Mud pump annular friction pressure control system and method
AssigneeHydril USA Distribution LLC
InventorsDat Manh Nguyen, Ahmet Duman, Edward Walfred Eskola
Life of this patent
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Abstract
A method of controlling bottom hole pressure in a wellbore, including pumping drilling mud into the wellbore, estimating the annular friction pressure in the wellbore, and measuring the pressure of the drilling mud exiting the wellbore. The method includes measuring the flow rate of the drilling mud exiting the wellbore, and, based on the pressure of the drilling mud exiting the wellbore, the flow rate of the drilling mud exiting the wellbore, expected annular friction pressure in the wellbore, and rotational speed of drill string in the wellbore, controlling the flow rate of drilling mud exiting the wellbore to achieve a specified bottom hole pressure.
Claims20
A system for controlling bottom hole pressure in a wellbore during oil and gas drilling operations, comprising:
- a bottom hole pressure controller containing data about drilling parameters and expected annular friction pressure in the wellbore;
- a rig pump that pumps drilling mud into the wellbore via a mud supply line;
- a mud pump that controls the flow rate of the drilling mud out of the wellbore after the drilling mud circulates through the wellbore;
- a valve associated with the mud pump that has an open position for permitting drilling mud to flow through the mud pump and a closed position for preventing drilling mud from flowing through the mud pump, the valve in the open position when a pressure in the mud inlet line increases above a setpoint, and in the closed position when the pressure in the mud inlet line is below the setpoint;
- a pressure transducer in the mud inlet line that measures mud inlet line pressure data and communicates the mud inlet line pressure data to the controller;
- a flow meter in fluid communication with the mud pump that measures fluid flow rate through the mud pump and communicates fluid flow rate data to the controller;
- wherein the controller combines the mud inlet pressure data and the fluid flow rate data with the data about drilling parameters and expected annular friction pressure to determine the setpoint of the valve to control bottom hole pressure in the wellbore.
A method of controlling bottom hole pressure in a wellbore, the method comprising the steps of:
- (a) pumping drilling mud into the wellbore;
- (b) estimating the annular friction pressure in the wellbore;
- (c) measuring the pressure of the drilling mud exiting the wellbore;
- (d) measuring the flow rate of the drilling mud exiting the wellbore;
- (e) based on the pressure of the drilling mud exiting the wellbore, the flow rate of the drilling mud exiting the wellbore, expected annular friction pressure in the wellbore, and rotational speed of drill string in the wellbore, controlling the flow rate of drilling mud exiting the wellbore to achieve a specified bottom hole pressure by opening a valve when a pressure in the mud inlet line increases above a setpoint, and closing the valve when the pressure in the mud inlet is below the setpoint.
A method of controlling bottom hole pressure in a wellbore, the method comprising the steps of:
- (a) pumping drilling mud into a wellbore with a rig pump;
- (b) pumping drilling mud, after circulation through the wellbore, from the wellbore to a rig with a mud pump, the mud pump having a mud inlet line, a mud outlet line, a water supply line, and a water discharge line;
- (c) attaching a pressure transducer to the mud inlet line to determine the pressure of the drilling mud exiting the wellbore;
- (d) attaching a flow meter to the water discharge line to measure the flow rate of drilling mud through the mud pump;
- (e) combining data from the pressure transducer, data from the flow meter, expected annular friction pressure in the wellbore, and rotational speed of drill string in the wellbore, to calculate a desired flow rate of drilling mud from the wellbore to achieve a desired down hole pressure;
- (f) adjusting a valve associated with the mud pump to control the flow rate of drilling mud from the wellbore.
Dependencies are inferred from the claim text.