Fluid property sensors and associated methods of calibrating sensors in a subterranean well

A method of sensing properties of fluid flowing in a subterranean well, the method comprising the steps of:

• positioning a tubing string in the well, thereby forming an annulus between the tubing string and a wellbore of the well, the tubing string including multiple ports providing fluid communication between the annulus and an interior flow passage of the tubing string;
• isolating portions of the annulus from each other, each annulus portion being in communication with a corresponding one of multiple zones intersected by the well, and each annulus portion being in communication with a corresponding one of the tubing string ports;
• and
• sensing multiple properties of fluid flowing into each of the ports utilizing multiple sensor systems interconnected in the tubing string, each sensor system being interconnected in the tubing string downstream of a corresponding one of the ports, and each sensor system including a fluid density sensor, a flowmeter, a temperature sensor, a pressure sensor and a selected one of a fluid dielectric sensor and a fluid conductivity sensor.

A method of calibrating multiple sensor systems interconnected in multiple branch tubing strings, each of the tubing strings including multiple flow control devices, each flow control device regulating fluid flow into one of the tubing strings and being positioned upstream of a corresponding one of the sensor systems relative to fluid flow in the corresponding one of the tubing strings, the method comprising the steps of:

• closing all flow control devices in all tubing strings other than a first one of the tubing strings;
• and
• with only a lowermost one of the flow control devices in the first tubing string being open, and then with successively next lowermost ones of the flow control devices in the first tubing string being opened, performing the following procedure for the open lowermost flow control device, and again performing the procedure after each successively next lowermost flow control device is opened:
• a) flowing fluid through the open one or more flow control devices into the first tubing string;
• b) measuring at the earth's surface at least one property of fluid flowing from the first tubing string;
• c) recording measurements received from sensors of the one or more sensor systems corresponding to the one or more open flow control devices;
• and
• d) determining calibration values for the measurements received from the sensors of the one or more sensor systems corresponding to the one or more open flow control devices.

A method of measuring fluid properties of fluid flowing in a subterranean well, the method comprising the steps of:

• positioning a tubing string in the well, thereby forming an annulus between the tubing string and a wellbore of the well, the tubing string including multiple ports providing fluid communication between the annulus and an interior flow passage of the tubing string;
• isolating portions of the annulus from each other, each annulus portion being in communication with a corresponding one of multiple zones intersected by the well, and each annulus portion being in communication with a corresponding one of the tubing string ports;
• sensing at least one property of fluid flowing between each corresponding zone and tubing string port;
• and
• calibrating the sensors by measuring properties of the fluid produced at the surface with at least one of the ports closed.