Radial density information from a betatron density sonde
AssigneeSchlumberger Technology Corporation
InventorCharles R. Case
Life of this patent
Estimating the term…
Abstract
An apparatus and a method for determining characteristics of earth formations traversed by a borehole that compensates the mudcake and standoff effects with fewer than usual detectors. The apparatus includes an radiation source effective to generate first and, spatially as well as temporally separate, second X-rays for irradiating earth formations from first and second entrance angles, one or more X-ray detectors capable of generating a first and a second signal indicative of the intensity of the first and second X-rays returned from earth formations to the detectors and a housing accommodating the radiation source and the detectors.
Claims18
An apparatus for determining characteristics of earth formations surrounding a borehole, the apparatus comprising:
- a radiation source effective to generate a first and a temporally and spatially different second X-ray source, the first and second X-ray sources irradiating earth formations from temporally and spatially different first and second entrance angles;
- one or more X-ray detectors capable of generating a first and a second signal indicative of the intensity of the first and second X-ray sources returned from earth formations to the one or more X-ray detectors;
- and
- a housing accommodating the radiation source and the one or more X-ray detectors.
A method of determining characteristics of earth formations surrounding a borehole, comprising the steps of:
- a) providing a radiation source, the radiation source effective to generate a first and a temporally and spatially different second X-ray source;
- b) irradiating earth formations with the first and the second X-ray sources from spatially differently first and second entrance angles;
- c) detecting the first and the second X-rays scattered from earth formations;
- d) generating a first and a second signal indicative of the intensity of the detected first and second X-ray sources;
- and
- e) calculating a formation density from the first and the second signals.
A device for determining characteristics of earth formations in a subterranean environment, the device comprising:
- a radiation source effective to generate two or more X-ray sources, the two or more generated X-ray sources each irradiating earth formations at different times and at different entrance angles;
- and
- one or more X-ray detectors capable of generating a first and a second signal indicative of the intensity of a first and a second X-ray source from the two or more X-ray sources returned from earth formations to the one or more X-ray detectors.
A method of determining characteristics of earth formations surrounding a borehole, comprising the steps of:
- a) lowering a sonde into an oil well borehole, said sonde comprising:
- an energy source effective to generate a first and a spatially different second X-ray,
- one or more X-ray detectors, and
- a housing, said housing accommodating said energy source and said detectors;
- b) irradiating earth formations with said first and said second X-rays from spatially differently first and second entrance angles;
- c) detecting said first and second X-rays scattered from earth formations;
- d) generating a first and a second signal indicative of the intensity of said detected first and second X-rays;
- e) transmitting said first and second signals to a surface signal processing unit;
- and
- f) calculating a formation density from said first and second signals at said surface signal processing unit.
A system for determining characteristics of earth formations surrounding a borehole, said system comprising:
- a sonde adapted to be moved through a borehole, said sonde comprising:
- an energy source effective to generate a first and a spatially different second X-ray, said first and second X-rays irradiating earth formations from spatially different first and second entrance angles;
- one or more X-ray detectors, said detectors being capable of generating a first and
- a second signal indicative of the intensity of said first and second X-rays returned from earth formations to said detectors;
- and
- a housing, said housing accommodating said energy source and said detectors;
- a surface signal processing unit for calculating earth formation density from said first and second signals;
- and
- a logging cable coupled to said sonde and said surface signal processing unit, said cable
- effective to transmit said first and second signals from said sonde to said signal processing unit.
Dependencies are inferred from the claim text.