Borehole influx detector and method
First Claim
1. An apparatus for detecting the influx of formation fluids into a borehole and capable of being used in a drill string during a drilling operation, comprising:
- a housing capable of being coupled in a drill string;
a radiation source means mounted on said housing;
a radiation detection means spaced from said radiation source means on said housing, said detection means for detecting radiation from said source means which has substantially only passed through the fluids in said borehole.
4 Assignments
0 Petitions
Accused Products
Abstract
A system for detecting changes in drilling fluid density downhole during a drilling operation includes a radiation source and detector which are arranged in the outer wall of a drill string sub to measure the density of drilling fluids passing between the source and detector. Radiation counts detected downhole are transmitted to the surface by telemetry methods or recorded downhole, where such counts are analyzed to determine the occurrence of fluid influx into the drilling fluid from earth formations. Changes in the density of the mud downhole may indicate the influx of formation fluids into the borehole. Such changes in influx are determinative of formation parameters including surpressures which may lead to the encountering of gas kicks in the borehole. Gas kicks may potentially result in blowouts, which of course are to be avoided if possible. Hydrocarbon shows may also be indicative of producible formation fluids. The radiation source and detector in one embodiment of the system are arranged in the wall of the drill string sub to provide a direct in-line transmission of gamma rays through the drilling fluid.
86 Citations
31 Claims
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1. An apparatus for detecting the influx of formation fluids into a borehole and capable of being used in a drill string during a drilling operation, comprising:
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a housing capable of being coupled in a drill string; a radiation source means mounted on said housing; a radiation detection means spaced from said radiation source means on said housing, said detection means for detecting radiation from said source means which has substantially only passed through the fluids in said borehole. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A borehole logging apparatus mounted in a drill string for use in a drilling operation, including:
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a housing arranged for coupling in a string of pipe and having a central passageway therein for permitting the passage of a drilling fluid therethrough; recess means on the external wall of said housing in the flow path of drilling fluids passing along said housing; the wall thickness of said housing transversely adjacent said recess means being sufficient to maintain the structural integrity of said housing in said drill string; and means mounted in said recess means for detecting the density of drilling fluids passing along said housing by detecting radiation which has substantially only passed through said drilling fluids from a radiation source on said housing. - View Dependent Claims (12, 13)
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14. A method for determining density of a drilling fluid during a drilling operation including the steps of:
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positioning an annular housing in a drill string which housing includes a density measuring device comprising a radiation source and a radiation detector spaced therefrom; running the density measuring device into the borehole on the drill string; measuring the density of the drilling fluids in the drilling annulus at a downhole location by detecting with said radiation detector radiation from said radiation source which has substantially only passed through said drilling fluids; and telemetering data to the surface indicative of the density of downhole fluids. - View Dependent Claims (15, 16, 17)
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18. A method for detecting during drilling, the influx of formation fluids into a borehole being drilled by a drill bit operating on a drill string and utilizing a drilling fluid passing through the drill string and up the borehole annulus to the surface, including the steps of:
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positioning at least one radiation source and detector in a housing and incorporating such housing in a drill string; running the housing into the borehole on the drill string; counting that radiation which passes from the source to the detector through the borehole fluids when such source and detector are immersed in borehole fluids; and detecting changes in the radiation count to determine the influx of formation fluids into the borehole. - View Dependent Claims (19, 20, 21)
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22. Apparatus for measuring changes in the density of a drilling fluid during a drilling operation, including:
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housing means arranged for mounting in a drill string; means mounted on said housing for detecting discrete values of density of drilling fluids passing said housing at a downhole location comprising radiation source means on said housing means and radiation detection means spaced therefrom on said housing means for detecting radiation substantially passing only through said drilling fluids; means on said drill string for telemetering data signals to the surface; and means for providing data signals to said telemetering means indicative of the density of such drilling fluids. - View Dependent Claims (23, 24, 25)
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26. Apparatus for measuring the density of drilling fluids in a borehole during a drilling operation, including:
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a housing arranged for coupling in a string of pipe having a central passageway therein for passage of a drilling fluid therethrough; radiation source means mounted on the outer wall of said housing; radiation detector means mounted in the outer wall of said housing; and collimating means associated with said radiation source means and detector means for substantially directing the path of radiation between said source means and detector means only through borehole fluids. - View Dependent Claims (27, 28, 29, 30, 31)
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Specification