABLE. (b) THE REPORT SHOULD INCLUDE CLEAR AND COMPLETE TECHNICAL DESCRIPTIONS WHEREVER NECESSARY. (c) ALL FIGURES AND TABLES SHOULD BE LABELED AND PROPERLY ANNOTATED WITH A CAPTION. PLOTS SHOULD BE DISPLAYED WITH THEIR AXES, VARIABLES, AND MEASUREMENT UNITS. (d) ALL RELEVANT RESULTS AND QUANTITIES SHOULD BE WRITTEN WITH THE CORRESPONDING MEASUREMENT UNITS. (e) ATTENTION SHOULD BE PAID TO NUMBER OF DECIMAL FIGURES USED TO DISPLAY RESULTS. (f) SPREADSHEETS ARE NOT SELF-EXPLANATORY NOR ARE LOOSE FIGURES. POINTS WILL BE DEDUCTED FROM HOMEWORK THAT DOES NOT ADHERE TO THE ABOVE PRESENTATION RULES.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
THE FOLLOWING QUESTIONS ARE WORTH 2 POINTS EACH: 1. The density tool measures: (a) Formation bulk density (b) Electron density (c) Apparent formation density 2. The density tool is not sensitive to invasion (a) True (b) False Even though density measurements are shallow sensing, there could be cases of high porosity or low residual hydrocarbon saturation wherein the measurement could be sensing both original fluid as well as mud-filtrate saturation. 3. The density tool alone can differentiate between water and gas saturation (a) True (b) False Bulk density is affected by both matrix density and fluid density. Without an external way (or external information) to separate the effects of matrix and fluid, it is impossible to differentiate fluid and matrix effects on bulk density. 4. Density porosity measures primary as well as secondary porosity (a) True (b) False Porosity is not measured by density porosity. It is calculated from the measured electron density by making specific assumptions about the type of fluid and solid components that make up the rock. The corresponding formulae do not differentiate between primary or secondary porosity but rather emphasize total porosity. 5. PEF is more sensitive than density to presence of barite in the mud (a) True (b) False The PEF of barite is so high (~267 b/e - ) that the recorded PEF will be mostly influenced by barite. 6. In general PEF is sensitive to the rock’s fluid content (a) True (b) False PEF is only slightly sensitive to the rock’s fluid content especially at low values of porosity.
Background image of page 2
THE FOLLOWING QUESTIONS ARE WORTH 3 POINTS EACH: 7. Given the density porosity in water-filled sandstone porosity units measured across a pure shale, what additional information do you need to calculate shale porosity?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/13/2012 for the course PGE 368 taught by Professor Staff during the Spring '08 term at University of Texas at Austin.

Page1 / 25

Homework_Assignment_5_Solution - Homework Assignment No. 5...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online