In order to ensure the accuracy and data acquisition quality of downhole
microseismic monitoring and observation system design, taking the actual downhole microseismic monitoring of a horizontal well in Songliao
Basin as an example, the design of microseismic monitoring data acquisition and observation system, the quality control methods of key links
such as geophone rotation, velocity model correction, first break pickup and event location were applied to ensure the accuracy microseismic
monitoring. Meanwhile, the comprehensive analysis and evaluation of microseismic events were carried out by integrating logging data, three
dimensional seismic data and fracturing construction data. Finally, the microseismic events were selecteded by using data signaltonoise
ratio statistics map, magnitudedistance map and timedistance map, and the data set which can objectively reflect fracturing was obtained.
Comprehensive judgment shows that the production rate of well H1 after fracturing was not ideal, which further proved that it is not easy to
control the simultaneous initiation and fracturing of two perforation points in the same section under geological conditions. When optimizing the
fracturing design of another adjacent horizontal well, the interval between segments was shortened and only one hole was perforated in each
segment for fracturing. The screening of microseismic events can play an important role in optimizing fracturing design.