Schlumberger Technology Corporation

Kenneth E Stephenson

Rogerio Tadeu Ramos

Oliver Clinton Mullins

Xu Wu

Elizabeth B Dussan V

Arthur J Becker

Richard W Gaylor

Bernard Elie Theron

Joseph Steven Pietras, Iii

Gas flow rate measurement

Single point optical probes for measuring three-phase characteristics of fluid flow in a hydrocarbon well and methods of processing signals generated by the probe are disclosed. A single fiber optic probe is coupled to a light source and apparatus for detecting reflectance and fluorescence. Light is delivered to the tip of the probe where it exits the probe and illuminates the liquid ambient the probe tip or is internally reflected in the probe when gas is located at the probe tip. If the fluid at the probe tip is oil, the light exits the probe, illuminates the oil, and causes the oil to fluoresce. According to one signal processing method of the invention, the reflectance signal is binarized at a threshold to provide a gas/liquid quasi-binary signal which changes over time. A time fraction of the signal values is used to calculate the gas holdup. According to other signal processing methods of the invention, the fluorescence indication signal is processed by taking its derivative (and if desired a second derivative) to determine the 'corners' of the fluorescence signal over time. The derivative signal exhibits a positive and a negative peak which are separated by time. The time between the peaks is used to calculate oil holdup and the amplitude of one of the peaks is used to calculate the velocity of the oil drop.

Methods and apparatus utilizing a derivative of a fluorescene signal for

Single point optical probes for measuring three-phase characteristics of fluid flow in a hydrocarbon well and methods of processing signals generated by the probe are disclosed. A single fiber optic probe is coupled to a light source and apparatus for detecting reflectance and fluorescence. Light is delivered to the tip of the probe where it either exits the probe and illuminates the liquid ambient the probe tip or is internally reflected in the probe when gas is present at the probe tip. If the fluid at the probe tip is oil, the light exits the probe, illuminates the oil, and causes the oil to fluoresce. Signal processing methods for determining holdup are disclosed. According the invention, a method for determining continuous phase velocities includes injecting a fluorescent dye into the fluid at a measured distance upstream of a probe. The time between injection and detection of the dye is used to calculate average continuous phase velocity. A water soluble dye is used to detect the velocity of water, and an oil soluble dye is used to detect the velocity of oil.

Apparatus and tool using tracers and singles point optical probes for

An x-ray generator provides a continuous bremsstrahlung photon spectrum for determining the water to liquid ratio in a mixture of oil/water/gas flowing through a pipe located a distance from the generator. A plurality of detectors measure photons passing along a beam path from the generator through the fluid. A detector is also provided to monitor the energy distribution of the generator. A time interval for measuring the output of each detector is established such that small changes in the gas to liquid ratio occur during this interval. An energy bin width is selected to provide a linear approximation of the water to liquid ratio. After binning the counts for each detector, a multi-phase flow characteristic such as the water to liquid fraction, liquid density, or liquid fraction along the beam path is determined.

X-ray water fraction meter

An x-ray generator including a light source; a high temperature photocathode arranged so as to be illuminated by light from the light source; an accelerator for accelerating electrons emitted by the photocathode; and a target onto which accelerated electrons impinge so as to produce x-rays, the target being held at substantially ground potential. The accelerator is arranged so that the photocathode is at a low voltage end of a voltage multiplier, typically held at about -100 kV, and the target is at the high voltage end at ground potential. The voltage multiplier can include a bank of nested tubular capacitor members which surround the photocathode and accelerator section and are arranged such that the outer surface is at ground potential, the same as the target.

Growing community of inventors

Cambridge, United Kingdom

Kenneth E Stephenson