Signal stacking in fiber optic distributed acoustic sensing
First Claim
1. A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprising:
- a) providing a plurality of received optical signals resulting from the transmission of an optical signal into a fiber optic cable that includes a sensing apparatus comprising a plurality of substantially parallel fiber lengths whereby each received optical signal comprises a portion of the optical signal that has been backscattered from a segment of a different fiber length;
b) processing the received optical signals from the segments of the different fiber lengths so as to effectively align the segments with one location of interest along the sensing apparatus before proceeding to step c), wherein the different segments together correspond to a single selected location along the sensing apparatus; and
c) on a processor, processing the received optical signals so as to obtain information about an acoustic signal received at the different segments there by obtaining practically simultaneous multiple detections by the different segments of the acoustic signals at the single selected location along the sensing apparatus.
2 Assignments
0 Petitions
Accused Products
Abstract
A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprises a) transmitting an optical signal into a fiber optic cable (14) that includes a sensing apparatus (20) comprising a plurality of substantially parallel fiber lengths (24), b) collecting from the sensing apparatus a plurality of received optical signals, each received signal comprising a portion of the transmitted signal that has been reflected from a different segment of a cable length, wherein the different segments are each in different cable lengths and correspond to a single selected location along the sensing cable, and c) processing the collected signals so as to obtain information about an acoustic signal received at the different segments. The cable may be ribbon cable and the lateral distance between the different segments may be less than 10 meters.
86 Citations
9 Claims
-
1. A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprising:
-
a) providing a plurality of received optical signals resulting from the transmission of an optical signal into a fiber optic cable that includes a sensing apparatus comprising a plurality of substantially parallel fiber lengths whereby each received optical signal comprises a portion of the optical signal that has been backscattered from a segment of a different fiber length; b) processing the received optical signals from the segments of the different fiber lengths so as to effectively align the segments with one location of interest along the sensing apparatus before proceeding to step c), wherein the different segments together correspond to a single selected location along the sensing apparatus; and c) on a processor, processing the received optical signals so as to obtain information about an acoustic signal received at the different segments there by obtaining practically simultaneous multiple detections by the different segments of the acoustic signals at the single selected location along the sensing apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification