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basis of design of any production and to passage through

Inversion point separation system. The degree of drill- electric submersible of crude at 50°C ing mud contamination, especially if it pumps, hydraulic 200 is oil-based mud, is very important to submersible pumps, 170 sec-1 know. gas lift, and wellhead

Pipelines 150 340 sec-1

Both live downhole and stabilized choke valves.

510 sec-1 oil samples need to be collected and Calculation of repre- 100 analyzed. The dynamic viscosity of sentative fow regime 1020 sec-1 the oil and its water-in-oil emulsion is and shear conditions one of the more important parameters for an emulsion cre- 50 required. It defnes the factor between ation in the labora-

Temperature (°C) dry oil and emulsion viscosity for tory is recommended. 0 a system and is a key fow assur- Otherwise, the mea- 0 20 25 30 35 40 45 5055 60 ance parameter input for any system sured properties used

Water cuts (%) design. for design purposes

Figure1. An example of emulsion inversion point,

It crucial that representative fuid will be misleading, emulsion viscosity (cP) versus water cut at 50°C. samples are collected, and that the resulting in unnec- laboratory test methods selected to essary production defne the rheological properties and equipment redesign and upgrades at a

Heavy and extra heavy oils can to characterize the production chem- later date.

exhibit unusual rheological prop- istry issues are ft for purpose for each Following laboratory measurement erties and variable fow assurance system. of rheological properties, it is then characteristics during production and

An example of this would be the possible to model live fuid viscosi- processing, which must be properly measurement of fuid dynamic viscos- ties using PVT software and viscosity defned. These include, but are not ity, where the test shear conditions correlations, including algorithms, to limited to, the following, all of which must directly relate to the passage calculate relative viscosity and the must be considered in any new facil- of live fuids through the points of ratio of emulsion viscosity to stabilized ity design: n signifcant shearing, i.e. shearing due crude oil viscosity. Variable, multiphase fow and

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