High percentage water content monitor

A monitor which is capable of measuring accurately the water content in percent by volume of an oil and brine mixture, where the water content is 80% or more, includes a housing which is adapted to be connected to a pipe through which the oil and brine mixture is flowing so that the oil and brine mixture flows through a portion of the housing. A sensor is mounted within the housing so that the sensor is suspended in the flowing oil and brine mixture. The sensor provides a signal corresponding to the percent by volume of water in the oil and brine mixture, even when percent by volume of water is 80% or more, in response to an excitation voltage from a source. Indicating apparatus provides an indication of the percent by volume of the water in the oil and brine mixture in accordance with the signal from the sensor.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates to monitors in general and, more 
particularly, to crude-in-brine monitors. 
SUMMARY OF THE INVENTION 
An oil-in-brine monitor capable of measuring percent by volume of water in 
an oil-in-brine mixture in which the water content is 80% or more includes 
a housing which houses a sensor. The sensor receives an excitation voltage 
from a source and provides a signal in accordance with the water content 
of the oil-in-brine mixture. Apparatus provides an indication of the 
percent water in the mixture in accordance with the signal from the 
sensor. 
The objects and advantages of the invention will appear more fully 
hereinafter, from a consideration of the detailed description which 
follows, taken together with the accompanying drawing wherein one 
embodiment is illustrated by way of example. It is to be expressly 
understood, however, that the drawing is for illustration purposes only 
and is not to be construed as defining the limits of the invention.

DESCRIPTION OF THE INVENTION 
The determination of water content in oil-in-brine mixtures is of utmost 
importance to the petroleum industry. In the conventional use of 
commercial capacitance type sensors, the devices are usually limited to 
applications where brine-in-oil emulsions are monitored. This effectively 
limits the application to a water cut of 0 to 70 percent by volume of 
water in oil. 
For oil production water flood projects, water cut values of 80% to 100% 
are common. In this water cut range, where free brine is present, the 
capacitance type probes are not applicable. The present invention utilizes 
a resistivity measuring technique for determining the water content in an 
oil-in-brine mixture where there is a water cut range of 80% to 100%. 
It should be noted where the water content of the mixture is in the 
vicinity of 74% to 76%, the water becomes the continuous phase which 
contains the oil. This type of mixture is unstable and will separate into 
water and oil in a relatively short time period. A water-in-oil mixture, 
i.e. where oil is the continuous phase, is highly stable and does not 
separate readily. 
Referring now to the FIGURE, there is shown a monitor which for resistivity 
determination of water cuts in the 80% to 100% range includes a tee 3 
having concentric reducers 6 welded to opposite ends. Concentric reducers 
6 reduce the measuring cell size down to the pipe diameter. Victaulic 
adaptors 10 are welded to the narrow ends of reducers 6. A flange 
extension 15 is welded to the remaining open end of tee 3. 
A probe assembly includes an outlet box 21 having an internal threaded end 
for being connected to a sensor extension arm 24. Sensor extension arm 24 
also has internal threads at the end that is connected to outlet box 21 
and external threads at the opposite end. A plug 28 is threaded into 
sensor extension arm 24 and has a passageway for the passage of wires. A 
probe flange 30 is welded to sensor extension arm 24 and has holes for 
mounting bolts 83 which are used to affix robe flange 30 to flange 
extension 15. A wiper 36 of neoprene rubber is held in place by a plastic 
retainer 38 which is affixed to probe flange 30 by screws 44. A thermistor 
54 is mounted in a connector 52 which is connected to extension arm 24. 
Sensor head 50 containing two toroidal coils 55 and 56, one for 
transmitting (coil 55) electromagnetic energy into the flowing 
oil-in-brine mixture and one for receiving (coil 56) the electromagnetic 
energy from the mixture. Head 50 may be of the type manufactured by Great 
Lakes Instruments, Inc. as their part number 32014 electrodeless sensor. 
The wires (not shown) from thermistor 54 and coils 55, 56 pass through 
extension arm 24 to outlet box 21 and are connected to analyzer means 63 
by way of a cable in a conduit 60. Analyzer means 63, which may be of the 
type also manufactured by Great Lakes Instruments, Inc. as their model 75 
conductivity analyzer, also provides an excitation voltage to coil 55. 
Analyzer means 63 provides an indication of the water content of the 
mixture in accordance with the signals from coil 56 and from thermistor 
54. 
The present invention as hereinbefore described is an oil-in-brine monitor 
which measures the water cut of a mixture wherein the water cut lies 
within the range of 80 to 100 percent.