Abstract: Techniques for identifying drill cuttings include drilling a wellbore; during the drilling, circulating a drilling fluid that includes a plurality of tracer pills, where each tracer pill includes a shell or coating formed of a thermoresponsive material and a tracer material enclosed within the shell; during the drilling, removing cuttings such that the cuttings become entrained within the drilling fluid; attaching the tracer material of the tracer pills to the cuttings entrained within the drilling fluid by releasing the tracer material from the shells; and circulating the drilling fluid including the cuttings with the attached tracer material through the wellbore and uphole toward a terranean surface.

Abstract: The disclosure relates to catalysts that include a fibrous silica support and a plurality of metal oxide nanoparticles including iron oxide and nickel oxide, and methods of making and using such catalysts. The fibrous silica support is a particle with radially extending fibers. The catalyst can used to convert methane into hydrogen gas. The catalysts can be introduced into an underground formation, such as with a fracking fluid, for in-situ methane conversion.

Abstract: Degradable polymer additives are provided. The degradable polymer additives include a tracer functional group that is bonded to a base polymeric component by a hydrolysable covalent bond. The base polymeric component is a polysaccharide. The tracer functional group is selected from the group comprising a halogen-containing functional group, a substituted heterocyclic aromatic group, and combination thereof. A method utilizing the degradable polymeric additives in an altered drilling fluid is provided. Such a method includes introducing the altered drilling fluid into a wellbore and recovering an associated wellbore cutting from a depleted drilling fluid.

Abstract: A method of surface logging a well includes adding each of multiple polymeric taggants to a circulating drilling fluid in an addition sequence while drilling the well. Each polymeric taggant includes a polymer and a respective fluorescent dye having an emission wavelength or excitation wavelength different from that of each other fluorescent dye. The method includes taking a sample of drill cuttings carried by a drilling fluid while drilling a well, wherein the sample of drill cuttings includes polymeric taggants attached to the drill cuttings. The method includes extracting the dyes from the sample of drill cuttings into an extract solution; determining an indication of the type of and the concentration of each of the dyes in the extract solution; and determining a depth associated with the sample of drill cuttings based on the indication of the concentration of each of the dyes and on the addition sequence.

Abstract: A method of surface logging a well includes adding each of multiple polymeric taggants to a circulating drilling fluid in an addition sequence while drilling the well. Each polymeric taggant includes a polymer and a respective fluorescent dye having an emission wavelength or excitation wavelength different from that of each other fluorescent dye. The method includes taking a sample of drill cuttings carried by a drilling fluid while drilling a well, wherein the sample of drill cuttings includes polymeric taggants attached to the drill cuttings. The method includes extracting the dyes from the sample of drill cuttings into an extract solution; determining an indication of the type of and the concentration of each of the dyes in the extract solution; and determining a depth associated with the sample of drill cuttings based on the indication of the concentration of each of the dyes and on the addition sequence.

Abstract: Degradable polymer additives are provided. The degradable polymer additives include a tracer functional group that is bonded to a base polymeric component by a hydrolysable covalent bond. The base polymeric component is a polysaccharide. The tracer functional group is selected from the group comprising a halogen-containing functional group, a substituted heterocyclic aromatic group, and combination thereof. A method utilizing the degradable polymeric additives in an altered drilling fluid is provided. Such a method includes introducing the altered drilling fluid into a wellbore and recovering an associated wellbore cutting from a depleted drilling fluid.