Oil & Gas Flashcards
How many litres in a barrell of oil
159
What are the marketable products from an oil well?
Oil, natural gas or condensates
How much Kerogen in source rock sufficient for commercial exploitation of crude oil and natural gas?
Kerogen concentrations as low as 1%–3% are generally sufficient to be make source rock (typically shales and limestones) suitable for commercial exploitation of crude oil and natural gas.
What does the term “oil window” refer to?
describe the range of temperature or depth within which most of oil’s complex constituents are produced (fig. 1–1).This window is typically 80–220°C (176–428°F) or 2,200– 5,500 meters (7,200–18,000 feet).
What are the drivers for the conversion of kerogen in source rock to oil and gas?
The key factor is temparature. Other factors include pressure, and the presence of hydrogen and water. As these various drivers exert their influence, the kerogen in source rock undergoes conversion to petroleum in a process called “maturation”
What is meant by ‘maturation’?
The conversion of kerogen in source rock to oil/gas
What is meant by ‘migration’?
when oil and gas move from source rock into a reservoir. virtually all commercially viable oil reservoirs result from migration that takes the hydrocarbons away from the source rock and into reservoir rock.
What are hydrocarbon traps?
structural, stratigraphic, and combination traps prevent the movement of hydrocarbons from source rock into reservoirs.
What is crude oil often found along with?
Crude oil is often found along with natural gas and saline (salty) water.
What are the three parameters used to classify crude oil?
Geographic location in which it is produced (which affects the cost of transporting the crude to a refinery).
• API gravity (an oil industry measure of density;API is the American Petroleum Institute). Light crude oil has relatively low density; heavy crude has high density. Oil with an
API gravity (expressed as oAPI) below 10.0 is classified
as extraheavy.
• Sulfur content. Crude is generally called sweet if it contains relatively little sulfur or sour if it contains substantial amounts.
What is the difference between a sweet and sour oil?
Sulfur content. Sweet oils contain relatively little sulfur and sour oils contain substantial amounts
Why does sweet command a higher premium than sour?
because it has fewer environmental problems and requires less refining to meet sulfur-content standards imposed by buyers
Each crude oil has unique molecular characteristics that are evaluated by a process called __________?
assay analysis
What is West Texas Intermediate?
a very high quality sweet, light oil delivered at Cushing, Oklahoma, for North American oil. Cushing is the delivery point for WTI traded on the New York Mercantile Exchange (NYMEX), the most widely traded oil futures contracts in the world.
What is Brent Blend?
made up of 15 oils from fields in the Brent and Ninian systems in the East Shetland Basin of the North Sea. Oil production from Europe and Africa, as well as Middle Eastern oil flowing to the West, tends to be priced using this benchmark.
What is Dubai-Oman?
Dubai-Oman, used as benchmark for Middle East sour crude flowing to the Asia-Pacific region.
What is the OPEC reference basket?
a weighted average of oils and blends from the 12 nations that make up the Organization of the Petroleum Exporting Countries.
What are the unconventional types of crude oil?
Tar Sands and Shale Oil?
What are tar sands?
A kind of heavy crude oil. Tar sands contain bitumen. he sticky, black, tarlike material is so thick that it must be heated or chemically diluted before it will flow
Which countries have the highest sources of Tar sands?
Canada and Venezuela contain an estimated 3.6 trillion barrels (570 billion cubic meters) of bitumen and extraheavy oil.This represents about twice the volume of the world’s reserves of conventional oil.
What is shale oil.
Trapped kerogen in relatively hard rocks called marks (composed primarily of clay and calcium carbonate). The trapped kerogen can be converted into crude oil using heat and pressure to simulate natural processes.
Where are oil shales found?
Many countries but the USA has the largest deposits.
What are the 3 types of wells where gas comes from?
oil wells, gas wells, and condensate wells.
What is Natural gas that comes from oil wells is typically termed?
“associated gas.
Natural gas from gas and
condensate wells in which there is little or no crude oil, is termed what?
Non Associated Gas
What do condensate wells produce?
free natural gas along with a semi-liquid hydrocarbon condensate
What other hydrocarbons is often found in natural gas?
it commonly exists in mixtures with other hydrocarbons, principally ethane, propane, butane, and pentanes (“Associated Hydrocarbons”)
What other compunds are found with natural gas?
water vapor, hydrogen sulfide (H2S), carbon dioxide, helium,
nitrogen, and other compounds
What are typical byproducts of natural gas processing?
ethane, propane, butane, …known as Natural Gas liquids
What does the midstream part of the value chain typically include?
gas plants, LNG production and regasification, and oil and gas pipeline transport systems
What are Subsea production systems?
wells located on the sea floor as opposed to the surface. the petroleum is extracted
at the seabed, and is then “tied-back” to a pre-existing production platform or
even an onshore facility, limited by horizontal distance or “offset”/
When are subsea systems use? Do these systems hav the ability to drill?
Subsea systems are typically used at depths of 500
meters or more and do not have the ability to drill, only to extract and transport. Drilling and
completion is performed from a surface rig
What are manifolds and gathering systems?
The
purpose of these pipelines is to allow setup of
production “well sets” so that for a given production
level, the best reservoir utilization well flow
composition (gas, oil, water), etc., can be
selected from the available wells.
How are gas, water and oil separated?
Classic form is a gravity seperator. In gravity separation, the well flow is fed into a horizontal vessel. The
retention period is typically five minutes, allowing gas to bubble out, water to settle at the bottom and oil to be taken out in the middle
What is gas processing?
Gas processing consists of separating the various
hydrocarbons and fluids from the pure natural gas to
produce what is known as “pipeline quality” dry natural
gas.
What are Natural Gas Liquids and what are they used for?
Associated hydrocarbons, known as “natural gas liquids” (NGL) are ethane, propane and butane and are used as
raw materials for oil refineries or petrochemical plants and as sources of energy.
Why is gas compression required?
Gas from a pure natural gas wellhead might have
sufficient pressure to feed directly into a pipeline
transport system. Gas from separators has generally lost so much pressure that it must be recompressed to
be transported
how are gas pipelines inspected for corrosion and defects?
With Pigs. Pigs are intelligent
robotic devices that are propelled down pipelines to evaluate the interior of the pipe. Pigs can test pipe thickness, roundness, check for signs of
corrosion, detect minute leaks, and any other defect along the interior of the pipeline that may either restrict the flow of gas, or pose a potential safety risk
Why is liquification of gas carried out?
the only practical solution to long distance
gas transportation whena pipeline is not available
or economical is to produce LNG at -162 °C. at the receiving end, a regasification terminal heats the
LNG to vaporization for pipeline distribution
What is one of the important features of a successful refiner?
The economic success of a
modern refinery depends on its ability to accept
almost any available crude.
