DAS method of estimating fluid distribution
First Claim
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1. A method of optimizing fracturing in a well, the method comprising:
- a) recording distributed acoustic sensing (DAS) noise intensity signals from a well during a fracturing operation;
b) deriving DAS intensity traces from the recorded DAS noise intensity signals, wherein each said DAS intensity trace is a recording of DAS noise intensity over a span of a pre-determined number of fiber depths averaged over a predetermined period of time, and wherein each said trace does not overlap with other said traces;
c) locating a baseline channel having no perforations;
d) calculating a volumetric flow rate Q for each said perforation cluster using the following equation;
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Abstract
This disclosure describes a method of calculating fluid distribution from a hydraulically fractured well, especially during a plug-and-perf hydraulic fracturing operation. The Distributed Acoustic Sensing (DAS) data is used to quantify the fluid distribution in separate perf clusters during fracturing, and the result can be used for completion design and optimization, hydraulic fracturing, and ultimately for oil and gas production.
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Citations
17 Claims
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1. A method of optimizing fracturing in a well, the method comprising:
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a) recording distributed acoustic sensing (DAS) noise intensity signals from a well during a fracturing operation; b) deriving DAS intensity traces from the recorded DAS noise intensity signals, wherein each said DAS intensity trace is a recording of DAS noise intensity over a span of a pre-determined number of fiber depths averaged over a predetermined period of time, and wherein each said trace does not overlap with other said traces; c) locating a baseline channel having no perforations; d) calculating a volumetric flow rate Q for each said perforation cluster using the following equation; - View Dependent Claims (2, 3, 4, 5)
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6. A system for calculating volumetric flow rate through one or more perforation clusters inside a wellbore, comprising:
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a) a distributed acoustic sensing (DAS) monitoring device including an optical fiber that runs along the length of the wellbore, wherein the DAS optical fiber is coupled to an interrogating unit for emitting interrogating signals, the DAS monitoring device detects DAS noise intensity signals when strain or temperature deforms the optical fiber; b) a computer coupled to the DAS monitoring device for recording DAS noise intensity signals detected by the DAS monitoring device; c) wherein the computer performs the following steps to obtain volumetric flow rates of the hydraulic fluid through each said perforation cluster; i) deriving DAS intensity traces from the recorded DAS noise intensity signals, wherein each said DAS intensity trace is a recording of DAS noise intensity over a span of a pre-determined number of fiber depths averaged over a predetermined period of time, and wherein each said trace do not overlap with other said traces; ii) locating the depths of each said perforation cluster inside said well; iii) locating a baseline channel having no perforation for each said trace; iv) calculating a volumetric flow rate Q for each said perforation cluster using the following equation; - View Dependent Claims (7, 8, 9)
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10. A method of plug and perf fracturing a well, the method comprising:
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a) recording distributed acoustic sensing (DAS) noise intensity signals from a well during a first stage of a plug and perf fracturing operation in said well; b) deriving DAS intensity traces from the recorded DAS noise intensity signals, wherein each said DAS intensity trace is a recording of DAS noise intensity over a span of a pre-determined number of fiber depths averaged over a predetermined period of time, and wherein each said trace do not overlap with other said traces; c) identifying the depths of each said perforation cluster inside said well; d) locating a baseline channel having no perforations; e) calculating a volumetric flow rate Q for each said perforation cluster using the following equation; - View Dependent Claims (11, 12, 13)
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14. A system for calculating volumetric flow rate in a perforation cluster inside a wellbore undergoing hydraulic fracturing process that injects hydraulic fluids into the wellbore, comprising:
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a) a distributed acoustic sensing (DAS) monitoring device including a optical fiber that runs along the length of the wellbore, wherein the DAS optical fiber is coupled to an interrogating unit for emitting interrogating signals, the DAS monitoring device detects DAS noise intensity signals when mechanical strain causes deformation to the optical fiber; b) a computer coupled to the DAS monitoring device for recording DAS noise intensity signals detected by the DAS monitoring device; c) wherein the computer performs the following steps to obtain volumetric flow rates of the hydraulic fluid through each said perforation cluster; i) deriving DAS intensity traces from the recorded DAS noise intensity signals, wherein each said DAS intensity trace is a recording of DAS noise intensity over a span of a pre-determined number of fiber depths averaged over a predetermined period of time, and wherein each said trace do not overlap with other said traces; ii) locating the depths of each said perforation cluster inside said well; iii) locating a baseline channel having no perforation for each said trace; iv) calculating a volumetric flow rate Q for each said perforation cluster using the following equation; - View Dependent Claims (15, 16, 17)
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Specification