Frozen chamber for distributed acoustic sensing (DAS) configuration tests and disposable deployment
A method includes providing a distributed acoustic sensing (DAS) system and a fiber sample. The DAS system includes a chamber and a signal generator positioned proximate to and outside the chamber. The method further includes manipulating the fiber sample into a desired shape, filling the chamber with a freezable liquid, wherein the freezable liquid is provided at room temperature, and placing the fiber sample into the chamber. The method also includes recording a first set of room temperature baseline measurements, freezing the freezable liquid, and recording a first set of frozen baseline measurements. The method further includes performing strain-sensing measurements while the signal generator is active, and melting the freezable liquid.
1 . A method comprising:
providing a distributed acoustic sensing (DAS) system and a fiber sample,
wherein the DAS system comprises:
a chamber, and
a signal generator positioned proximate to and outside the chamber;
manipulating the fiber sample into a desired shape;
filling the chamber with a freezable liquid, wherein the freezable liquid is provided at room temperature;
placing the fiber sample into the chamber;
recording a first set of room temperature baseline measurements;
freezing the freezable liquid;
recording a first set of frozen baseline measurements;
performing strain-sensing measurements while the signal generator is active; and
melting the freezable liquid.
2 . The method of claim 1 further comprising:
removing the fiber sample from the chamber;
manipulating the fiber sample into a second desired shape;
placing the fiber sample into the chamber;
recording a second set of room temperature baseline measurements;
freezing the freezable liquid;
recording a second set of frozen baseline measurements;
performing strain-sensing measurements while the signal generator is active; and
melting the freezable liquid.
3 . The method of claim 1 , wherein manipulating the fiber sample into a desired shape comprises wrapping the fiber sample around a mould.
4 . The method of claim 3 , wherein the mould comprises a wire framework or a cylindrical liner.
5 . The method of claim 1 , wherein manipulating the fiber sample into a desired shape comprises covering the fiber sample with a bendable, shape-preserving material and forming the fiber sample into the desired shape.
6 . The method of claim 1 , wherein the chamber is selected from a group consisting of a cylindrical pipe, a wellbore, an excavated borehole, and a rectangular box.
7 . The method of claim 1 , wherein freezing the freezable liquid comprises placing the DAS system into an industrial cooler and monitoring a temperature of the fiber sample.
8 . The method of claim 1 , wherein freezing the freezable liquid comprises providing a tube in the chamber, wherein the tube is configured to supply and circulate liquid nitrogen or refrigerating freon to and through the chamber.
9 . The method of claim 1 , wherein the signal generator is selected from a group consisting of a seismic vibrator, an ultrasonic transducer, or a low-frequency source of quasi-static perturbations.
10 . The method of claim 1 , wherein melting the freezable liquid comprises positioning the DAS system in a warm location or positioning a heater proximate to the chamber.
11 . The method of claim 1 , wherein melting the freezable liquid comprises providing a tube in the chamber, wherein the tube is configured to supply and circulate hot liquids to and through the chamber.
12 . A frozen distributed acoustic sensing (DAS) system comprising:
a chamber;
a freezable liquid disposed within the chamber;
a signal generator positioned proximate to and outside the chamber; and
a fiber sample configured to be manipulated into one or more desired shapes.
13 . The frozen DAS system of claim 12 , wherein the chamber is selected from a group consisting of a cylindrical pipe, a wellbore, an excavated borehole, and a rectangular box.
14 . The frozen DAS system of claim 12 , wherein the signal generator is selected from a group consisting of a seismic vibrator, an ultrasonic transducer, or a low-frequency source of quasi-static perturbations.
15 . The frozen DAS system of claim 12 , wherein the fiber sample is configured to be wrapped around a mould to form the one or more desired shapes.
16 . The frozen DAS system of claim 15 , wherein the mould comprises a wire framework or a cylindrical liner.
17 . The frozen DAS system of claim 12 , wherein the fiber sample further comprises a bendable, shape-preserving coating.
18 . The frozen DAS system of claim 12 , wherein the freezable liquid comprises water.
19 . The frozen DAS system of claim 12 , further comprising a tube disposed within the chamber, wherein the tube is provided to supply a hot liquid or a cold liquid to and through the chamber.
20 . The frozen DAS system of claim 19 , further comprising a pump configured to propel the hot liquid or the cold liquid through the tube.