Simulation of subsurface formations for the testing and calibration of radioactive well logging tools
AssigneeMobil Oil Corporation
InventorWyatt W. Givens
Life of this patent
Estimating the term…
Abstract
A radioactive medium simulates a desired subsurface formation condition for the testing and calibration of radioactive well logging tools. The medium simulates a state of radioactive equilibrium in which the decay products of the parent isotope decay at a desired rate to that at which they are produced within the medium.
Claims20
A method of testing a uranium assay logging tool, comprising the steps of;
- (a) providing a refined uranium bearing medium of suitable thickness to simulate the condition of the uranium content of a subsurface formation,
- (b) adding radium to said medium to achieve a desired state of apparent radioactive equilibrium between said refined uranium and its decay products lead and bismuth which emit the abundance of gamma-rays associated with a natural uranium ore,
- (c) exposing said logging tool to the radioactive radiation of the medium, and
- (d) measuring the response of said logging tool to said radioactive radiation from said medium.
A method of testing a borehole logging tool adapted to respond to the uranium content of the subsurface formations surrounding a borehole, comprising the steps of:
- (a) exposing said borehole logging tool to a uranium bearing medium of suitable thickness to simulate a subsurface condition surrounding a borehole in which a uranium parent and its decay products, lead and bismuth, are in a desired state of apparent radioactive equilibrium, and
- (b) measuring the response of said borehole logging tool to said medium.
A method of simulating the radioactivity condition of a subsurface formation surrounding a borehole, comprising the steps of:
- (a) adding refined uranium to a medium of suitable thickness to simulate the condition of a subsurface formation, and
- (b) adding radium to said medium to achieve a desired state of apparent radioactive equilibrium in which the end decay products of the parent uranium content of said medium are decaying at a desired rate relative to that at which they are being produced within said medium.
Dependencies are inferred from the claim text.