B.Tech (Petroleum engineering) 2nd year (2019-2020)
2nd Mid Term Exam: Fundamental of well logging techniques
Date: 03.05.2020 Time: 03.00 p.m. – 04.30 p.m. Maximum Marks: 50
Instruction to Students
1. Mode of Examination shall be conducted in the form of an Online Examination
using the web-service of Moodle only.
2. Duration of Examination shall be 90 minutes for answering the question paper
and an additional 15 minutes shall be given to the student for Uploading of
Answer-sheets written in his/her own readable clear hand-writing, in the pdf format
only. (Timing 3.00PM to 4.30 PM)
3. The answer-sheets uploaded after the specified time duration should be rejected and
not be evaluated by the examiner.
4. This is an Open Book Examination. But the students are not supposed to share
answers with their friends.
5. Attempt ALL Questions. Answers should not be ambiguous.
QUESTION 1.
Why the microannulus is developed between cement and casing? Why the newly developed Ultra
Sonic Imager (USIT) tool is not sensitive to microannulus but the CBL is susceptible to the
presence of microannulus? Is USIT and CBL give the information about the bond quality between
cement and the formation? Explain the principle of CBL-VDL combination tool for giving
information about the bond quality between cement and the formation. Explain why CBL-VDL
tool is always run centralized into the well. (10)
QUESTION 2. Explain how the Induced gamma-ray spectroscopy tool (GST, RST) provides
porosity, salinity, lithology, etc in cased holes. Also, explain how it can provide the current oil
saturation in sick and non-flowing wells. (10)
QUESTION 3. What do you understand from Spinner flowmeter, thermometer, and
gradiomanometer logs? Identify and explain perforated intervals that are contributing to fluid
production from Production log suite (log enclosed). Also, explain why temperature and
gradiomanometer logs are similar in the top and lower portions.
(15)
QUESTION 4. Explain how the formation testers Repeat Formation Tester (RFT) and Modular
Dynamic Tester (MDT) and Selective Formation Tester (SFT) can be used to estimate formation
permeability. Also, explain how it can be used for knowing the fluid contacts. Answer following
also.
1. Identify the fluid contact in given pressure data (Depth verse Pressure Plots enclosed)
2. Draw Dip patterns and Dip azimuth plots against geological Structures (Fold, Fault, and
Unconformity). (15)
