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Petroleum geology lab 1
- 2. By teacher Mr. KarwanYousif Presentation About University of Zakho College Of Engineering Department Of Petroleum Engineering Petroleum Geology Supervisor Mr. Nizar Botani
- 4. Rocks are acombination of minerals that are bonded together in some way. • All rocks are made of minerals • Monomineralic- contain one mineral • Polymineralic- contain more than one mineral Rocks are classified into three groups by how they are formed Types of Rocks Igneous Sedimentary Metamorphic
- 5. 3 types ofRocks Types of Rocks Igneous Sedimentary Metamorphic Igneous Rocks: Form from molten rock that cools and hardens. •Sedimentary Rocks: Form from sediments (pieces of other rocks) that are cemented together. •Metamorphic Rocks: are formed when old rocks change by heat and pressure. Rocks are classified by how they form
- 6. Classification of igneousrocks-2 types Intrusive • Form from magma • Cooled and solidified (hardened) slowly deep underground • Large crystal size Extrusive • Form from lava • Cooled and hardened quickly at or near the surface of the earth. • Small or no crystals
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- 8. Can be: • Felsic:light colored rocks that are rich in elements such as aluminum, silicon. Lower density • Mafic: dark colored rocks that are rich in iron and Mg. Higher density • Coarse-grained texture: takes longer to cool, larger visible mineral crystals • Fine-grained texture: cools quickly with small mineral crystals • Glassy Texture: cools the quickest, no mineral crystals form • Vesicular texture: Gas pockets (holes) • (note) Texture refers to the size/appearance of the minerals
- 10. Metamorphic Rocks • Metamorphicrocks are formed by the effect of heat and pressure on existing rocks. • This can greatly affect the hardness, texture or layer patterns of the rocks. Magma metamorphic rock forming here heat Pressure from surface rocks
- 11. Types of Metamorphicrock There are two basic types of metamorphic rocks. • Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure. • Non-foliated metamorphic rocks such as hornfels, marble, quartzite do not have a layered or banded appearance.
- 12. Metamorphic Rock • Determineif the following rock samples are foliated or non-foliated: Amphibolite Quartzite Phyllite Foliated
- 13. THE ROCK CYCLE •One of the cycles of nature that continually recycles rocks & materials that make up Earth’s crust siltstone slate gneiss limestone marble shale
- 14. Metamorphic Rocks • ContactMetamorphism – heated by nearby magma • Increased temperature changes the composition of the rock, minerals are changed into new minerals
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- 18. Fragments of rockget broken down into sediments Sediments are transported, compacted, and cemented into rock 1. Are usually formed in a watery environment. 2. Often layered 3. Are the only rocks that contain fossils
- 19. Sedimentary Rocks Sedimentaryrock is formed by erosion Sediments are moved from one place to another Sediments are deposited in layers, with the older ones on the bottom The layers become compacted and cemented together
- 20. Sedimentary Rock SedimentaryRocks are formed at or near the Earth’s surface No heat and pressure involved Strata – layers of rock Stratification – the process in which sedimentary rocks are arranged in layers
- 21. Sediment • Sediment -loose, solid particles originating from: – Weathering and erosion of pre-existing rocks – Chemical precipitation from solution, including secretion by organisms in water • Classified by particle size – Boulder - >256 mm – Cobble - 64 to 256 mm – Pebble - 2 to 64 mm – Sand - 1/16 to 2 mm – Silt - 1/256 to 1/16 mm – Clay - <1/256 mm Gravel
- 22. From Sediment toSedimentary Rock • Transportation – Movement of sediment away from its source, typically by water, wind, or ice – Rounding of particles occurs due to abrasion during transport – Sorting occurs as sediment is separated according to grain size by transport agents, especially running water – Sediment size decreases with increased transport distance
- 23. • Deposition – Settlingand coming to rest of transported material – Accumulation of chemical or organic sediments, typically in water – Environment of deposition is the location in which deposition occurs • Deep sea floor • Beach • Desert dunes • River channel • Lake bottom From Sediment to Sedimentary Rock
- 24. • Preservation – Sedimentmust be preserved, as by burial with additional sediments, in order to become a sedimentary rock • Lithification – General term for processes converting loose sediment into sedimentary rock – Combination of compaction and cementation From Sediment to Sedimentary Rock
- 25. Types of SedimentaryRocks • Detrital (clastic) sedimentary rocks – Most common sedimentary rock type – Form from cemented sediment grains that come from pre-existing rocks • Chemical sedimentary rocks – Have crystalline textures – Form by precipitation of minerals from solution • Organic sedimentary rocks – Accumulate from remains of organisms
- 26. Sedimentary Rock Clastic –made of fragments of rock cemented together with calcite or quartz Breccia is a term most often used for clastic sedimentary rocks that are composed of large angular fragments (over two millimeters in diameter).
- 27. Clastic Sedimentary Rocks •Breccia and Conglomerate – Coarse-grained clastic sedimentary rocks – Sedimentary breccia composed of coarse, angular rock fragments cemented together – Conglomerate composed of rounded gravel cemented together • Sandstone – Medium-grained clastic sedimentary rock – Types determined by composition • Quartz sandstone - >90% quartz grains • Arkose - mostly feldspar and quartz grains • Graywacke - sand grains surrounded by dark, fine- grained matrix, often clay-rich
- 28. Clastic Sedimentary Rocks •Shale – Fine-grained clastic sedimentary rock – Splits into thin layers (fissile) – Silt- and clay-sized grains – Sediment deposited in lake bottoms, river deltas, floodplains, and on deep ocean floor • Siltstone – Slightly coarser-grained than shales – Lacks fissility • Claystone – Predominantly clay-sized grains; non-fissile • Mudstone – Silt- and clay-sized grains; massive/blocky
- 29. Chemical Sedimentary Rocks •Carbonates – Contain CO3 as part of their chemical composition – Limestone is composed mainly of calcite • Most are biochemical, but can be inorganic • Often contain easily recognizable fossils • Chemical alteration of limestone in Mg-rich water solutions can produce dolomite • Chert – Hard, compact, fine-grained, formed almost entirely of silica – Can occur as layers or as lumpy nodules within other sedimentary rocks, especially limestones • Evaporites – Form from evaporating saline waters (lake, ocean) – Common examples are rock gypsum, rock salt
- 30. Sedimentary Rock Chemical sedimentary– minerals crystallize out of solution to become rock Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters.
- 31. Organics in SedimentaryRocks • Coal – Sedimentary rock forming from compaction of partially decayed plant material – Organic material deposited in water with low oxygen content (i.e., stagnant) • Oil and natural gas – Originate from organic matter in marine sediment – Subsurface “cooking” can change organic solids to oil and natural gas – Can accumulate in porous overlying rocks
- 32. Sedimentary Rock Organic sedimentary– remains of plants and animals Coal is an organic sedimentary rock that forms from the accumulation and preservation of plant materials, usually in a swamp environment.
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- 35. The Source Rock Atype of rock which contains organic matter and is capable to generate the hydrocarbons. Best example of source rock is shale. Limestone & Dolomite
- 36. Reservoir Rock • Areservoir rock is that kind of rock which can hold the hydrocarbons. • Most common examples of reservoir rocks are sandstone and Carbonates (limestone and dolomite).
- 37. The Seal orCap Rock • The seal or cap rock is an impermeable rock which don’t allow the hydrocarbons to escape from the reservoir rock. • Common examples of cap rocks are, chalks , shales, clays etc.