Production
Oil is found in underground pockets where oil is trapped in the pores of rocks. Once a drill site has started drilling onshore or offshore a process happens where the oil is taken from the reservoir to be transported to a refinery. This process of getting the oil out of the ground is called the “production”. Oil can be extracted both on and offshore and certain machines are used to extract the oil out of the ground. There are many different oil rigs used to produce oil and gas.
Types of rigs used to produce oil:
Drill ship: Used to drill in deeper waters and can reach depths of 2500 metres. A drill ship is note held by anchors and is rather in a fixed by computer controlled thrusters. It is a mobile rig and can change location.
Jack up: A jack up rig is an immobile rig which stands on 3 or 4 legs with a max drilling depth of 150 metres of water. Although the rig itself is immobile, the platform of a jack up rig is mobile and can be raised or lowered above the ocean to avoid waves and tides. A jack up rig is able to be raised and lowered due the teeth on the legs that allow the platform to move up and down.
Fixed platform: A fixed platform is used for depths near 500 metres for long periods of time, due to its fixed position. Platforms are made of concrete and steel.
Semisubmersible: A semisubmersible rig is not a not a fixed rig and is held in place by numerous anchors around the platform. A semisubmersible rig is used for deep water like that of the drill ship.
Steps in the production of oil and gas:
Initial recovery: When a production well is first introduced, oil will initially gush out of the reservoir into the well at a fast rate because of the high pressure of the reservoir and because of the low pressure of the well. The high pressure of the reservoir is due to the rocks and sand above it, and because the water underneath it. The oil and gas will continue to move into the well until the pressure decreases to a level where it will no longer continue to rise of the well at a fast rate. This then leads to secondary recovery.
Secondary recovery: For the oil to continue to travel up the production well the pressure of the reservoir must be high enough to get the oil to move up the lower pressured well. To keep the reservoirs pressure high the method Gas injection is used to supplement the reservoirs pressure. Another technique water injection is used to maintain the high pressure of the reservoir but it’s not as effective as gas injection. Water injection is used though because it is environmentally friendly.
Things that stop the production of oil and gas:
. Weather
. Corrosion
. Maintenance downtime
Types of rigs used to produce oil:
Drill ship: Used to drill in deeper waters and can reach depths of 2500 metres. A drill ship is note held by anchors and is rather in a fixed by computer controlled thrusters. It is a mobile rig and can change location.
Jack up: A jack up rig is an immobile rig which stands on 3 or 4 legs with a max drilling depth of 150 metres of water. Although the rig itself is immobile, the platform of a jack up rig is mobile and can be raised or lowered above the ocean to avoid waves and tides. A jack up rig is able to be raised and lowered due the teeth on the legs that allow the platform to move up and down.
Fixed platform: A fixed platform is used for depths near 500 metres for long periods of time, due to its fixed position. Platforms are made of concrete and steel.
Semisubmersible: A semisubmersible rig is not a not a fixed rig and is held in place by numerous anchors around the platform. A semisubmersible rig is used for deep water like that of the drill ship.
Steps in the production of oil and gas:
Initial recovery: When a production well is first introduced, oil will initially gush out of the reservoir into the well at a fast rate because of the high pressure of the reservoir and because of the low pressure of the well. The high pressure of the reservoir is due to the rocks and sand above it, and because the water underneath it. The oil and gas will continue to move into the well until the pressure decreases to a level where it will no longer continue to rise of the well at a fast rate. This then leads to secondary recovery.
Secondary recovery: For the oil to continue to travel up the production well the pressure of the reservoir must be high enough to get the oil to move up the lower pressured well. To keep the reservoirs pressure high the method Gas injection is used to supplement the reservoirs pressure. Another technique water injection is used to maintain the high pressure of the reservoir but it’s not as effective as gas injection. Water injection is used though because it is environmentally friendly.
Things that stop the production of oil and gas:
. Weather
. Corrosion
. Maintenance downtime