Degradable tags for depth correlation mud logging
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.
1. An altered drilling mud, comprising:
a base fluid; and
a degradable polymeric additive comprises a tracer functional group that is bonded to a base polymeric component by a hydrolysable covalent bond, where the base polymeric component is a polysaccharide and where the tracer functional group is a combination of at least one halogen-containing functional group and a substituted heterocyclic aromatic group, wherein the at least one halogen-containing functional group is derived from a halogenated aromatic compound.
2. The altered drilling mud of claim 1 , where the hydrolysable covalent bond is selected from the group consisting of an ester, amide, ether, thioether, or a thioester bond.
3. The altered drilling mud of claim 1 , where the halogenated aromatic compound is selected from the group consisting of 4-fluorobenzoate, 4-chlorobenzoate, 4-bromobenzoate, and combinations thereof.
4. The altered drilling mud of claim 1 , where the polysaccharide is selected from the group consisting of starch, cellulose, dextran, xanthan gum, and combinations thereof.
5. The altered drilling mud of claim 1 , where an amount of degradable polymeric additive present in the altered drilling mud is in a range of from about 0.0001 to 5 wt. % (weight percent).
6. The altered drilling mud of claim 1 , where the altered drilling mud has a funnel viscosity in a range of from about 40 to 150 seconds.
7. The altered drilling mud of claim 1 , where the base fluid of the altered drilling mud comprises water, petroleum, or a fraction of petroleum.
8. A method of using a degradable polymeric additive, comprising:
introducing an amount of the degradable polymeric additive into a drilling fluid to form an altered drilling fluid;
introducing the altered drilling fluid into a wellbore;
recovering an associated wellbore cutting from a depleted drilling fluid; and
detecting the presence of the degradable polymeric additive associated with the associated wellbore cutting,
where the degradable polymeric additive comprises a tracer functional group that is bonded to a base polymeric component by a hydrolysable covalent bond, where the base polymeric component is a polysaccharide, and where the tracer functional group is a combination of at least one halogen-containing functional group and a substituted heterocyclic aromatic group, wherein the at least one halogen-containing functional group is derived from a halogenated aromatic compound.
9. The method of claim 8 , where the hydrolysable covalent bond is selected from the group consisting of an ester, amide, ether, thioether, or a thioester bond.
10. The method of claim 8 , where the polysaccharide is selected from the group consisting of starch, cellulose, dextran, xanthan gum, and combinations thereof.
11. The method of claim 8 , further comprising detecting the presence of the degradable polymer additive in the depleted drilling fluid.
12. The method of claim 8 , further comprising treating the depleted drilling fluid to degrade any remaining degradable polymer additive in the depleted drilling fluid.