This document provides an overview of petroleum geology, including:
1. It defines petroleum geology as the study of the origin, generation, migration, and accumulation of hydrocarbons, with the goal of exploring for and producing oil and gas.
2. Petroleum can occur as liquid (crude oil), gas (natural gas), or solid/semi-solid forms like asphalt or bitumen. Natural gas exists as either associated or non-associated gas.
3. Crude oils vary in properties like specific gravity, viscosity, pour point, and optical activity. The origin of petroleum is now widely accepted to be organic rather than inorganic.
This document provides a basic overview of the fundamental rock properties. It delivers a detailed analysis of the basic reservoir rock properties like porosity, permeability, Fluid saturation , wettability, etc.
Porosity and permeability are key properties that determine whether rock can effectively store and transmit hydrocarbons. Porosity refers to void space that can hold fluids, while permeability refers to how easily fluids can flow through interconnected pore spaces. There are different types of porosity and permeability based on pore connectivity and origin. Important reservoir rocks include clastic rocks like sandstone and carbonate rocks, which have sufficient original or secondary porosity. Hydrocarbons generated in source rocks can migrate through reservoir rocks, becoming trapped in structural or stratigraphic traps created by geological processes like folding or variations in rock layers.
This document provides an overview of petroleum geology, including:
1) It discusses the key components of petroleum geology - geochemistry, geophysics, and biology.
2) It explains the process of formation of an oil accumulation, which requires a source rock, reservoir rock, seal, and trap.
3) It describes the basic components of organic matter in sediments and how they are transformed into kerogen and then oil and gas through burial and heating over time.
Petroleum geology relates to the origin, migration, and accumulation of oil and gas. Key points in the document include:
- Early discoveries were near oil seeps at the surface. The anticline theory proposed that oil would accumulate in structural folds.
- Subsurface geology studies helped trace lateral changes in rock layers. Geophysics tools like seismography and gravity measurements aided exploration.
- Modern methods include direct hydrocarbon detection, which identifies gas reservoirs as bright spots on seismic data, and seismic stratigraphy for tracing facies.
1. The document describes the key elements of a petroleum system including the source rock, migration route, reservoir rock, seal rock, and trap that are necessary for oil and gas accumulation.
2. It explains the processes of generation of petroleum from organic-rich source rocks buried deep underground and subjected to heat and pressure over millions of years, and the migration of oil and gas from the source rock into porous reservoir rocks.
3. The document outlines the characteristics of reservoir rocks that allow for the accumulation and storage of oil and gas, as well as cap rocks that form an impermeable seal above reservoir rocks preventing further migration and trapping hydrocarbons below.
Petroleum geology is the application of geology to explore for and produce oil and gas. It relies on understanding rock structures that can trap hydrocarbons underground. Key techniques used include seismic surveys, which use shock waves to map underground rock layers and structures that may indicate oil and gas traps. Important milestones include the development of the anticlinal theory of trapping in 1883, the invention of the seismograph in 1914, and the introduction of 3D seismic in the 1980s to improve imaging of underground structures.
This document discusses secondary migration of petroleum, which is the movement of oil and gas within reservoir rocks after primary migration. The main forces driving secondary migration are buoyancy, as oil and gas are less dense than water, and hydrodynamic forces from water flow. Capillary pressure acts as a resistant force. Secondary migration can occur over distances ranging from hundreds of meters to over 100 km and is facilitated by porous and permeable pathways as well as pressure gradients within the rocks. Water drive and gas flushing are two mechanisms enabling secondary migration to traps and accumulations. Fractures also provide routes for secondary oil and gas to migrate through reservoir strata.
Source rocks are sedimentary rocks that contain significant amounts of organic matter. When buried and heated to sufficient temperatures, this organic matter will generate oil or gas. Effective source rocks contain at least 0.5% total organic carbon and have generated hydrocarbons that have formed commercial oil and gas accumulations. The key characteristics of a source rock are that it contains sufficient quantities and quality of organic matter and reaches the appropriate levels of thermal maturity to generate hydrocarbons. For a source rock to form, conditions must allow for high biological productivity, anoxic conditions to preserve organic matter, and rapid burial of organic-rich sediments.
This document provides a basic overview of the fundamental rock properties. It delivers a detailed analysis of the basic reservoir rock properties like porosity, permeability, Fluid saturation , wettability, etc.
Porosity and permeability are key properties that determine whether rock can effectively store and transmit hydrocarbons. Porosity refers to void space that can hold fluids, while permeability refers to how easily fluids can flow through interconnected pore spaces. There are different types of porosity and permeability based on pore connectivity and origin. Important reservoir rocks include clastic rocks like sandstone and carbonate rocks, which have sufficient original or secondary porosity. Hydrocarbons generated in source rocks can migrate through reservoir rocks, becoming trapped in structural or stratigraphic traps created by geological processes like folding or variations in rock layers.
This document provides an overview of petroleum geology, including:
1) It discusses the key components of petroleum geology - geochemistry, geophysics, and biology.
2) It explains the process of formation of an oil accumulation, which requires a source rock, reservoir rock, seal, and trap.
3) It describes the basic components of organic matter in sediments and how they are transformed into kerogen and then oil and gas through burial and heating over time.
Petroleum geology relates to the origin, migration, and accumulation of oil and gas. Key points in the document include:
- Early discoveries were near oil seeps at the surface. The anticline theory proposed that oil would accumulate in structural folds.
- Subsurface geology studies helped trace lateral changes in rock layers. Geophysics tools like seismography and gravity measurements aided exploration.
- Modern methods include direct hydrocarbon detection, which identifies gas reservoirs as bright spots on seismic data, and seismic stratigraphy for tracing facies.
1. The document describes the key elements of a petroleum system including the source rock, migration route, reservoir rock, seal rock, and trap that are necessary for oil and gas accumulation.
2. It explains the processes of generation of petroleum from organic-rich source rocks buried deep underground and subjected to heat and pressure over millions of years, and the migration of oil and gas from the source rock into porous reservoir rocks.
3. The document outlines the characteristics of reservoir rocks that allow for the accumulation and storage of oil and gas, as well as cap rocks that form an impermeable seal above reservoir rocks preventing further migration and trapping hydrocarbons below.
Petroleum geology is the application of geology to explore for and produce oil and gas. It relies on understanding rock structures that can trap hydrocarbons underground. Key techniques used include seismic surveys, which use shock waves to map underground rock layers and structures that may indicate oil and gas traps. Important milestones include the development of the anticlinal theory of trapping in 1883, the invention of the seismograph in 1914, and the introduction of 3D seismic in the 1980s to improve imaging of underground structures.
This document discusses secondary migration of petroleum, which is the movement of oil and gas within reservoir rocks after primary migration. The main forces driving secondary migration are buoyancy, as oil and gas are less dense than water, and hydrodynamic forces from water flow. Capillary pressure acts as a resistant force. Secondary migration can occur over distances ranging from hundreds of meters to over 100 km and is facilitated by porous and permeable pathways as well as pressure gradients within the rocks. Water drive and gas flushing are two mechanisms enabling secondary migration to traps and accumulations. Fractures also provide routes for secondary oil and gas to migrate through reservoir strata.
Source rocks are sedimentary rocks that contain significant amounts of organic matter. When buried and heated to sufficient temperatures, this organic matter will generate oil or gas. Effective source rocks contain at least 0.5% total organic carbon and have generated hydrocarbons that have formed commercial oil and gas accumulations. The key characteristics of a source rock are that it contains sufficient quantities and quality of organic matter and reaches the appropriate levels of thermal maturity to generate hydrocarbons. For a source rock to form, conditions must allow for high biological productivity, anoxic conditions to preserve organic matter, and rapid burial of organic-rich sediments.
In this slide basics of Petroleum GEOLOGY is illustrated with the little review of Petroleum and geology terminology.
Also, the responsibilities or role of petroleum Geology is elaborated.
The Cambay Basin is an intracratonic rift graben located in northwest India that began forming following the Deccan Traps volcanic event in the late Cretaceous. The basin is filled with up to 8km of Tertiary sedimentary rocks. Major source rocks include the thick Cambay Shale deposited in the early Eocene during a transgression. Hydrocarbon reservoirs are found in the Olpad Formation, Hazad delta sands, and Miocene formations. Multiple petroleum plays exist, including those in the Paleocene-early Eocene, middle Eocene, and late Eocene-Oligocene sequences. The Cambay Shale is a prolific source of oil and gas in the
This document discusses the key attributes of source rocks: organic richness, kerogen type, and thermal maturity. Organic richness and kerogen type are determined by depositional environment, while thermal maturity depends on tectonic history. Source rocks must contain sufficient organic carbon (>0.5-1% TOC) and be thermally mature to generate hydrocarbons. Kerogen types I-III generate oil, wet gas, and dry gas respectively. Thermal maturity is assessed using indices like Tmax, S1/S2, and spore color. The samples discussed are immature based on their thermal maturity parameters.
This document discusses the origin and formation of oil and gas from plankton and other microscopic organisms. It explains that under low oxygen conditions on the seafloor, organic matter accumulates and is buried over time. Increased temperature and pressure converts the organic matter into kerogen and then into oil and gas. The hydrocarbons can then migrate from the source rock through porous carrier rocks until being trapped by an impermeable cap rock, forming an oil or gas reservoir. Sweet crude oil contains low sulfur while sour crude has higher sulfur levels, affecting refining.
The document discusses a gas dispute between Reliance Industries (RIL) and Reliance Natural Resources Limited (RNRL) over the supply of natural gas from RIL's KG Basin block. RNRL argues it has a right to receive gas from RIL's KG Basin block based on a 2005 family agreement to split assets between two brothers. However, RIL disagrees and a legal battle has ensued over whether RIL must supply gas to RNRL and at what price. The outcome of the court case could significantly impact the revenues and costs of RIL, RNRL, other companies, and influence gas prices in India.
The document provides an overview of petroleum accumulation, including the key components and processes. It discusses:
1) Source rocks containing organic material that is buried and heated, forming oil and gas.
2) Migration of hydrocarbons from source rocks into reservoir rocks via primary and secondary migration processes driven by pressure changes.
3) Reservoir rocks, usually porous sandstone or limestone, that trap hydrocarbons with an impermeable cap rock forming an accumulation. Reservoir rocks must have sufficient porosity and permeability for hydrocarbons to flow.
Petroleum geology refers to the application of geology to explore for and produce oil and gas. It involves analyzing seven key elements of a sedimentary basin: the source, reservoir, seal, trap, timing of maturation and migration. The source rock is evaluated for its organic content and type of kerogen. The reservoir rock is analyzed for porosity, permeability and properties. The seal is a low permeability layer that traps hydrocarbons. Traps are structural or stratigraphic features that ensure hydrocarbons remain trapped. Maturation involves the thermal history to predict hydrocarbon generation and expulsion timing. Refining derives products like gasoline and fuel oil from crude oil through cracking and distillation processes.
Geochemical methods in mineral explorationPramoda Raj
This document discusses geochemical methods for mineral exploration. It covers general principles of geochemistry as they relate to mineral deposits. It also discusses optimizing exploration through proper planning, selection of areas and methods, and organization of field, lab, and supervisory operations. Geochemistry is described as an essential component of modern integrated exploration programs due to the low-grade, large-tonnage nature of most economic deposits and its effectiveness in weathered tropical environments.
This document defines facies as a body of rock characterized by a particular combination of lithology, physical structures, and biological features that distinguish it from surrounding rock. Facies are determined at small scales based on characteristics like grain size, sedimentary structures, color, composition, and fossil content. Facies associations represent depositional environments through combinations of facies. Facies successions show progressive changes in properties that indicate lateral or vertical environmental changes. Facies analysis is used to interpret depositional environments and systems from rock characteristics.
The reservoir (rock porosity and permeability)salahudintanoli
Reservoir rock is the one of the important component in petroleum system i.e without it petroleum system is impossible. This presentation contain all necessary information regarding reservoir rock.
The document summarizes key concepts related to oil and gas reservoirs. It discusses how reservoirs are formed from the remains of ancient organisms subjected to heat and pressure over millions of years. The formation of reservoirs requires sedimentary basins to undergo deep burial, pressure cooking, hydrocarbon migration, and trapping by impermeable rock. Porosity refers to the open space in rock that can hold fluids, while permeability measures the ability of rock to transmit fluids through interconnected pore spaces. Absolute and effective porosity and permeability are defined in relation to single or multiple fluid phases present in the rock.
The document summarizes various sedimentary environments including terrestrial, coastal/marginal marine, and marine settings. It describes key characteristics of fluvial, eolian desert, lacustrine, paludal, deltaic, beach/barrier island, estuarine, lagoonal, tidal flat, continental shelf, continental slope, continental rise, and abyssal plain environments. Sedimentary rocks form under unique physical, chemical, and biological conditions that are determined by factors like water depth, energy levels, sediment sources, and biological activity in each depositional environment.
The document discusses the origin, composition, and types of organic matter found in sediments and rocks. It describes how organic matter originates from organisms and is preserved in anoxic environments. The main types of organic matter discussed are kerogen and bitumen. Kerogen makes up the majority of sedimentary organic matter and has varying potential to generate hydrocarbons upon heating. Bitumen represents the soluble fraction and includes compounds such as asphaltenes and maltens. The document also introduces different types of kerogen that vary in their composition and hydrocarbon generating ability.
Geochemical anomalies in drainage sedimentsPramoda Raj
The document discusses geochemical anomalies found in various types of drainage sediments that can be used for mineral exploration, including spring/seepage sediments, active stream sediments, flood plain sediments, lake sediments, and marine sediments. It explains that drainage sediments provide a sampling medium and anomalies may form from elements precipitating or being eroded, transported, and deposited. The document also notes that lake and marine sediments can indicate mineral deposits based on elements incorporated in sediments or precipitates.
This document discusses reservoir rock, which is subsurface rock with sufficient porosity and permeability to allow for the accumulation of petroleum. It defines porosity as the capacity for rocks to contain fluids, describing primary porosity from spaces between deposited particles and secondary porosity from post-depositional dissolution. Permeability is the ability of fluid to pass through porous rock. Major reservoir rock types include siliciclastic rocks from weathered igneous and sedimentary materials, and marine, lacustrine, and fluvial rocks formed in various depositional environments.
Seismic interpretation and well logging techniquesPramoda Raj
This document provides an overview of seismic interpretation and well logging techniques used in hydrocarbon exploration. It begins with introducing the aims and objectives, which are to understand the principles of seismic interpretation and well log interpretation. It then discusses various topics related to petroleum exploration including basins in India, petroleum systems elements, geophysical exploration methods, seismic surveys, well logging tools, and seismic and well log interpretation. The conclusion emphasizes that the work helped to interpret well logs and seismic sections to understand subsurface lithology and formations.
This document discusses the key geological elements of a petroleum system including source rocks, reservoir rocks, seals, migration routes, and traps. It explains that source rocks contain organic matter that generates hydrocarbons through diagenesis, catagenesis and metagenesis as the rocks are buried deeper. Reservoir rocks have pore spaces that can absorb hydrocarbons, while seal rocks are impermeable layers that trap hydrocarbons between them and the reservoir rock. Traps form where hydrocarbons are blocked from further migrating, such as in structural traps like folds and faults or stratigraphic traps caused by changes in rock layers.
Kerogen is the insoluble organic matter found in source rock that is the precursor to oil and gas. It makes up 1% of shale, with 90% being kerogen. Kerogen forms from organic materials like algae and plants over time under heat, pressure, and other conditions. It exists in four types that can be classified based on their hydrogen to carbon and oxygen to carbon ratios, with types I and II being more oil-prone and type III being more gas-prone. Kerogen is the key starting material in the formation of oil and natural gas deposits.
The document discusses key properties of reservoir rocks including porosity, permeability, and fluid saturation. It defines porosity as the ratio of pore space volume to total rock volume and describes different types of porosity such as primary, secondary, and effective porosity. It also defines permeability as the ability of rocks to transmit fluids and discusses how it is affected by factors like grain size. Additionally, it explains concepts such as critical oil saturation and critical water saturation which refer to saturation levels above which fluids will flow.
Petroleum geology is the study of origin, accumulation, and exploration of hydrocarbon fuels. It refers to the specific set of geological disciplines that are applied to the search for hydrocarbons (oil exploration).
In this slide basics of Petroleum GEOLOGY is illustrated with the little review of Petroleum and geology terminology.
Also, the responsibilities or role of petroleum Geology is elaborated.
The Cambay Basin is an intracratonic rift graben located in northwest India that began forming following the Deccan Traps volcanic event in the late Cretaceous. The basin is filled with up to 8km of Tertiary sedimentary rocks. Major source rocks include the thick Cambay Shale deposited in the early Eocene during a transgression. Hydrocarbon reservoirs are found in the Olpad Formation, Hazad delta sands, and Miocene formations. Multiple petroleum plays exist, including those in the Paleocene-early Eocene, middle Eocene, and late Eocene-Oligocene sequences. The Cambay Shale is a prolific source of oil and gas in the
This document discusses the key attributes of source rocks: organic richness, kerogen type, and thermal maturity. Organic richness and kerogen type are determined by depositional environment, while thermal maturity depends on tectonic history. Source rocks must contain sufficient organic carbon (>0.5-1% TOC) and be thermally mature to generate hydrocarbons. Kerogen types I-III generate oil, wet gas, and dry gas respectively. Thermal maturity is assessed using indices like Tmax, S1/S2, and spore color. The samples discussed are immature based on their thermal maturity parameters.
This document discusses the origin and formation of oil and gas from plankton and other microscopic organisms. It explains that under low oxygen conditions on the seafloor, organic matter accumulates and is buried over time. Increased temperature and pressure converts the organic matter into kerogen and then into oil and gas. The hydrocarbons can then migrate from the source rock through porous carrier rocks until being trapped by an impermeable cap rock, forming an oil or gas reservoir. Sweet crude oil contains low sulfur while sour crude has higher sulfur levels, affecting refining.
The document discusses a gas dispute between Reliance Industries (RIL) and Reliance Natural Resources Limited (RNRL) over the supply of natural gas from RIL's KG Basin block. RNRL argues it has a right to receive gas from RIL's KG Basin block based on a 2005 family agreement to split assets between two brothers. However, RIL disagrees and a legal battle has ensued over whether RIL must supply gas to RNRL and at what price. The outcome of the court case could significantly impact the revenues and costs of RIL, RNRL, other companies, and influence gas prices in India.
The document provides an overview of petroleum accumulation, including the key components and processes. It discusses:
1) Source rocks containing organic material that is buried and heated, forming oil and gas.
2) Migration of hydrocarbons from source rocks into reservoir rocks via primary and secondary migration processes driven by pressure changes.
3) Reservoir rocks, usually porous sandstone or limestone, that trap hydrocarbons with an impermeable cap rock forming an accumulation. Reservoir rocks must have sufficient porosity and permeability for hydrocarbons to flow.
Petroleum geology refers to the application of geology to explore for and produce oil and gas. It involves analyzing seven key elements of a sedimentary basin: the source, reservoir, seal, trap, timing of maturation and migration. The source rock is evaluated for its organic content and type of kerogen. The reservoir rock is analyzed for porosity, permeability and properties. The seal is a low permeability layer that traps hydrocarbons. Traps are structural or stratigraphic features that ensure hydrocarbons remain trapped. Maturation involves the thermal history to predict hydrocarbon generation and expulsion timing. Refining derives products like gasoline and fuel oil from crude oil through cracking and distillation processes.
Geochemical methods in mineral explorationPramoda Raj
This document discusses geochemical methods for mineral exploration. It covers general principles of geochemistry as they relate to mineral deposits. It also discusses optimizing exploration through proper planning, selection of areas and methods, and organization of field, lab, and supervisory operations. Geochemistry is described as an essential component of modern integrated exploration programs due to the low-grade, large-tonnage nature of most economic deposits and its effectiveness in weathered tropical environments.
This document defines facies as a body of rock characterized by a particular combination of lithology, physical structures, and biological features that distinguish it from surrounding rock. Facies are determined at small scales based on characteristics like grain size, sedimentary structures, color, composition, and fossil content. Facies associations represent depositional environments through combinations of facies. Facies successions show progressive changes in properties that indicate lateral or vertical environmental changes. Facies analysis is used to interpret depositional environments and systems from rock characteristics.
The reservoir (rock porosity and permeability)salahudintanoli
Reservoir rock is the one of the important component in petroleum system i.e without it petroleum system is impossible. This presentation contain all necessary information regarding reservoir rock.
The document summarizes key concepts related to oil and gas reservoirs. It discusses how reservoirs are formed from the remains of ancient organisms subjected to heat and pressure over millions of years. The formation of reservoirs requires sedimentary basins to undergo deep burial, pressure cooking, hydrocarbon migration, and trapping by impermeable rock. Porosity refers to the open space in rock that can hold fluids, while permeability measures the ability of rock to transmit fluids through interconnected pore spaces. Absolute and effective porosity and permeability are defined in relation to single or multiple fluid phases present in the rock.
The document summarizes various sedimentary environments including terrestrial, coastal/marginal marine, and marine settings. It describes key characteristics of fluvial, eolian desert, lacustrine, paludal, deltaic, beach/barrier island, estuarine, lagoonal, tidal flat, continental shelf, continental slope, continental rise, and abyssal plain environments. Sedimentary rocks form under unique physical, chemical, and biological conditions that are determined by factors like water depth, energy levels, sediment sources, and biological activity in each depositional environment.
The document discusses the origin, composition, and types of organic matter found in sediments and rocks. It describes how organic matter originates from organisms and is preserved in anoxic environments. The main types of organic matter discussed are kerogen and bitumen. Kerogen makes up the majority of sedimentary organic matter and has varying potential to generate hydrocarbons upon heating. Bitumen represents the soluble fraction and includes compounds such as asphaltenes and maltens. The document also introduces different types of kerogen that vary in their composition and hydrocarbon generating ability.
Geochemical anomalies in drainage sedimentsPramoda Raj
The document discusses geochemical anomalies found in various types of drainage sediments that can be used for mineral exploration, including spring/seepage sediments, active stream sediments, flood plain sediments, lake sediments, and marine sediments. It explains that drainage sediments provide a sampling medium and anomalies may form from elements precipitating or being eroded, transported, and deposited. The document also notes that lake and marine sediments can indicate mineral deposits based on elements incorporated in sediments or precipitates.
This document discusses reservoir rock, which is subsurface rock with sufficient porosity and permeability to allow for the accumulation of petroleum. It defines porosity as the capacity for rocks to contain fluids, describing primary porosity from spaces between deposited particles and secondary porosity from post-depositional dissolution. Permeability is the ability of fluid to pass through porous rock. Major reservoir rock types include siliciclastic rocks from weathered igneous and sedimentary materials, and marine, lacustrine, and fluvial rocks formed in various depositional environments.
Seismic interpretation and well logging techniquesPramoda Raj
This document provides an overview of seismic interpretation and well logging techniques used in hydrocarbon exploration. It begins with introducing the aims and objectives, which are to understand the principles of seismic interpretation and well log interpretation. It then discusses various topics related to petroleum exploration including basins in India, petroleum systems elements, geophysical exploration methods, seismic surveys, well logging tools, and seismic and well log interpretation. The conclusion emphasizes that the work helped to interpret well logs and seismic sections to understand subsurface lithology and formations.
This document discusses the key geological elements of a petroleum system including source rocks, reservoir rocks, seals, migration routes, and traps. It explains that source rocks contain organic matter that generates hydrocarbons through diagenesis, catagenesis and metagenesis as the rocks are buried deeper. Reservoir rocks have pore spaces that can absorb hydrocarbons, while seal rocks are impermeable layers that trap hydrocarbons between them and the reservoir rock. Traps form where hydrocarbons are blocked from further migrating, such as in structural traps like folds and faults or stratigraphic traps caused by changes in rock layers.
Kerogen is the insoluble organic matter found in source rock that is the precursor to oil and gas. It makes up 1% of shale, with 90% being kerogen. Kerogen forms from organic materials like algae and plants over time under heat, pressure, and other conditions. It exists in four types that can be classified based on their hydrogen to carbon and oxygen to carbon ratios, with types I and II being more oil-prone and type III being more gas-prone. Kerogen is the key starting material in the formation of oil and natural gas deposits.
The document discusses key properties of reservoir rocks including porosity, permeability, and fluid saturation. It defines porosity as the ratio of pore space volume to total rock volume and describes different types of porosity such as primary, secondary, and effective porosity. It also defines permeability as the ability of rocks to transmit fluids and discusses how it is affected by factors like grain size. Additionally, it explains concepts such as critical oil saturation and critical water saturation which refer to saturation levels above which fluids will flow.
Petroleum geology is the study of origin, accumulation, and exploration of hydrocarbon fuels. It refers to the specific set of geological disciplines that are applied to the search for hydrocarbons (oil exploration).
transformation of organic matter into kerogen.pptxRonitKumam
- Petroleum is formed from the remains of ancient organisms that are transformed into kerogen and eventually hydrocarbons through geological processes over millions of years.
- Key factors that influence petroleum formation include the type and amount of organic matter deposited, the environmental conditions that allow for preservation of organic matter, and the rate and depth of burial which determines the temperature and pressure the organic matter experiences.
- As organic matter is buried deeper in sediments, the increasing heat and pressure causes kerogen to crack and thermally degrade first into liquid and gaseous hydrocarbons through catagenesis. Further heating in metagenesis converts more kerogen into methane and a carbon residue.
Physical and Chemical Properties of HydricarbonsMasoom Shani
The document discusses the physical and chemical properties of petroleum. It defines various types of hydrocarbons such as oil, natural gas, condensates, and their classification. It describes the composition of natural gas and crude oil. It also discusses the key terms used in petroleum geology such as source rock, reservoir rock, seal rock, and the refining process.
Fundamentals of Petroleum Engineering Module-1Aijaz Ali Mooro
This document provides an introduction to the fundamentals of petroleum engineering. It outlines the key topics that will be covered, including what petroleum engineering entails, how petroleum is formed and its chemical composition, fractional distillation processes for crude oil, the history of oil production in Nigeria, and an overview of production sharing contracts. The learning objectives are to understand the basics of the petroleum engineering field and various upstream oil and gas industry concepts and processes.
This document provides an overview of fuels and combustion for power plant engineering. It discusses the main types of fuels used in power plants including solid fuels like coal, gaseous fuels like natural gas, and liquid fuels derived from petroleum. For each fuel type, it describes important properties that influence combustion such as density, viscosity, heating value, and ash content. The document also covers the principles of combustion like stoichiometric air-fuel ratios and the conditions required for complete combustion. Key concepts discussed include the proximate and ultimate analysis of coal and the combustion of hydrocarbon fuels.
Petroleum, also known as crude oil, is a naturally occurring liquid found beneath the Earth's surface. It is composed primarily of hydrocarbons such as carbon and hydrogen. Crude oil is extracted from the ground through oil wells, either because it flows naturally due to underground pressures or through mechanical pumping. There are several theories for the origin of petroleum, but the modern theory is that it formed from the decomposition of marine organisms and terrestrial plant material over millions of years. Once extracted, crude oil undergoes processing to remove impurities and separate it into useful petroleum products through distillation. These products include fuels like gasoline, diesel and jet fuel, as well as other commodities like lubricating oils, asphalt and
Petroleum, also known as rock oil, is a naturally occurring complex hydrocarbon found underground. It exists in solid, liquid, and gaseous forms. Commercial deposits are always found underground in sedimentary rocks. Petroleum is formed from the remains of ancient organisms over millions of years. It is known as a fossil fuel and "liquid gold" due to its economic value. Crude oil and natural gas deposits are found through petroleum exploration of sedimentary basins around the world. India contains 26 sedimentary basins covering over 3.5 million square kilometers that are categorized based on their hydrocarbon prospectivity and production status.
The document discusses the origin, composition, and classification of petroleum. It states that modern theories indicate petroleum originated from the decomposition of ancient marine and terrestrial organisms buried under high pressure and temperature deep underground. Petroleum is composed mainly of hydrocarbons like paraffins, naphthenes, and aromatics, along with small amounts of other organic compounds. It is classified based on the types of hydrocarbons present and can be paraffinic, naphthenic, asphaltic, or a mixture. Fractional distillation is used to separate crude oil into different fractions like gasoline, kerosene, and diesel fuel.
This document provides an overview of petroleum refinery engineering. It discusses the origin and composition of crude oil, refinery processes like distillation, cracking and reforming. It covers auxiliary operations, product design and the use of linear programming. Key terms like petroleum, refining, distillation, cracking and reforming are defined. Recommended books on petroleum refinery technology and economics are also listed.
This document provides an overview of petroleum refinery engineering. It discusses the origin and composition of crude oil, refinery processes like distillation, cracking and reforming, and auxiliary operations. It also lists recommended books and introduces concepts like crude oil properties, hydrocarbon groups, non-hydrocarbon compounds, origin of hydrocarbons, exploration techniques, and physical properties of crude oil.
This document provides information about the composition of crude oil, including:
1. Crude oil is composed primarily of hydrocarbon compounds like alkanes, cycloalkanes, and aromatic hydrocarbons. It also contains smaller amounts of other organic compounds containing sulfur, nitrogen, and oxygen, as well as trace metals.
2. The specific molecular composition varies between crude sources, but on average crude oil is 83-87% carbon, 10-14% hydrogen, and contains 0.1-6.0% sulfur and 0.1-2.0% nitrogen.
3. Other hydrocarbon groups found in crude include paraffins (alkanes), naphthenes (cycloalkanes), and aromatic
Petrochemicals are chemicals derived from petroleum products. They include plastics, rubbers, fibers, paints, solvents and detergents. Petrochemicals are produced from purified hydrocarbon feedstocks separated from crude oil. Feedstocks undergo cracking and other processes to produce intermediates like ethylene and propylene. These intermediates are then polymerized and further processed to create finished petrochemical products like polymers, resins and solvents.
Physical and chemical properties of petroleumMasoom Shani
This document discusses the physical and chemical properties of petroleum. It defines petroleum as a mixture of hydrocarbons that are mostly liquid, but can also be in gas or solid states. The four main hydrocarbon series in petroleum are paraffins, naphthenes, aromatics, and asphaltenes. Key physical properties discussed include specific gravity, viscosity, refractive index, color, odor, and boiling point. The document also describes how petroleum can be classified based on its relative amounts of different hydrocarbon groups.
Petroleum is a naturally occurring flammable liquid consisting of hydrocarbons found underground. It is extracted through oil drilling and refined into many consumer products through fractional distillation. Crude oil varies in composition but largely includes paraffins, naphthenes, and aromatics. Octane and cetane ratings indicate gasoline and diesel fuels' resistance to knocking during combustion in engines. Synthetic petrol can also be produced through processes like Fischer-Tropsch that use coal, steam, and catalysts to synthesize hydrocarbon fuels.
Crude oil, also known as black gold, is a complex mixture of hydrocarbons found in sedimentary rocks. It is believed to have formed from the remains of ancient plants and animals over millions of years. Crude oil is composed mainly of paraffin hydrocarbons, along with other components like naphthenes, aromatics, asphaltenes and various chemical elements. The four main categories of hydrocarbon types in crude oil are paraffins, olefins, naphthenes and aromatics, which have varying molecular structures and properties. Crude oil can also contain small amounts of sulfur, nitrogen, oxygen and heavy metal compounds.
This document provides information on the composition of crude oil. It discusses that crude oil is a mixture of hydrocarbons that is liquid underground but varies in color from yellow to black. It is composed primarily of carbon and hydrogen. The main components are paraffins, naphthenes, and aromatics. Crude oil also contains smaller amounts of other elements and compounds like sulfur. The document also describes different methods of classifying crude oils based on their chemical composition and geological parameters.
The document provides an outline for a workshop on hydrocarbons. It discusses what hydrocarbons are, how they are formed, their types and characteristics. It describes how hydrocarbons are non-renewable, non-polar compounds consisting of carbon and hydrogen. It explains that hydrocarbons are formed through the bonding of carbon and hydrogen atoms and can exist in various states. The document also addresses the environmental issues posed by hydrocarbons and techniques for their degradation and bioremediation.
Petroleum forms over millions of years from the remains of ancient marine organisms that are buried underground and exposed to heat and pressure. It is composed mainly of hydrocarbons and varies in composition between regions. Crude oil is classified based on location, density, and sulfur content. Light, low-sulfur crude is most valuable as it yields more gasoline and diesel during refining. Refining separates crude into fractions by boiling point and converts heavier fractions into gasoline and other fuels through cracking. Around 42% of a barrel of crude becomes gasoline.
Carbon and its compounds Chapter SEE Science NepalAnjan Nepal
- The document discusses different types of hydrocarbons including alkanes, alkenes, and alkynes. It also discusses functional groups, homologous series, and IUPAC nomenclature rules.
- Specific hydrocarbons like methane, ethane, propane, butane, alcohols, glycerol, and glucose are explained. Their chemical formulas, structures, properties and common uses are provided.
- Isomerism in hydrocarbons is introduced, with butane given as an example to illustrate structural isomers.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
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How to Make a Field Mandatory in Odoo 17Celine George
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Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
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Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
2. Fundamentals Petroleum Geology
• It is an applied geoscience discipline that involves
the study of:
– The origin
– Generation
– Migration
– Accumulation; of HC’s with a view to defining ways to
successfully explore and produce it
• In involves the integration of basic geology
disciplines such as: sedimentology, stratigraphy,
structural geology, mineralogy, geochemistry,
geophysics, palynology, paleontology, etc., and
other pure science disciplines
2
4. What is petroleum
Latin; Petra: ROCK; Oleum: OIL
Petra + oleum = rock oil
‘’A naturally occurring liquid, gas, semi-solid or solid
mixture of hydrocarbon and non-hydrocarbon
molecules.”
• The aforementioned suggests petroleum can occur
as:
– liquid (crude oil)
– Gas (natural gas)
– Solid and semi-solid (Asphalt, Bitumen, Tar, etc.)
4
5. Natural Gas
• Petroleum in gaseous state; ‘it is the lightest form of
petroleum with little complexity’
• It can also be defined as petroleum that is non-
condensable at ≥ 200
C and atmospheric conditions (i.e.
at ῀ surface conditions)
• Can be classified as dissolved gas (if it occurs in solution
in crude oils); associated gas or ‘gas cap’ (above oil
column in HC reservoirs); or non associated gas or ‘NAG’
(no associated oil column)
• Natural gas can also be termed as Wet gas (methane +
ethane, propane and butane and other higher HC’s ) if
it contains liquid oil vapour (i.e. ≥ 0.3 gal/1000ft3 of
condensate) or Dry gas (mainly methane) if it contains
very little or no liquid oil vapour (i.e. ≤ 0.1 gal/1000ft3 of
condensate) 5
6. • Natural gas may exist as liquids (Natural gas liquids) at
the surface under certain conditions. These are termed:
– Liquefied Petroleum gas (LPG): natural gas (that
exist normally in gaseous state at STP) liquefied and
condensed at very low T and High T. chemically,
LPG is mainly propane and butane
– Condensate: wet gas; liquid at STP. Chemically,
condensate comprises of Pentanes and other higher
HC’s
• Occurrences of non HC gases like He, H2S, Ar, H,
Co2,O2, etc have been reported in association with
Natural gas.
6
7. Crude oil
• Liquid HC at reservoir and surface conditions
• Vary in colour from yellow through green to brown
and black
• It is insoluble in water; its solubility is inversely
proportional to its carbon number
• Commonly has some dissolved gas in it
• Crude oil is said to be saturated when no more gas
can be taken into solution i.e. an associated gas
column (gas cap) exist with it at reservoir levels
• It is unsaturated if there’s still potential for natural gas
to be dissolved in it
• It has a wide range of SG (i.e from heavy oil to light
oil) and viscosity
7
8. Petroleum chemistry
Molecular groups of hydrocarbons:
• Paraffins = alkanes (aliphatics)
• Napthenes (cycloparaffins) = cycloalkanes
• Aromatics = arenes
• Naphtheno-aromatics (complex polycyclic molecules)
• Olefins = alkenes
Paraffins = alkanes (aliphatics)
• Can occur as straight chain (normal alkanes) or branched
chain (iso-alkanes)
• Saturated HC’s (all carbon bonds (C-C) are saturated with
hydrogen) with a general formula of CnH2n + 2, where n =
1– >60
• n = 1–4 are gases (1-3 dominate natural gas); n = 5–17 are
mainly liquids (dominate gasoline fraction of petroleum) n =
> 17 are waxes, semi-solids, asphalts, etc.
• They form a homologous series (each successive member
differ by CH2)
8
9. Isoparaffins
• Isomers of n-paraffins
•same composition and same general formula with n-paraffins
• differ in structure, physical and molecular properties
9
10. Naphthenes (cycloparaffins)
• Saturated; general formula of : CnH2n
• C-atoms are joined in a ring
• Dominant structures in petroleum
• Form a homologous series up to n=30
• Generally, rings greater than C7 are unstable and become
strained in crude oil
10
11. Aromatics (arenes)
• Unsaturated; General formula: CnH2n-6r (where r =
number of benzene rings)
• They react to add CH3 (akyl benzene) to the ring (i.e. H
atoms can be substituted; soluble in water)
• mainly found in heavy fractions.
• Toluene is most common form.
11
13. Olefins (alkenes)
• Unsaturated with General formula of CnH2n
• Form homologous series
• Rare in natural crudes—normally reduced to paraffins
• highly reactive
13
14. Asphaltics – NSO Compounds
• Non HC’s; abundant in the heavy solid to semi solid
residual fractions of petroleum; may also be present
in lighter HC’s (crude oil).
• As a rule of thumb, the lower the °API Gravity
(higher the viscosity), the higher the proportion of
NSO-compounds
Examples include:
Nitrogen Compounds
• Pyridines
• Quinolenes
• Indoles
Range in natural crude oils: < 0.25–0.8% N
14
15. Sulphur compounds
• most abundant after HC’s
• Thiols (mercaptans)
• Thoiophenes
• Free S and H2S
Range in natural crude oils: < 0.5–5% S
Oxygen Compounds
• Common in Immature oils
• Organic acids
• Alcohols, phenols, esters
• Indoles
Range in natural crude oils: < 0.1–2.0% O
Other components include various metallic
compounds, spores, altered microfossil remains
(geochemical fossils or biomarkers), etc.
15
16. Proposed classification of crude oils on the basis of relative
proportions of alkanes, cyclo-alkanes, and aromatics plus
NSO compounds (Tissot and Welte, 1984) 16
17. Properties of Petroleum
Specific Gravity
• A measure of the weight of a given material compared to the
weight of an equal volume of water at standard temp & pressure
• The degree API or API is the Industry standard scale of measure.
It relates to SG by: “API0
= (141.5/S.G) - 131.5’’
17
18. • API is used as an index to adjust the prices of crude
Viscosity
• Measures the fluid’s resistance to flow. It is affected by the
amount of dissolved gases in the oil at a definite T &P.
Viscosity is measured in centipoises (cp = 10-2
poise).
Pour Point
• Measures the lowest temperature at which a crude oil will
flow, just before it starts to turn into a solid. Generally, the
higher the paraffin content of a crude the higher will be the
pour point. Lower pour point is preferred to higher pour point.
Colour
• Crude oils vary in colour from colourless (very light crudes)
to greenish-yellow to reddish to black (generally the heavy
crudes).
18
19. Odour
• Various crudes oils smell like gasoline (sweet crudes) or
rotten eggs (sour crudes) or have a sickly fruity smell
(aromatic crudes).
Cloud point
• Defined as “ the Temp. at which the first cloud appears during
cooling of heated oil”. It is a consequence of settling out of
paraffin waxes. N/B: non waxy crudes show no cloud point
Flash point & Burning point
• Flash point is ‘the temperature at which vapour rising from a
heated oil will be ignited with a flash of short duration when a
flame is passed over it
• Burning point is the lowest temperature at which a heated oil
will ignite and burn with a steady flame
(these props. are useful when evaluating potential hazards
of handling and storing crude oil)
19
20. Fluorescence
• Hydrocarbons usually emit visible light (fluoresces) when
exposed to UV light. Colour ranges from green to light blue. This
fluorescence property comes in handy when looking for evidence
of oil shows in cuttings or cores
Refractive index
• This is a function of the density and temperature of crude oils. It
is the ratio of the velocity of light through the crude to the
velocity of light through a vacuum. It ranges from 1.39 – 1.50
Optical activity
• Certain compounds possess the ability to rotate the plane of
polarization either to the right or left. This property is called
optical activity. It is a property exhibited by petroleum as a result
of its porphyrin content. Porphyrins are the organometallic
derivatives of haemin (animal) and chlorophyll (plants)
20
21. Origin of Petroleum
Inorganic hypothesis
• This hypothesis is mainly supported by the Russians
• Evidences to support this hypothesis are:
– Discovery of methane in atmospheres of Jupiter, Saturn and
Neptune; occurrence of carbonaceous chondrites
– Occurrence of petroleum in basement rocks
– Production of methane during volcanism
– Petroleum synthesized in the Laboratory:
FeC2 + 2H2O = C2H2 [acetylene] + Fe(OH)2
Al4C3 + 12H2O = 3CH4 + 4Al(OH)3
Fischer-Tropsch reaction:
CO2 + H2 = CO + H2O, then CO + 3H2 = CH4 + H2O
The inorganic hypothesis has now been laid to rest. A lot
of scientists now favour an organic origin for petroleum
21
22. • The inorganic hypothesis has now been laid to rest.
• A lot of scientists now favour an organic origin for petroleum
Some Organic evidences for petroleum
• Poor correlation between petroleum and volcanism
• Paucity of Precambrian oil
• Isotopic evidence favours organic origin
• Petroleum is “optically active” – linked to organic origin
• Presence of homologous series
• Geological association of petroleum with sedimentary
basins
• Presence of organic debris (foram test, lignite) and
geochemical fossils (biomarkers)
• Petroleum are very complex hydrocarbons. This reflects the
great variability of the primary source material and
differences in the physio-chemical conditions that persisted
during petroleum generation and migration
22
23. Petroleum occurrence
• Petroleum occurs either on the surface or in the sub-surface
Surface occurrences
• Are mainly petroleum springs and seepages found on land
and underwater;
• flow of petroleum in seeps is usually very slow (sluggish),
whereas in Springs, it is reasonably rapid are
• Their occurrence is indicative of a working petroleum system
(effective SR), and potential subsurface accumulations
• Usually, evaporation/biodegration of petroleum (crude oil) in
these occurrences leave behind viscous residues (Tar,
bitumen, asphalt, etc)
23
24. Subsurface occurrences
• These are the main targets of any exploration campaign
• Subsurface accumulations can only take place if all the
geologic conditions are met (timing of elements and
processes of a petroleum system)
• they can be minor showings or major (commercial) finds.
• petroleum usually accumulates in Pools within the Fields in
a Petroleum Province.
• A pool of oil is the simplest unit of commercial occurrence. ‘It
is an accumulation of petroleum in the same reservoir
and trap, under the same pressure and temperature
conditions
• Several petroleum pools related to same geological
features is a field
• These geologic features can be structural or
stratigraphic.
• Very large fields are called Giants.
24
26. • By now we know Petroleum is generated in organic rich
fine grained sedimentary rocks
• Tissot (1977) outlined 3 stages in conversion of OM in the
source rocks to Petroleum
• These stages are:
Diagenetic stage
• This takes place at temp. up to ῀650C & low pressures;
depths from sediment interface up to 2km (depending of
the geothermal gradient of the basin)
• OM matter is broken down firstly biogenically (aided by
aerobic bacteria using up all trapped oxygen in the fine
grained sediments)
• And thereafter abiogenically (aided by anaerobic bacteria),
reducing nitrates, nitrites and sulphates
• The end product is Kerogen (a complex insoluble HC),
swamp gas/biogenic gas/dry gas (methane) + CO2 and
H2O (other non HC gases include NH3, H2S and P2O5
26
27. Nitrate Reduction
• After oxygen is depleted, NO3
- is used as an energy source:
6CH2O + 4NO3
- = 6CO2 + 6H2O + 2N2
When nitrate is exhausted:
Sulphate Reduction
2CH2O + SO4
2- = H2S + 2HCO3
-
SO4
2- = S + 2O2 (mainly by Desulfovibrio bacteria)
• If iron is available in the sediment, H2S may combine with
Fe to form pyrite.
• Consequently, pyrite is so commonly associated with in
black, organic-rich shales and coal
• In the absence Fe or other metallic ions, the H2S may or
may combine with organic molecules.
• This can result in an S-rich crude oil
27
28. Methanogenesis (fermentation)
• Methanogens produce CH4 from the residue of the overlying
zones:
CH3COOH (cellulose) = CH4 + CO2 (acetate fermentation)
CO2 + 8H+ = CH4 + 2H2O (CO2 reduction)
The early microbial reactions:
• remove much of the N, S, O, and P
• Enrichment of C and H in the residue (it is a reduction
process)
• Residual organic products (lipids and lignin) following
anaerobic diagenesis continue to transform into kerogen
• Kerogen is formed by partial destruction and rebuilding of the
organic building blocks (polycondensation)
• Humic substances which gives fine grained sediments a dark
colour (humic and fulvic acid) is formed in this process
28
29. • Humic substances are partially soluble in water.
• Further condensation (insolubilization) eliminates much of the
remaining nitrogen and converts the humic substances into
insoluble kerogen.
Catagenetic stage
• With increasing burial, T and P increases
• The OM (Kerogen) is thermally cracked; complex
kerogen structure is broken (i.e. maturation takes place)
• Petroleum is generated: mainly oil in the early stage,
then oil and gas (wet gas) at the late stage
• This leads to a reduction in H:C ratio, TOC and S2
• S1 increases
• All these occurs between T ῀ 65oC - ῀175oC and depths of
between ῀1km – ῀3.5km (depending of the geothermal
gradient of the basin)
29
30. Metagenetic stage
• At greater T, P and depth of burial, C-C bonds are further
broken down (cracked)
• H:C ratio, TOC and S2 decreases further
• S1 increases
• The only HC produced at this stage is methane (dry gas)
• Source rocks lose their HC generation potential and
overmature
• The end result is a carbon residue - graphite
There are several ‘paleothermometers’ that can be used to
track the stages of conversion of OM through Petroleum to
graphite (carbon residue). Some of which have been
previously mentioned. Others include:
• Clay diagenesis
• TR
• Fluid inclusion
• Gas chromatography (evolution of n-alkanes), etc.
30
31. HC generation at different
depths conditioned by
geothermal gradient (Pusey,
1973)
Stages in thermal maturation
(Tissot and Welte, 1978)
31
32. Correlation of HC generation with some paleothermometers
(Selley, 1998) 32
34. Petroleum alteration
• The initial physico-chemical properties of petroleum
is often times adjusted (altered) by new set of
conditions encountered in petroleum reservoirs
(Blanc and Connan, 1993)
• The processes bringing about these changes can
be summed into the underlisted:
• Changes due to biodegradation/water washing
• Changes due to thermal alteration
• Changes due to de-asphalting
• Phase segregation
34
35. 35
Effects on the API gravity by differences in source rock-types and by
alteration processes post-dating the accumulation
(Tissot and Welte, 1984)
38. Case study: Niger Delta
• Evamy et al.(1978) found out that in some fields,
heavy oil was found in shallow reservoirs while
lighter oil was found at deeper levels
• Dickey et al. (1987) studied Imo River, Odidi,
Afiesere, Batan, Oroni and Agbada fields and
observed the change from heavy to light crude
is often dramatic
• Furthermore, heavy oil was found to be
associated with meteoric, connate and mixed
water (no link with meteoric water and heavy oil)
• Undegraded oil was found with meteoric water.
38