Method for analyzing a petroleum stream

Methods are provided for determining a solids to liquids ratio in a flowing petroleum stream having an immiscible solids, oil and water flow. Microwave energy in the 10-12 Gigahertz bond is directed through the petroleum stream and attenuated transmitted and reflected microwave energy are detected. The detected microwave energy is compared to an empirically derived map of attenuated amplitude vs. phase for a set of reference petroleum streams having known solid, oil and water contents to derive a solids to liquids ratio for the unknown stream.

BACKGROUND OF THE INVENTION 
FIELD OF THE INVENTION 
The present invention relates to analyzers and analyzing methods in general 
and, more particularly, to petroleum stream analyzers and analyzing 
methods. 
SUMMARY OF THE INVENTION 
The methods of the present invention include a source of microwave energy 
and associated elements which provide microwave energy to a petroleum 
stream. Other circuitry includes elements which receive transmitted and 
reflected microwave energy from the petroleum stream. Electronic analyzer 
apparatus provides at least two outputs utilizing the provided microwave 
energy, the received transmitted and reflected microwave energy and known 
values for 100 percent oil, 100 percent solids of one species and 100 
percent water, corresponding to different ratios, these ratios involving 
oil and water, oil and solids, water and solids, which, when mixed, are 
immiscible. 
The objects and advantages of the present invention will appear more fully 
hereinafter from a consideration of the detailed description which 
follows, taken together with the accompanying drawings wherein one 
embodiment of the invention is illustrated by way of example. It is to be 
expressly understood, however, that the drawings are for illustration 
purposes only and not to be construed as defining the limits of the 
invention.

DESCRIPTION OF THE INVENTION 
Extraction of oil from tar sands and/or diatomaceous earth, hereinafter 
referred to as D.E., can be accomplished by keeping the components 
stationary for example by pelletization of the D.E. and passing a solvent 
through the mixture or by flowing some combination of the mixture, water 
and solvent through a pipe from which desired or undesired components are 
extracted. However, these type of producing methods results in solids of 
tar sand or D.E. occurring in the produced petroleum stream. The present 
invention will yield the relationships water to oil, water to solids 
and/or solids to oil. 
The analyzer shown in FIG. 1 includes a microwave source 3 providing 
electromagnetic energy, hereinafter referred to as microwave energy 
preferably in the 10-12 gigahertz band. Source 3 is low powered and may 
use a microwave Gunn Diode source. Source 3 provides the microwave energy 
to a directional coupler 7. Directional coupler 7 provides the selected 
microwave energy to a circulator 8 and to a conventional type voltage 
controlled phase shifter 9. All conductance or carrying of microwave 
energy is accomplished by using conventional type waveguides. 
Circulator 8 provides microwave energy to an antenna 12. Antenna 12 
provides the microwave energy through a window 14, which may be of a low 
loss dielectric material such as ceramic or teflon, to a petroleum stream 
having these immiscible components passing through a pipe 17. Pipe 17 may 
be a portion of a pipeline having windows 14 or it may be of the "window" 
material. The microwave energy provided by antenna 12 passes through the 
petroleum stream and another window 14 and is received by an antenna 20. 
Antenna 20 provides the received microwave energy to a switch means 24 
which in turn provides the received microwave energy as test microwave 
energy to a directional coupler 28, as hereinafter explained. Directional 
coupler 28 provides the test microwave energy to a detector 32 and to a 
mixer 34. Detector 32 provides a signal E2 corresponding to the intensity 
of the microwave energy received by antenna 20. 
The petroleum stream also reflects some of the microwave energy back to 
antenna 12 which passes back through antenna 12 to circulator 8. 
Circulator 8 blocks the reflected microwave energy from feeding back to 
source 3 and provides the reflected microwave energy to switch means 24. 
Reflected microwave energy becomes more important as the distance between 
antennas 12 and 20 increases. This is especially true where a large 
diameter pipeline carrying the petroleum stream is being monitored. 
A positive direct current voltage +V is provided to a switch 36 which is 
connected to switch means 24. With switch 36 open, switch means 24 
provides received attenuated microwave energy from antenna 20 as test 
microwave energy. When switch 36 is closed, the reflected microwave energy 
from antenna 12 via circulator 8 is provided by switch means 24 as the 
test microwave energy. In either incidence the test microwave energy is 
supplied to mixer 34 via a directional coupler 28. 
The microwave energy from voltage controlled phase shifter 9, hereinafter 
called the reference microwave energy, and the test microwave energy from 
the directional coupler 28, are provided to mixer 34 which mixes them to 
provide two mixer output electrical signals E3 and E1, representative of 
the relative phases of the reference microwave energy and the test 
microwave energy, respectively. These signals are supplied to a 
differential amplifier 30. 
The differential amplifier 30 provides an output signal EO in accordance 
with the difference between signals E3 and E1. Signal EO is a function of 
the phase difference between the reference microwave energy and the test 
microwave energy and is provided to a feedback network 44. Feedback 
network 44 provides a signal C to voltage controlled phase shifter 9, 
controlling the phase of the reference microwave energy, and to a 
mini-computer means 50. Signal EO, and hence the signal C decreases in 
amplitude until there is substantially 90.degree. phase difference between 
the reference microwave energy and the test microwave energy. Voltage 
controlled phase shifter 9 indicates the amount of phase shift required to 
eliminate the phase difference between the test signal and the reference 
signal. 
Signal E2 from a detector 32 which is representative of the test signal is 
also provided as input to computer means 50. 
A temperature sensor 52 senses the temperature of the petroleum stream in 
pipe 17 and provides a signal T to the computer means 50 representative of 
the sensed temperature. 
The voltage controlled phase shifter 9 also provides an enable signal to 
computer means 50 allowing the computer means 50 to utilize signals T, C 
and E2. Under some circumstances the phase difference signals can exceed 
360.degree.. Such ambiguities can be avoided and the signal "normalized" 
to the nearest integer multiple of 360.degree. by monitoring the intensity 
of the transmitted microwave energy as described in Co-assigned U.S. Pat. 
No. 4,947,128. 
FIG. 2A is a plot or "map" of a water-continuous phase petroleum stream 
with 100% solid D.E., 100% water and 100% oil points shown as D.E., water 
and oil, respectively. FIG. 2B is a "map" of an oil-continuous phase 
petroleum stream having solid D.E. The ordinate axes of FIG. 2A and FIG. 
2B represent amplitude attenuation of the microwave energy, i.e., the 
amount transmitted through the petroleum stream. The abscissae axes of 
FIG. 2A and FIG. 2B represent the relative phase angles of a known 
petroleum stream having a variable solids/liquid and oil/water ratio. The 
maps of FIGS. 2A and 2B were developed from empirical data utilizing the 
following equations: 
1. Y.sub.L1 =f(X), where f(X) denotes y is a function of X, where X is 
equal to phase shift and y is attenuation which describes a curve L1, 
connecting 100% D.E. or solid to 100% water. 
2. Y.sub.L2 =g(X), where g(X) denotes y as another function of X and L2 is 
a curve connecting 100% oil to 100% water. 
3. Y.sub.L3 =H(X), where h(X) denotes y as yet another function of X and L3 
is a curve connecting 100% D.E. or solid to 100% oil. 
In all of the above described curves X is the phase angle as previously 
described. 
In general, the maps depicted in FIGS. 2A and 2B are utilized by computer 
means 50 as follows. The amplitude attenuation and phase shift 
measurements of the microwave energies in pipe 17 for an unknown stream to 
be measured are shown in FIGS. 2A and 2B as point P. The procedure is the 
same, whether the petroleum stream is water-continuous or it is 
oil-continuous. A curve L4, of functional form identical to curve L3, or, 
as an approximation, a straight line as shown in FIG. 2A is projected by 
computer means 50 through the 100% D.E. solids point, through point P, to 
intercept curve L2, which is in essence a water-oil curve connecting the 
100% water point and the 100% oil point, at point I. Point I, the 
intersection point of curve or line L4 and L2, yields the water cut of the 
petroleum stream by taking the ratio of the length along L2 from the 100% 
water point to the total length along L2 (from the 100% oil point to the 
100% water point). Further, the D.E. or solid to liquid ratio of the 
stream may also be determined as the ratio of the distance from point P to 
point I along curve or line L4 divided by the distance from the 100% solid 
D.E. point to point I along curve L4. If there are no solids present in 
the petroleum stream, point P would lie on curve L3 and the solid to 
liquid ratio would be zero as the distance from point P to point I along 
curve L3 would be zero. 
Although the foregoing has been discussed as being a water cut and a solid 
to liquid fraction measurement, the maps such as FIGS. 2A and 2B may also 
yield other ratios. Computer means 50 may generate curves such as L4 or 
FIG. 2B from the 100% water point to intercept curve L3. Again, that ratio 
of distance along such a curve to its total length would be determined in 
the same manner as previously discussed for the D.E. solid to liquid 
ratio. Computer means 50 may also generate curve such as a straight line 
from the 100% oil point through point P and intercept line L1. Similar 
ratios of distances or lengths along such a line could be interpreted as a 
percent of water in the petroleum stream.