Oil – Formation to Production
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boem.gov/National-Program/ • Crude oil is a mixture of hydro- carbons that formed from plants and animals that lived millions of years ago. • Over the years, the remains were covered by layers of sediment. • Heat and pressure from these layers helped the remains turn into crude oil. • Crude oil exists in liquid form in underground pools or reservoirs, in tiny spaces within sedimentary rocks. • After the oil forms, it rises from a source rock through fractures in the subsur- face due to the relatively low density of oil. • The rising oil then migrates to a reser- voir rock, that contains tiny spaces called pores. • The oil remains in a reservoir rock when there is an overlying cap rock through which oil cannot pass. • The lifecycle of offshore oil and gas activities is a multi-year process consisting of various phases. • Once production begins it may continue for several decades. • The timing of the activities varies by region. • Mature areas like the Gulf of Mexico take relatively shorter time; frontier areas like the Arctic could take a longer time. Example of Activities and Timeline for a Deepwater Offshore Project How is Oil Found? • Hydrocarbon resources are found using exploration techniques such as seismic imaging. • Seismic imaging assists in identifying the potential areas that may contain oil and gas. • If an area is identified as a prospective reservoir, an exploratory well is drilled to test for the presence of hydro carbon resources. How is Oil Produced? • Once an oil pool is discovered, delineation wells are drilled to characterize the size of the accumulation. • Production facilities are then fabricated and installed to extract the oil. • Different types of facilities exist, based on water depths, to safely produce and transport the oil to shore. Geophysical and Data Acquisition and Analysis Lease Sale Exploratory and Development Drilling Design, fabrication and installation First Oil Production Buoy Acoustic Receivers (Streamers) Sound Wave Source Sound Waves Sound Reflection Surface Soiil Layers Seismic Survey Vessel What is Oil? How is it Formed? ~ 3500 ft ~ 4 miles YEAR 1 YEAR 11-15 YEAR 16 ONWARDS YEAR 6-10 YEAR 2-5 Oil – Formation to Production Oil PRESSURE increases as layer on layer of sediments deposit As more sediments accumulate, pressure and heat builds. Hydrocarbons begin to form eventually becoming crude oil Sea bed Sea bed Oil rig Cap rock Impermeable Oil drawn to the surface Oil comes up under pressure Sedimentary rocks Crude oil trapped in pores in reservoir rock Particles of mud, plant & marine animal matter form layers of sediments Approximately 100 Million Years Ago Present Day
Transcript of Oil – Formation to Production
boem.gov/National-Program/
• Crude oil is a mixture of hydro-carbons that formed from plants and animals that lived millions of years ago.
• Over the years, the remains were covered by layers of sediment.
• Heat and pressure from these layers helped the remains turn into crude oil.
• Crude oil exists in liquid form in underground pools or reservoirs, in tiny spaces within sedimentary rocks.
• After the oil forms, it rises from a source rock through fractures in the subsur-face due to the relatively low density of oil.
• The rising oil then migrates to a reser-voir rock, that contains tiny spaces called pores.
• The oil remains in a reservoir rock when there is an overlying cap rock through which oil cannot pass.
• The lifecycle of offshore oil and gas activities is a multi-year process consisting of various phases.
• Once production begins it may continue for several decades.
• The timing of the activities varies by region.• Mature areas like the Gulf of Mexico take relatively shorter time;
frontier areas like the Arctic could take a longer time.
Example of Activities and Timeline for a Deepwater Offshore Project
How is Oil Found?
• Hydrocarbon resources are found using exploration techniques such as seismic imaging.
• Seismic imaging assists in identifying the potential areas that may contain oil and gas.
• If an area is identified as a prospective reservoir, an exploratory well is drilled to test for the presence of hydro carbon resources.
How is Oil Produced?
• Once an oil pool is discovered, delineation wells are drilled to characterize the size of the accumulation.
• Production facilities are then fabricated and installed to extract the oil.
• Different types of facilities exist, based on water depths, to safely produce and transport the oil to shore.
Geophysical and Data Acquisition and Analysis
Lease Sale Exploratory and Development Drilling
Design, fabrication and installation
First Oil Production
BuoyAcoustic Receivers
(Streamers)Sound Wave
Source
Sound Waves
Sound Reflection Surface
Soiil Layers
Seismic SurveyVessel
What is Oil? How is it Formed?
~ 35
00 ft
~ 4 miles
YEAR 1 YEAR 11-15 YEAR 16 ONWARDSYEAR 6-10YEAR 2-5
Oil – Formation to Production
Oil
PRESSURE increases as
layer on layer of sediments deposit
As more sediments accumulate, pressure and heat builds.
Hydrocarbons begin to form eventually becoming crude oil
Sea bed
Sea bed
Oil rig
Cap rockImpermeable
Oil drawn to the
surface
Oil comes up under pressure
Sedimentary rocks
Crude oil trapped in pores in reservoir rock
Particles of mud, plant & marine animal matter
form layers of sediments
Approximately 100 Million Years Ago Present Day
