Covalent organic frameworks as tracers for fluorescent upstream imaging
This disclosure relates to methods of charactering and analyzing drill cuttings, such as drill cuttings labeled with fluorescent covalent organic framework tracers.
1. A method of well logging, the method comprising:
adding a fluorescent covalent organic framework (COF) tracer to the well while drilling the well;
injecting the fluorescent COF tracer into drill cuttings produced while drilling the well, thereby labeling the drill cuttings with the fluorescent COF tracer;
pumping the labeled drill cuttings upwards in the well towards an annulus of the well;
collecting the labeled drill cuttings; and
identifying the fluorescent COF tracer in the drill cuttings.
2. The method of claim 1 , wherein the fluorescent COF tracer comprises fluorescent building blocks, covalently attached fluorescent moieties, fluorophores loaded into the channels and pores of the COF, or a combination thereof.
3. The method of claim 1 , wherein the fluorescent COF tracer is added to the well via a drill string of the well.
4. The method of claim 1 , wherein the fluorescent COF tracer is injected into the produced drill cuttings by breaking a capsule comprising the fluorescent COF tracer.
5. The method of claim 1 , wherein more than one fluorescent COF tracer is added to the well, and wherein each fluorescent COF tracer has a different fluorescent emission wavelength and fluorescent emission spectra.
6. The method of claim 1 , wherein the labeled drill cuttings are comprised in a drilling mud.
7. The method of claim 6 , wherein the drilling mud is pumped upwards by hydraulic circulation.
8. The method of claim 6 , further comprising separating the labeled drill cuttings from the drilling mud after collecting the labeled drill cuttings.
9. The method of claim 1 , wherein the labeled drill cuttings are collected at a shale shaker.
10. The method of claim 1 , wherein the fluorescent COF tracer in the drill cuttings is identified by ultraviolet (UV) light and a camera.
11. The method of claim 1 , further comprising determining a depth associated with the labeled drill cuttings based on the identification of the fluorescent COF tracer.
12. The method of claim 1 , wherein the well is an oil well.
13. A method of determining the depth of drill cuttings in a well, the method comprising:
obtaining drill cuttings from the well, wherein the drill cuttings are labeled with a fluorescent covalent organic framework (COF) tracer; and
identifying the fluorescent COF tracer in the drill cuttings by ultraviolet (UV) light and a camera, wherein the fluorescent COF tracer has a fluorescent emission wavelength and fluorescent emission spectra that allows for determination of the depth associated with the labeled drill cuttings.
14. The method of claim 13 , wherein more than one fluorescent COF tracer is added to the well, and wherein each fluorescent COF tracer has a different fluorescent emission wavelength and fluorescent emission spectra.
15. The method of claim 13 , wherein the drill cuttings are labeled with the fluorescent COF tracer downhole while drilling the well.
16. The method of claim 15 , wherein the fluorescent COF tracer is injected into the drill cuttings by breaking a capsule comprising the fluorescent COF tracer.
17. The method of claim 13 , wherein the identifying occurs onsite at the well.