Measurement of moisture in crude oil with a high gas volume content

For all existing crude oil moisture meters, the metering error increases when gas appears in oil. For most of them, when gas volume content exceeds  2 - 5%, the metering error becomes unacceptable.

A solution has been found specifically for FIZEPR-SW100 series in-line moisture meters to ensure accurate crude oil moisture measurement even with a high gas volume content. The solution is shown in the figure.

This solution has become possible due to a large volume measured in the FIZEPR-SW100 sensors at a time. For example, the material volume controlled in FIZEPR-SW100.20.12 (DN80, PN63) sensors at once is more than 2 liters. Crude oil consisting of poorly mixed water and hydrocarbons is measured as a homogeneous mixture when such a large volume is analyzed.

This feature of moisture meters ensures a solution based on a sharp drop of the flow speed when the pipeline section is expanded. When the flow speed drops abruptly (the figure shows a version with a 30 times speed drop), the gas is separated: it is separated from the liquid and passes through a separate channel outside the moisture meter. It means that the crude oil flowing through the moisture meter is also stratified, but as shown above, this stratification has little effect on measurement results.

The proposed design is welded from standard pipe fittings: tees according to GOST 17376-2001 or TU 1469-001-82932963-2009 specifications, adapters according to GOST 17378-2001 and bends according to GOST 30753-2001. The total costs of the tees, adapters and bends made of 09G2S steel shown in the drawing do not exceed 68 thousand rubles.