lecture 01_wellsite geology_part 1

PAB 2084/PCB 2044 Well Logging & Formation Evaluation Lecture 1 Wellsite GeologyMD HABIBUR RAHMAN/GEOSCIENCES/UTP

By: Md Habibur Rahman Lecturer Department of Geosciences Universiti Teknologi PETRONAS [email protected] Office 19-03-14, Extn: 71141

Assessment Criteria Coursework

(Tests, Assignments and Quizes) Final ExamMD HABIBUR RAHMAN/GEOSCIENCES/UTP

50%

50%

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References1. Bassiouni, Z. (1994), Theory measurement, and

interpretation of well logs, SPE Textbook Series Vol. 4.2. Hill, A. D. (1990), Production logging- Theoretical and

interpretive elements, SPE Monograph Series, Vol 14.MD HABIBUR RAHMAN/GEOSCIENCES/UTP

3. Raider, M. (1996), The geological interpretation of well

logs 2nd edition, Whittles Publishing.4. Materials provided during the course lecture3

Md Habibur Rahman: short bio I received B.Sc. (Hons.) in Geology (2003-2006 session), U. of Dhaka, Bangladesh. I received a M.Sc. by research in Petroleum Geosciences from UTP in 2011. Visiting scholar to University of Leuven, Belgium in 2010 I joined UTP in 2011 as a lecturer in Geosciences Department.MD HABIBUR RAHMAN/GEOSCIENCES/UTP

I am a full time researcher in the carbonate research center (SEACARL) at UTP, where we work with PETRONAS and SSB. I currently supervise few FYP and ETP projects.4

Drilling and sampling a wellTwo kinds of data are obtained during drilling: -those linked to rock samples (full diameter cores or sidewall cores, cutting), and to fluid sample; - those provided by physical measurements made in drilled holes essentially by wireline logging tools. Standard cores, if they are continuous, constitute a sampling of good quality that will give abundant data.

MD HABIBUR RAHMAN/GEOSCIENCES/UTP

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1- Cuttings chips To facilitate a thorough examination of cuttings samples for their lithology, composition, and for the presence of microflora and microfauna, the drilling mud must be washed from the cuttings to provide a clean sample.

Cuttings analysis may include relative proportions of rock types, biostratigraphy, and mineralogy (Fig. A1).


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Direct Methods Drill CuttingsMud logging.. l. Examination and analysis of geological information from formation cuttings and drilling mud to determine if oil and gas are encountered during drilling a well 2. Washed sample description onsite, dried & packed for petrography 3. Unwashed sample paleontology, geochemistry


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PetrographyPetrology (from the Greek petra, "rock" and logos, "study") is the branch of geology that studies the origin, composition, distribution and structure of rocks

Petrography is a branch of petrology that focuses on detailed descriptions of rocks.


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Method of Investigation in Petrography1. Macroscopic Observation Physical properties of rocks and minerals in hand specimen (e.g. Structure, texture, hardness, compaction etc.)

1. Microscopic Observation Optical properties of minerals mostly in thin section (e.g. Microfacies, composition, mineral identification etc.1. Geochemical Analysis Rocks composition in terms of elements; key to the advanced petrography


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Macroscopic Observation1. Cuttings 2. Core Analysis


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Microscopic Observation1. Petrographic microscopy a) Transmitted light b) Reflected light

2. Fluorescence microscopyMD HABIBUR RAHMAN/GEOSCIENCES/UTP

3. Cathodoluminescence microscopy 4. Scanning electron microscopy11

Transmitted light microscopy

Scanning electron microscopy

Microscopic Observation

Preparation of impreg. thin section

Fluorescence miroscopy


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Geochemical Analysis1. X-ray Diffraction (XRD) Composition of rock 2. Neutron Magnetic Resonance (NMR) Pore connectivity, pore size distribution in rocks 3. Stable isotope analysis Oil-oil and oil-source rock correlation, Gas characterisation and reservoir compartmentation 4. Gas Chromatography Oil and extract characterisation 5. High Temperature Gas Chromatography Wax characterisation C14 to C80+ 6. Pyrolysis Oil to gas generation potential 7. Vitrinite Reflectance Sediment maturity profile


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Geochemical Analysis

XRD spectrum for Kinta Valley limestone Sampling for stable isotope analysisMD HABIBUR RAHMAN/GEOSCIENCES/UTP

XRD spectrum for Kinta Valley limestone

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Paleontology


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Geologic Timescale


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Fig. A2. (A) Basic parts of a drilling rig, including the derrick, the turntable that turns the drill string, and the bit that rotates and cuts through the rock. (B) Whole core that is boxed and ready to be shipped to a core analysis facility after being washed. (C) Slabbed core that has been cut lengthwise in two, with the side shown having been polished. (D) Close-up of a core piece from which a core plug has been obtained for porosity and permeability measurement. These plugs are obtained while the core is still whole (B).17

Wellsite Mud loggingDuring the drilling of a well there will typically be a mudlogging unit on the rig. This unit has two main responsibilities: 1. To monitor the drilling parameters and gas/liquids/solids returns from the well to assist the drilling department in the safety and optimization of the drilling process 2. To provide information to the engineering unit that can be used for evaluation purposes


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Fig. A1. Example showing different types of sandstones (friable and cemented; shades of yellow/white and green/bright-gray), mudstone (gray/dark-gray), and shale (black) that were determined from cuttings and whose proportions were counted through 3 m (10 ft) intervals. The cuttings log shows the proportions of each rock type throughout the entire 500-ft interval in this well. Various well logs are shown to the right. 19

Core Cores analysis may include relative proportions of rock types, sedimentary structures, and colour. The core, for analysis of porosity, permeability, and a measure of fluid saturation. One slab is used for sampling, and the surface of the other slab is ground to a smooth finish and is used for detailed geologic description and photographing (Fig A2).


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Core logging


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lecture 01_wellsite geology_part 1

Documents

md habibur

include relative

thin section

drilling mud

xrd spectrum

rock types

proportions

analysis