JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisites

General Geology and Petroleum Geology

Course Objectives:

• To know the logging terminology.
• To delineate hydrocarbons through direct and indirect means/methods.
• Determination of formation lithology through logs like S.P, G.R etc. and also depositional environment with the help of Gamma rays spectroscopy and Dip-meter tools.
• Determination of physical properties of the subsurface, strata like resistivity, porosity, thickness etc. through tools like latero, induction, density, neutron, etc.
• Hydrocarbon saturation estimation with the data acquired by the logging tools.
• Hydrocarbons reserves estimation in a particular block.
• Refinement of the log interpretation data with the help of advanced technology tools namely, Scanner, NMR, Modular formation tester etc.

Course Outcomes

From the well logs:

• Will be able to identify the lithology, depositional environment of subsurface strata.
• Will be able to calculate the porosity, permeability, thickness of different interesting layers in a well.
• Finally, the hydrocarbon saturation in different reservoir rocks can be calculated at the well site itself.

UNIT - I

Direct Methods: Mud logging- coring – conventional and sidewall coring - Core analysis. Concepts of well logging: What is well logging? - Logging terminology-Borehole environment- Borehole temperature and pressure-Log header and depth scale-Major components of well logging unit and logging setup- Classification of well logging methods-Log presentation- Log quality control.

UNIT - II

Open hole logging: SP Logging- Origin of SP, uses of SP log-Calculation of salinity of formation water- Shaliness-Factors influence SP log. Resistivity log: Single point resistance log (SPR)- Conventional resistivity logs- Response of potential and gradient logs over thin and thick conductive and resistive formations-Limitations of conventional resistivity tools. Focused resistivity log- Advantages of focused resistivity tools over conventional resistivity tools. Micro resistivity log: Conventional and focused micro resistivity logs and their application. Induction log: Principle of induction tool and the advantages. Criteria for selection of induction and lateral logging tool. Determination of true resistivity (Rt) of the formation-Resistivity index-Archie’s equation.

UNIT - III

Gamma ray log: principle of radioactivity-Uses of gamma ray log- Determination of shaliness of formation-API counts- Calibration of Gamma ray tool-Statistical fluctuation- Time constant. Natural Spectral Gamma ray log: Principle and application. Caliper log: Principle and application of caliper tool. Density log: Principle of density tool- Environmental Corrections-Porosity Determination-Tool calibration. Litho density log. Neutron log: Principle and application of neutron tool. Porosity determination.

R18 B.TECH PETROLEUM ENGG. III YEAR

Sonic log: Principle and application of sonic log-Bore hole compensation-Determination of primary and secondary porosity, determination of mechanical properties of rock, elastic constants, fractures etc.

UNIT - IV

Cased hole logging: Gamma ray spectral log-Neutron decay time log-Determination of fluid saturation behind casing-Cement bond log- Casing collar log-Depth control- Perforation technique- Free point locater and Plug setting-Casing inspection logs. Production logging: Solving production problems with the help of Fluid Density log- Temperature log and Flow meter logs.

UNIT - V

Advances in Well logging: Dip meter log-Formation tester-Cased hole resistivity logs -Nuclear magnetic resonance log & Scanner logs (Sonic scanner, MR scanner Rt scanner). Outcome: Calculating the dip of the formations, collection of fluid samples from wells for confirmation of log interpretation, and also recording resistivity in cased holes. Interpretation: Quick look interpretation- Cross plots. Neutron- Density, Sonic- Density, Sonic- Neutron cross plots-Hingle plot-Mid plot –Correlation- Hydrocarbon reserve estimate.

TEXT BOOKS:

• 1. Formation evaluation, Edward J. Lynch, Harper & Row, 1962.
• 2. Well logging and formation evaluation, Toby Darling, Elsevier, New York, 2005.
• 3. Well Logging & Reservoir Evaluation, Oberto Serra, Editions Technip, 2007. R18 B.TECH PETROLEUM ENGG. III YEAR