GEOSTEERING BOREHOLES USING DISTRIBUTED ACOUSTIC SENSING Russian patent published in 2019 - IPC E21B47/224 

FIELD: soil or rock drilling; mining.

SUBSTANCE: invention relates to geosteering while drilling boreholes. In particular, a method is disclosed for estimating the location of a borehole, which includes: disposing an acoustic sensor in a first borehole in an earth formation, the acoustic sensor including a plurality of measurement locations disposed along a length of the first borehole; drilling a portion of a second borehole in the earth formation using a drilling assembly; receiving distributed acoustic measurement data over a time period during the drilling by the plurality of measurement locations, the acoustic measurement data based at least in part due to an acoustic signal generated by the drilling assembly and detected by the plurality of measurement locations, and include multiple seismic traces, each of which is associated with a different location along the first borehole; processing the measurement data to estimate a distance between the drilling assembly and the acoustic sensor, the data processing including the cross-correlation of multiple seismic traces and calculating the maximum of the cross-correlation associated with each seismic trace, generating a graph of the maximum of the cross-correlation and estimating said distance based on the vertex of this graph; and controlling drilling direction parameters based on distance.

EFFECT: technical result is a wider range of tools for monitoring and determining the location of the downhole tool, ensuring the accuracy of directional drilling of a borehole.

18 cl, 5 dwg