The objective is to present accurately the performance of the combination of a venturi and multi energy gamma ray in a case study in Venezuela. The focus will be on practical information, knowledge sharing to overcome all classical problems due to fluid behavior met by multiphase metering device in extra heavy oil including classical separator.

Heavy and Extra-Heavy Oil represents more than 50% of the worldwide oil reserves, and large efforts have been spent to overcome difficulties related to this kind of oil production. Venezuela has pone of the largest reserve of HO and EHO with more than currently 1.5 trillion of oil in place. Different set of technologies and methodologies have been used to overcome the technical production and monitoring challenges in these lifted or pumped wells.

Petroleos de Venezuela (PDVSA) at the opposite of Canada companies is currently producing most of the Heavy Oil from cold and therefore non thermal production methods due to historical reasons. Recently, Orocual field in Monagas Northern (Venezuela) was put in production a cluster with extra heavy oil reaching gravity from 8.6 to 11 API and with a viscosity range from 6 Pa.s to more than 20 Pa.s at line conditions. As per fact, this new production cluster did not have any data, and PDVSA could only use conventional storage tanks to try to estimate the liquid flow rate with no possibility to be able to get the gas production because no separator were able to work in these conditions.

However, it was essential to PDVSA in this early phase of the development to review the performance of the field and get access to the oil, water and gas flow rates. In these challenging conditions, and after trying other multiphase meters said to work in Extra Heavy Oil, PDVSA found that the only solution was Venturi - multi energy gamma ray combination.

This multiphase technology broke the extra heavy oil paradigm related to multiphase technology to measure flow rates accurately and a comparative test were capable to demonstrate when it was possible from a reference point of view that the overall uncertainty of the entire system (Venturi-Tank) was better than 2%. This extended the new multiphase technology operating envelope for PDVSA from Gas to Extra Heavy Oil and provided a unique solution and the capability to monitor and optimize in real-time the production in this field.

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