Corrective scaling of interpreted fractures based on the microseismic detection range bias correction

Patent metadata

Field	Value
Publication number	US-2016178798-A1
Application number	US-201414577751-A
Country	US
Kind code	A1
Filing date	Dec 19, 2014
Priority date	Dec 19, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A method for correcting a fracture model of a reservoir includes receiving a seismic signal from seismic events due to a plurality of stimulated reservoir stages to provide detected seismic event information and estimating a number of undetected seismic events and a magnitude for each of the undetected seismic events to provide undetected seismic event information for each stage. The detected seismic event information and the undetected seismic event information provide corrected seismic event information for each stage. The method further includes calculating a scaling factor for each stage using a scalar property of the corresponding stage and a reference stage scalar property, applying the scaling factor for each stage to the corrected seismic event information to provide scaled seismic event information for each stage, and correcting the fracture model with the scaled seismic event information for each stage to provide a corrected fracture model.

First claim

What is claimed is:

1 . A method for correcting a fracture model of a reservoir, the method comprising:
stimulating an earth reservoir using a stimulation apparatus configured to generate a plurality of seismic events in the reservoir; receiving a seismic signal having a magnitude from each seismic event in a plurality of seismic events that are in a plurality of stimulated stages in the reservoir to provide detected seismic event information in each of the stages, the seismic signal being received by an array of seismic receivers; selecting a stage in the plurality of stages as a reference stage according to a selection criterion; estimating a number of undetected seismic events and a magnitude for each of the undetected seismic events to provide undetected seismic event information for each stage in the plurality of stages, the number of undetected seismic events and corresponding magnitudes for each stage in the plurality of stages being estimated using each of the detected seismic events and corresponding magnitudes for the corresponding stage, wherein the detected seismic event information and the undetected seismic event information provide corrected seismic event information for each stage in the plurality of stages; determining a scalar property for each stage in the plurality of stages; calculating a scaling factor for each stage using the scalar property of the corresponding stage and the scalar property of the reference stage, the scaling factor relating the scalar property of the corresponding stage to the scalar property of the reference stage; applying the scaling factor for each stage to the corrected seismic event information for the corresponding stage to provide scaled seismic event information for each stage in the plurality of stages; and correcting the fracture model with the scaled seismic event information for each stage in the plurality of stages to provide a corrected fracture model; wherein the receiving, selecting, estimating, determining, calculating, applying and correcting are implemented by an algorithm executed by a processor.

2 . The method according to claim 1 , further comprising transmitting a signal comprising the corrected fracture model to a signal receiving device using an output interface.

3 . The method according to claim 2 , wherein the signal receiving device is a display or a printer and the method further comprises displaying the corrected fracture model to a user.

4 . The method according to claim 2 , wherein the signal receiving device is a storage medium or memory and the method further comprises storing the corrected fracture model.

5 . The method according to claim 1 , wherein the selection criterion comprises selecting the stage that is closest to the array of seismic receivers or the stage having the lowest magnitude of completeness.

6 . The method according to claim 1 , wherein the corrected seismic event information for each stage comprises a corrected fracture size or dimensions.

7 . The method according to claim 6 , further comprising applying a size constraint to the corrected fracture size.

8 . The method according to claim 7 , wherein the fracture is a bi-wing fracture and the size constraint forces the fracture to be symmetric with respect to the borehole.

9 . The method according to claim 7 , wherein the size constraint is such that reservoir connectivity to the borehole remains the same after application of the size constraint.

10 . The method according to claim 7 , wherein the size constraint is such that a fracture height is limited to a bedding thickness.

11 . The method according to claim 1 , further comprising estimating a stimulated reservoir volume using the scaled seismic event information for each of the stages.

12 . The method according to claim 11 , wherein applying comprises applying the scaling factor to each of the detected and undetected seismic events to provide scaled seismic events for each stage.

13 . The method according to claim 12 , further comprising determining a scalar attribute for each of the scaled seismic events for each stage.

14 . The method according to claim 13 , further comprising summing the scalar attributes for each of the scaled seismic events in each stage of events to provide a scaled stage scalar attribute.

15 . The method according to claim 14 , further comprising summing all stage scaled scalar attributes to estimate the stimulated reservoir volume.

16 . The method according to claim 1 , wherein the scaled seismic event information comprises a scalar attribute for each of the detected and undetected seismic events for each stage.

17 . A method for generating a fracture model of a reservoir, the method comprising:
receiving a seismic signal having a magnitude from each seismic event in a plurality of seismic events that are in a plurality of stimulated stages in the reservoir to provide detected seismic event information in each of the stages, the seismic signal being received by an array of seismic receivers; selecting a stage in the plurality of stages as a reference stage according to a selection criterion; estimating a number of undetected seismic events and a magnitude for each of the undetected seismic events to provide undetected seismic event information for each stage in the plurality of stages, the number of undetected seismic events and corresponding magnitudes for each stage in the plurality of stages being estimated using each of the detected seismic events and corresponding magnitudes for the corresponding stage, wherein the detected seismic event information and the undetected seismic event information provide corrected seismic event information for each stage in the plurality of stages; determining a scalar property for each stage in the plurality of stages; calculating a scaling factor for each stage using the scalar property of the corresponding stage and the scalar property of the reference stage, the scaling factor relating the scalar property of the corresponding stage to the scalar property of the reference stage; applying the scaling factor for each stage to the corrected seismic event information for the corresponding stage to provide scaled seismic event information for each stage in the plurality of stages; generating the fracture model with the scaled seismic event information for each stage in the plurality of stages to provide a corrected fracture model; and transmitting, using an output interface, a signal comprising the generated fracture model to a signal receiving device; wherein the receiving, selecting, estimating, determining, calculating, applying and correcting are implemented by an algorithm executed by a processor.

18 . A non-transitory computer readable medium comprising computer executable instructions for correcting a fracture model of a reservoir that when executed by a computer implements a method comprising:
receiving a seismic signal having a magnitude from each seismic event in a plurality of seismic events that are in a plurality of stimulated stages in the reservoir to provide detected seismic event information in each of the stages, the seismic signal being received by an array of seismic receivers; selecting a stage in the plurality of stages as a reference stage according to a selection criterion; estimating a number of undetected seismic events and a magnitude for each of the undetected seismic events to provide undetected seismic event information for each stage in the plurality of stages, the number of undetected seismic events and corresponding magni

Assignees

• Holland Marc
• Zhang Xiaomei
• Baker Hughes Inc

Inventors

• Holland Marc
• Zhang Xiaomei

Classifications

• E21B43/26 Primary

  by forming crevices or fractures · CPC title

• G01V99/005 Primary

  Physics · mapped topic

• E21B47/00

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title

• G01V1/48

  Processing data · CPC title

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title