US 2013/0075161 A1 · METHODS OF EVALUATING ROCK PROPERTIES WHILE DRILLING USING DOWNHOLE ACOUSTIC SENSORS AND A DOWNHOLE BROADBAND TRANSMITTING SYSTEM

Abstract

Methods of identifying rock properties in real-time during drilling, are provided. An example of such a method includes connecting a downhole sensor subassembly between a drill bit and a drill string, operably coupling acoustic sensors to a downhole data interface, and operably coupling a surface computer to the downhole data interface. The method can also include receiving raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling, transforming the raw data into the frequency domain, filtering the transformed data, and deriving a plurality of acoustic characteristics from the filtered data. This can be performed by a petrophysical properties analyzing program stored in memory of the computer. The method can also include deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.

Claims23

Dependent claims

A method of analyzing properties of rock in a formation in real-time during drilling, the method comprising the steps of:

sending sampling commands to a surface data acquisition unit in communication with a downhole data interface through a surface data interface and a communication medium extending between the surface data interface and the downhole data interface, the downhole data interface operably coupled to a plurality of acoustic sensors carried by a downhole sensor assembly, the raw acoustic sensor data representing an acoustic signal generated real-time as a result of rotational contact of a drill bit with rock during drilling;
receiving, by a computer, digitized raw acoustic sensor data from the surface data acquisition unit;
transforming the raw acoustic sensor data into the frequency domain;
filtering the transformed data;
and
performing, by the computer, one or more of the following processing steps:
deriving a plurality of acoustic characteristics from the filtered data, the plurality of acoustic characteristics including mean frequency and normalized deviation of frequency, and
deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.

5 more elements

A method of analyzing properties of rock in a formation in real-time during drilling, the method comprising the steps of:

receiving, by a computer, raw acoustic sensor data from a surface data acquisition unit in communication with a downhole data interface through a surface data interface and a communication medium extending between the surface data interface and the downhole data interface, the downhole data interface operably coupled to a plurality of acoustic sensors;
and
performing, by the computer, one or more of the following processing steps:
deriving a plurality of acoustic characteristics from the raw acoustic sensor data, the plurality of acoustic characteristics including mean frequency and normalized deviation of frequency, and
deriving petrophysical properties from the raw acoustic sensor data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.

2 more elements

A method of analyzing properties of rock in a formation in real-time during drilling, the method comprising the steps of:

receiving, by a computer, raw acoustic sensor data from a surface data acquisition unit in communication with a downhole data interface through a surface data interface and a communication medium extending between the surface data interface and the downhole data interface, the downhole data interface operably coupled to a plurality of acoustic sensors, the raw acoustic sensor data representing an acoustic signal generated real-time as a result of rotational contact of a drill bit with rock during drilling;
and
deriving a plurality of acoustic characteristics from the raw acoustic sensor data, the plurality of acoustic characteristics including mean frequency and normalized deviation of frequency.

A method of analyzing properties of rock in a formation in real-time during drilling, the method comprising the steps of

receiving, by a computer, raw acoustic sensor data from a surface data acquisition unit in communication with a downhole data interface through a surface data interface and a communication medium extending between the surface data interface and the downhole data interface, the raw acoustic sensor data representing an acoustic signal generated real-time as a result of rotational contact of a drill bit with rock during drilling;
and
deriving petrophysical properties from the raw acoustic sensor data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.

Dependencies are inferred from the claim text.

Methods of evaluating rock properties while drilling using downhole acoustic sensors and a downhole broadband transmitting system

Life of this patent

Methods of evaluating rock properties while drilling using downhole acoustic sensors and a downhole broadband transmitting system

Life of this patent

Abstract

Claims23