Surface located isotope tracer injection apparatus
AssigneeProtechnics International, Inc.
InventorsLawrence Taylor, III, John W. Chisholm, Philip T. Thayer
Life of this patent
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Abstract
The present disclosure is directed to a method and apparatus for controllably injection a radioactive isotope tracer fluid into a fracture fluid, a manifold or mud flow line connected to a well. It is best used in measuring well stimulation procedures based on injection of tracer isotopes so that stimulation performance data can be obtained by gamma ray spectroscopic measuring instruments lowered in the well borehole after fracture. The present apparatus utilizes a tank supply of tracer fluid connected through a pump into the mud line wherein the pump drives a tachometer, and utilizes a CPU to respond to pumping rate measurements and adjust the pumped rate of the tracer fluid.
Claims13
A method of controlling the flow of radioactive isotope tracers for injection into a well borehole comprising the steps of:
- (a) providing a flow of treatment fluid at the surface wherein the fluid flow has desired characteristics and flow rate;
- (b) injecting the fluid flow into a well at a controlled rate and pressure for formation treatment;
- (c) adding a flow of fluid mixed with a radioactive isotope at the surface to the treatment fluid;
- (d) prior to the entry of the treatment fluid flow into the well, measuring radioactivity of the treatment fluid resulting from the added radioactive isotope;
- and
- (e) dependent on the measured radioactivity, changing the relative proportion of treatment fluid flow and fluid carried radioactive isotope to obtain a desired level of radioactivity in relation to the treatment fluid flow.
The method of claim whereing the step of adding a fluid carrying an isotope therein includes:
- (a) providing a supply of radioactive isotope carrying fluid in a container;
- (b) pumping the fluid from the container;
- (c) measuring the pumping rate;
- (d) delivering the pumped flow into the flow of fluid;
- and
- (e) adjusting the rate of pumping to thereby obtain a specified proportion of fluid and fluid carried isotope.
An apparatus for use with a system for delivery of a pumped fluid into a well from the well head, the apparatus comprising:
- (a) first pump means for delivery of a flow of fluid and connected to a mud line connecting into a well for delivery of the fluid to the well;
- (b) means for measuring the rate of flow of the fluid flow delivered into the mud line for the well from the first pump means;
- (c) second pump means connected with a source of radioactive isotope tracer fluid wherein said second pump means has an output line connected with the mud line for delivery of the radioactive isotope tracer fluid into the fluid flow pumped by said first pump means;
- (d) measuring means cooperative with the mud line for measuring the rate of flow of fluid into the well whereupon the rate of flow of radioactive isotope tracer is also measured;
- and
- (e) control means connected with said measuring means for controlling the rate of pumping of the radioactive isotope tracer fluid from said second pump means so that a specified flow rate thereof is obtained.
Dependencies are inferred from the claim text.