Prediction of formation and stratigraphic layers while drilling

Patent metadata

Field	Value
Publication number	US-2016341834-A1
Application number	US-201514717162-A
Country	US
Kind code	A1
Filing date	May 20, 2015
Priority date	May 20, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

An embodiment of a method of predicting a location of one or more features of an earth formation during a downhole operation includes acquiring reference data and identifying one or more reference data sections, each reference data section corresponding to a feature of interest and having an associated depth or depth interval, deploying a drilling assembly and drilling a target borehole in the earth formation, and performing measurements during the operation by a downhole measurement device to generate measurement data. The method also includes performing one or more correlations of the one or more measurement data sections with one or more reference data sections; and predicting at least one of a depth of a subsequent feature of interest located beyond a current carrier depth and a point in time of a future event associated with the subsequent feature of interest based on the correlation.

First claim

What is claimed is:

1 . A method of predicting a location of one or more features of an earth formation during a downhole operation, comprising:
acquiring reference data and identifying one or more reference data sections, each reference data section corresponding to a feature of interest and having an associated depth or depth interval; deploying a drilling assembly and drilling a target borehole in the earth formation, and performing measurements during the operation by a downhole measurement device to generate measurement data; performing one or more correlations of one or more measurement data sections with one or more reference data sections; and predicting at least one of a depth of a subsequent feature of interest located beyond a current carrier depth and a point in time of a future event associated with the subsequent feature of interest based on the correlation.

2 . The method of claim 1 , wherein the reference data includes measurements taken from a reference borehole disposed in a region of the formation expected to have one or more stratigraphic layers common to both the target borehole and the reference borehole.

3 . The method of claim 1 , wherein the reference data includes seismic measurements of the formation.

4 . The method of claim 1 , further comprising performing an action in response to predicting at least one of the depth of the subsequent feature and the point in time of the event, the action including at least one of: generating an alert, updating a plan for landing or steering the target borehole, updating or modifying a model of the formation, changing a rate of penetration of the drilling assembly, adjusting a drilling dynamics parameter, adjusting the drilling direction, adjusting one or more mud properties, changing, removing, or adding a downhole component, setting a casing, and adjusting one or more operational parameters.

5 . The method of claim 1 , wherein the reference data section includes at least one of: a data value change exceeding or falling below a selected threshold, and a distinctive pattern of data values associated with the feature of interest.

6 . The method of claim 1 , wherein performing the one or more correlations includes calculating a shift of the depth or time of each corresponding reference data section so that a depth of the reference data section corresponds to a depth of the one or more measurement data sections, and predicting includes estimating a depth or time of the subsequent feature of interest by adjusting a depth or time of a reference data section corresponding to the subsequent feature of interest based on the shift.

7 . The method of claim 1 , wherein performing the one or more correlations includes generating a data point for one or more depth or time shifts as a function of depth or time.

8 . The method of claim 1 , wherein the feature of interest includes at least one of: a change in lithology or facies of the formation, a surface of a stratigraphic layer, and a surface of a zone with relatively high pressure.

9 . The method of claim 1 , wherein the event includes penetrating or approaching at least one of: a change in lithology or facies of the formation, a surface of a stratigraphic layer, and a surface of a zone with relatively high pressure.

10 . The method of claim 1 , wherein performing the one or more correlations includes identifying the one or more reference data sections by calculating an absolute change in values of the reference data, calculating a relative change in the values, and correlating the absolute change or the relative change with the feature of interest.

11 . The method of claim 10 , wherein performing the one or more correlations includes monitoring the measurement data and selecting a depth interval in which an absolute change in value of the measurement data is within a selected range of the absolute change of the reference data, or in which a relative change in the value of the measurement data is within a selected range of the relative change of the reference data.

12 . A system for predicting location of one or more features of an earth formation during a downhole operation, comprising:
a carrier configured to be deployed in a borehole in the earth formation, the carrier including a drilling assembly configured to operate in a target borehole in the earth formation; a downhole measurement device configured to perform measurements during the downhole operation in the target borehole to generate measurement data; and a processor configured to perform: acquiring reference data and identifying one or more reference data sections, each reference data section corresponding to a feature of interest and having an associated depth or depth interval; acquiring measurement data generated by performing measurements during the operation by a downhole measurement device; performing one or more correlations of one or more measurement data sections with one or more reference data sections; and predicting at least one of a depth of a subsequent feature of interest located beyond a current carrier depth and a point in time of a future event associated with the subsequent feature of interest based on the correlation.

13 . The system of claim 12 , wherein the reference data includes measurements taken from a reference borehole disposed in a region of the formation expected to have one or more stratigraphic layers common to both the target borehole and the reference borehole.

14 . The method of claim 12 , wherein the processor is configured to perform an action in response to the drilling assembly approaching the predicted depth or point in time, the action including at least one of: generating an alert, updating a plan for landing or steering the target borehole, updating or modifying a model of the formation, changing a rate of penetration of the drilling assembly, adjusting a drilling dynamics parameter, adjusting the drilling direction, adjusting one or more mud properties, changing, removing, or adding a downhole component, setting a casing, and adjusting one or more operational parameters.

15 . The system of claim 11 , wherein the reference data section includes at least one of: a data value change exceeding or falling below a selected threshold, and a distinctive pattern of data values associated with the feature of interest.

16 . The system of claim 11 , wherein performing the one or more correlations includes generating a data point for one or more depth or time shifts as a function of depth or time.

17 . The system of claim 16 , wherein generating the data point for the one or more depth or time shifts includes constructing a curve, identifying a reference data section corresponding to the subsequent feature of interest, and calculating a depth in the target borehole of the subsequent feature of interest by applying a depth interval of the identified reference data section to the curve.

18 . The system of claim 12 , wherein performing the one or more correlations includes calculating a shift of the depth or time of each corresponding reference data section so that a depth of the reference data section corresponds to a depth of the one or more measurement data sections, and predicting includes adjusting at least one of the depth and the time of a subsequent feature of interest based on the shift.

19 . The system of claim 12 , wherein performing the one or more correlations includes identifying the one or more reference data sections by calculating an absolute change in values of the reference data, calculating a re

Assignees

• Bartetzko Anne
• Wessling Stefan
• Baker Hughes Inc

Inventors

• Bartetzko Anne
• Wessling Stefan

Classifications

• G01V1/50 Primary

  Analysing data · CPC title

• G01V1/282 Primary

  Application of seismic models, synthetic seismograms · CPC title