Apparatus, Computer Readable Medium, and Program Code for Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors and a Downhole Broadband Transmitting System

摘要

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.

主权项

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 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, 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; transforming the raw acoustic sensor data into the frequency domain, filtering the transformed data, and performing one or more of 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, andderiving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.