Apparatus, computer readable medium, and program code for evaluating rock properties while drilling using downhole acoustic sensors and a downhole broadband transmitting system
First Claim
1. A non-transitory computer readable medium having processor readable petrophysical properties analyzing program code embodied on the computer readable medium, the processor readable program code for programming one or more processors to perform operations for analyzing properties of rock in a formation in real-time during drilling, the processor readable program code comprising a set of instructions that when executed by the one or more processors, cause the one or more processors to perform the operations 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,receiving digitized raw acoustic sensor data from the surface data acquisition unit, the digitized 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;
transforming the digitized raw acoustic sensor data into the frequency domain,filtering the transformed data, andperforming the following processing operations;
deriving a plurality of acoustic characteristics from the filtered data, the plurality of acoustic characteristics including mean frequency and normalized deviation of frequency;
comparing the mean frequency and the normalized deviation of frequency of the rock undergoing drilling with mean frequency and normalized deviation of frequency of a plurality of rock samples having different known lithologies;
identifying lithology type of the rock undergoing drilling responsive to the operation of comparing;
deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to identify one or more petrophysical properties of rock undergoing drilling; and
providing the one or more petrophysical properties of rock undergoing drilling or the lithology type of the rock undergoing drilling to a driller to assist in drilling operations.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus, computer readable medium, and program code for identifying rock properties in real-time during drilling, are provided. An example of an embodiment of such an apparatus includes a downhole sensor subassembly connected between a drill bit and a drill string, acoustic sensors operably coupled to a downhole data interface, and a surface computer operably coupled to the downhole data interface. The computer can include a petrophysical properties analyzing program configured or otherwise adapted to perform various operations including 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 acoustic sensor data into the frequency domain, filtering the transformed data, deriving a plurality of acoustic characteristics from the filtered data 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.
110 Citations
15 Claims
-
1. A non-transitory computer readable medium having processor readable petrophysical properties analyzing program code embodied on the computer readable medium, the processor readable program code for programming one or more processors to perform operations for analyzing properties of rock in a formation in real-time during drilling, the processor readable program code comprising a set of instructions that when executed by the one or more processors, cause the one or more processors to perform the operations 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, receiving digitized raw acoustic sensor data from the surface data acquisition unit, the digitized 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; transforming the digitized raw acoustic sensor data into the frequency domain, filtering the transformed data, and performing the following processing operations; deriving a plurality of acoustic characteristics from the filtered data, the plurality of acoustic characteristics including mean frequency and normalized deviation of frequency; comparing the mean frequency and the normalized deviation of frequency of the rock undergoing drilling with mean frequency and normalized deviation of frequency of a plurality of rock samples having different known lithologies; identifying lithology type of the rock undergoing drilling responsive to the operation of comparing; deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to identify one or more petrophysical properties of rock undergoing drilling; and providing the one or more petrophysical properties of rock undergoing drilling or the lithology type of the rock undergoing drilling to a driller to assist in drilling operations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A non-transitory computer readable medium having processor readable petrophysical properties analyzing program code embodied on the computer readable medium, the processor readable program code for programming one or more processors to perform operations for analyzing properties of rock in a formation in real-time during drilling, the processor readable program code comprising a set of instructions that when executed by the one or more processors, cause the one or more processors to perform the operations of:
-
receiving 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 one or more of the following processing operations; deriving a plurality of acoustic characteristics from the raw acoustic sensor data, the plurality of acoustic characteristics including mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power, wherein the apparent power represents the power of the acoustic signal; comparing the mean frequency, the normalized deviation of frequency, the mean amplitude, the normalized deviation of amplitude, and the apparent power for the rock undergoing drilling with mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power for a plurality of rock samples having different known lithologies, the mean frequency and normalized deviation of frequency being examined together and the mean frequency and the mean amplitude being examined together to determine an amount of correlation of the acoustic characteristics associated with the rock undergoing drilling and the acoustic characteristics associated with the rock samples, the operation of comparing being performed substantially continuously during drill bit steering; and performing one or more of the following responsive to the operation of comparing; identifying lithology type of the rock undergoing drilling, and determining a location of a formation boundary encountered during drilling; and providing the lithology type of the rock undergoing drilling or the location of the formation boundary to a driller to assist in drilling operations. - View Dependent Claims (12, 13, 14, 15)
-
Specification