Flow characteristic measuring apparatus and method

A differential pressure flow rate measurement apparatus comprising:

• a conduit having a flow passage for conveying a fluid flow of at least two phases, said conduit being adapted for connection to a downhole fluid flow line having a bore of predetermined transverse cross-sectional area;
• a flow energy dissipator which partially obstructs said flow passage and, in use, causes a dissipative pressure drop in the fluid, and which is capable of substantially equalising the flow velocities of the two phases;
• and
• a pressure sensor for measuring said pressure drop between at least two points along the length of the flow energy dissipator,
• wherein said flow passage, when viewed in the axial direction of the flow passage, projects an unobstructed transverse cross-sectional area which is at least 25% of the transverse cross-sectional area of said bore.

A downhole piping arrangement of a hydrocarbon well, the piping arrangement having:

• a first pipe section with a first bore,
• a second pipe section with a second bore which has a transverse cross-sectional area which is equal to or smaller than that of the first bore, and
• a differential pressure flow rate measurement apparatus connected therebetween;
• wherein the differential pressure flow rate measurement apparatus comprises:
• a conduit having a flow passage which is partially obstructed by a flow energy dissipator, and
• a pressure sensor for measuring a pressure drop caused by the flow energy dissipator, between at least two points along the length of the flow energy dissipator;
• the flow passage projecting an unobstructed transverse cross-sectional area, when viewed in the axial direction of the flow passage, of at least 25% of the transverse cross-sectional area of the second bore.

A differential pressure flow rate measurement apparatus comprising:

• a conduit having a flow passage for conveying a fluid flow, said conduit being adapted for connection to a fluid flow line having a bore of predetermined transverse cross-sectional area;
• a flow energy dissipator which partially obstructs said flow passage and which is capable of imparting an angular velocity to the fluid flow and thereby causing a dissipative pressure drop in the fluid;
• a pressure sensor for measuring said pressure drop between at least two points along the length of the flow energy dissipator;
• and
• a processor for converting the pressure drop measured by the pressure sensor into a flow rate,
• wherein said flow passage, when viewed in the axial direction of the flow passage, projects an unobstructed transverse cross-sectional area which is at least 25% of the transverse cross-sectional area of said bore.

A differential pressure flow rate measurement apparatus comprising:

• a conduit having a flow passage for conveying a fluid flow of at least two phases, said conduit being adapted for connection to a fluid flow line having a bore of predetermined transverse cross-sectional area;
• a flow energy dissipator which partially obstructs said flow passage and, in use, causes a dissipative pressure drop in the fluid, and which is capable of substantially equalising the flow velocities of the two phases;
• a pressure sensor for measuring said pressure drop between at least two points along the length of the flow energy dissipator;
• and
• a processor for converting the pressure drop measured by the pressure sensor into a flow rate,
• wherein said flow passage, when viewed in the axial direction of the flow passage, projects an unobstructed transverse cross-sectional area which is at least 25% of the transverse cross-sectional area of said bore.