Fluid handling system for use in drilling of wellbores

A vessel for separating materials from a wellbore fluid, comprising:

• (a) a first stage for separating solids contained in the fluid;
• (b) a pressure sensor for determining pressure in the vessel;
• (c) a second stage for separating oil and water into a separate reservoir;
• (d) a separate level sensor associated with the water reservoir and the oil reservoir for respectively determining water level and oil level in their respective reservoirs;
• and
• (e) a control circuit, said control circuit receiving signals from the pressure sensor and each of the level sensors for controlling the pressure, oil level, and water level in the vessel.

A fluid-handling system for separating constituents of a wellstream, comprising:

• (a) a first vessel having
• (i) a first stage for separating solids contained in the fluid,
• (ii) a second stage for separating oil and gas,
• (iii) a pressure sensor associated with the first vessel for determining the pressure in the first vessel, an oil level sensor for determining the level of the oil in the vessel and a water level sensor for determining the level of water in the first vessel,
• (iv) a pressure controller for automatically controlling the flow of gas from the first vessel by modulating a gas control valve to maintain the pressure in the vessel below a predetermined value;
• (v) a first level controller for automatically controlling the flow of oil from the first vessel by modulating a flow control valve as a function of the oil level in the vessel to maintain the oil level in the vessel below a predetermined level;
• (vi) a second level controller for automatically controlling the flow of water from the first vessel by modulating a second flow control valve as a function of the pressure in the vessel to maintain the water level in the vessel below a predetermined level;
• (b) a second vessel for receiving oil from the first vessel, said second vessel having a pressure controller cooperating with a pressure sensor associated with the second vessel to discharge any gas contained in the second vessel, said second vessel also having a level controller cooperating with a level sensor to maintain the oil in the second vessel below a predetermined level;
• and
• (c) a third vessel for receiving fluid that is substantially free of oil from the first vessel, said third vessel having a pressure controller cooperating with a pressure sensor associated with the third vessel to discharge any gas contained in the third vessel, said third vessel also having a level controller cooperating with a level sensor to maintain the fluid in the third vessel below a predetermined level.

A method for separating solids, oil, gas and water from a relatively high pressure wellbore fluid, comprising:

• (a) reducing the wellbore fluid pressure to a relatively low pressure;
• (b) discharging the relatively low pressure fluid into a separator and removing solids from the wellbore fluid within the separator;
• (c) controlling discharge of gas from the separator by a gas flow control device by a control unit so as to maintain the pressure in the separator below a predetermined value;
• (d) separating oil and water within the separator;
• (e) controlling discharge of oil from the separator through an oil flow device by the control unit so as to maintain the oil level in the separator below a predetermined value;
• and
• (f) controlling discharge of water from the separator through a water flow device by the control unit so as to maintain the water level in the separator below a predetermined value.

A fluid-handling system for separating constituents of a wellbore fluid that is at a relatively high pressure, comprising:

• (a) a fluid flow control device for receiving the wellbore fluid at the relatively high pressure and discharging the received fluid at a relatively low pressure;
• (b) a vessel for receiving the wellbore fluid from the fluid flow control device and for separating constituents of the wellbore fluid, said vessel having,
• (i) a first stage for separating solids contained in the fluid;
• (ii) a pressure sensor for determining pressure in the vessel;
• (iii) a second stage for separating oil and water into a separate reservoir;
• (iv) a separate level sensor associated with the water reservoir and the oil reservoir for respectively determining water level and oil level in their respective reservoirs;
• and
• (c) a control circuit, said control circuit receiving signals from the pressure sensor and each of the level sensors for controlling the pressure, oil level, and water level in the vessel.

A method for separating constituents of a relatively high pressure wellbore fluid comprising:

• (a) reducing the wellbore fluid pressure to a relatively low pressure;
• (b) discharging the relatively low pressure fluid into a separator and separating solids from the fluid in said separator;
• (c) determining pressure in the vessel;
• (d) automatically discharging gas from the separator through a gas flow control device in response to the determined pressure in the vessel so as to maintain the pressure in the separator below a predetermined value.

A fluid-handling system for separating constituents of a wellstream, comprising:

• (a) a first vessel having
• (i) a first stage for separating solids contained in the fluid,
• (ii) a second stage for separating oil and gas,
• (iii) a pressure sensor associated with the first vessel for determining the pressure in the first vessel;
• (iv) a pressure controller for automatically controlling the flow of gas from the first vessel to maintain the pressure in the vessel below a predetermined value;
• and
• (b) a second vessel for receiving oil from the first vessel, said second vessel having a pressure controller cooperating with a pressure sensor associated with the second vessel to discharge any gas contained in the second vessel, said second vessel also having a level controller cooperating with a level sensor to maintain the oil in the second vessel below a predetermined level.