TRACER COMPOSITIONS
The present disclosure relates to tracing gas flow in a hydrocarbon reservoir with compositions including a degradable polymer and a detectable component. An exemplary method includes introducing a tracer composition at a first location in the reservoir, contacting the tracer composition with the reservoir to hydrolyze the degradable polymer, and detecting a degraded tracer composition including the hydrolyzed polymer and the detectable component in a gas sample collected at a second location in the reservoir.
1 . A method of tracing gas flow in a hydrocarbon reservoir, comprising:
introducing a tracer composition at a first location in the reservoir, wherein the tracer composition comprises a degradable polymer and a detectable component;
contacting the tracer composition with the reservoir to hydrolyze the degradable polymer; and
detecting a degraded tracer composition in a gas sample collected at a second location in the reservoir, wherein the degraded tracer composition comprises the hydrolyzed polymer and the detectable component;
wherein the detectable component comprises a colorant.
2 . The method of claim 1 , wherein the degradable polymer comprises a thermoplastic.
3 . The method of claim 2 , wherein the thermoplastic comprises a poly (lactic acid).
4 . The method of claim 1 , wherein the degradable polymer comprises a thermoplastic polyester elastomer.
5 . The method of claim 4 , wherein the thermoplastic polyester elastomer comprises a block copolymer comprising a hard segment and a soft segment.
6 . The method of claim 5 , wherein the hard segment comprises a polyester comprising an alkylene diol monomer unit and an aromatic dicarboxylic acid monomer unit.
7 . The method of claim 6 , wherein the alkylene diol monomer unit comprises ethylene glycol, propylene diol, butylene diol, or any combination thereof.
8 . The method of claim 6 , wherein the aromatic dicarboxylic acid monomer unit comprises terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, or any combination thereof.
9 . The method of claim 6 , wherein the hard segment comprises ethylene terephthalate, propylene terephthalate, butylene terephthalate, or any combination thereof.
10 . The method of claim 5 , wherein the soft segment comprises a polyether, a polyester, a polycarbonate, or any combination thereof.
11 . The method of claim 10 , wherein the soft segment comprises a polyether, and the polyether comprises a polyoxyalkylene glycol.
12 . The method of claim 11 , wherein the polyoxyalkylene glycol comprises polytetramethylene glycol.
13 . The method of claim 1 , wherein the colorant is detectable in the visible spectrum.
14 . The method of claim 13 , wherein the colorant comprises a pigment.
15 . The method of claim 14 , wherein the colorant comprises a green pigment, a red pigment, or a yellow pigment.
16 . The method of claim 1 , wherein the tracer composition comprises an extrudate of the degradable polymer and the detectable component.
17 . The method of claim 1 , wherein the tracer composition comprises particles having an average size of at least about 5 mm.
18 . The method of claim 17 , wherein the particles of the tracer composition comprise pellets or fibers.
19 . The method of claim 18 , wherein the particles comprise fibers having an average length of at least about 4 mm.
20 . The method of claim 17 , wherein the degraded tracer composition comprises particles having an average size of less than about 2 mm.
21 . The method of claim 20 , wherein the particles of the degraded tracer composition comprise a powder.
22 . The method of claim 1 , wherein introducing the tracer composition comprises pumping a stimulation fluid comprising the tracer composition into the reservoir at the first location.
23 . The method of claim 22 , wherein the stimulation fluid comprises an acid.
24 . The method of claim 1 , wherein the second location comprises a gas pipeline.
25 . The method of claim 1 , wherein detecting the degraded tracer composition comprises capturing the degraded tracer composition on a filter.
26 . The method of claim 1 , wherein detecting the degraded tracer composition comprises visualizing the colorant.
27 . A stimulation fluid comprising an aqueous medium and a tracer composition, wherein
the tracer composition is suspended in the aqueous medium; and
the tracer composition comprises a degradable polymer and a detectable component, wherein the detectable component comprises a colorant.
28 . The stimulation fluid of claim 27 , further comprising an acid.
29 . The stimulation fluid of claim 28 , wherein the acid comprises hydrofluoric acid, hydrochloric acid, or both.
30 . The stimulation fluid of claim 27 , wherein the aqueous medium comprises produced water.