Flow regime determination and flow measurement in multiphase flow pipelines

An apparatus for identifying a predetermined flow anomaly in a pipe comprising:

• an analysis pipe section;
• a first pair of pressure measuring points provided in said analysis section and including a primary upstream measuring point and a primary downstream measuring point separated by a primary pipe distance;
• a first differential pressure transducer coupled to said first pair of pressure measuring points;
• a second pair of pressure measuring points provided in said analysis section and including a secondary upstream measuring point and a secondary downstream measuring point separated by a secondary pipe distance;
• a second differential pressure transducer coupled to said second pair of pressure measuring points;
• and
• a differential pressure output port coupled to said first and second differential pressure transducers and operative to produce an output from which a primary drop in said first differential pressure, a secondary pressure drop in said second differential pressure, and a time delay between initiation of said primary pressure drop and initiation of said secondary pressure drop are identifiable so as to enable determination of the presence of said predetermined flow anomaly.

A method of identifying a predetermined multiphase flow anomaly in a pipe comprising the steps of:

• identifying an analysis pipe section, said analysis pipe section containing a multiphase fluid flow;
• measuring a first differential pressure over time at a first pair of pressure measuring points positioned along said analysis pipe section, said first pair of pressure measuring points including a primary upstream measuring point and a primary downstream measuring point separated by a primary pipe distance;
• measuring a second differential pressure over time at a second pair of pressure measuring points positioned along said analysis pipe section, said second pair of pressure measuring points including a secondary upstream measuring point and a secondary downstream measuring point separated by a secondary pipe distance;
• determining whether regular amplitude variations exist in said first pressure measurement over time and said second pressure measurement over time;
• determining whether said existent regular amplitude variations include at least a first regular amplitude variation in said first pressure measurement having an absolute magnitude greater than a first minimum pressure differential;
• determining whether said existent regular amplitude variations include at least a second regular amplitude variation in said second pressure measurement having an absolute magnitude greater than a second minimum pressure differential;
• identifying a primary starting point of said first regular amplitude variation;
• identifying a secondary starting point of said second regular amplitude variation;
• and
• determining the nature of a predetermined multiphase flow anomaly moving through the pipe analysis section as a function of a time difference between said secondary starting point and said primary starting point.