Abstract:Liaohe oil field, China, implemented a hydraulic fracture of well L606-6, together for the 5 sub-layers at a depth about 2900 m in 02/10/2018. The vector scanning (VS) was used to monitor the process by a surface microseismic network, for checking up the monitoring quality and stimulation effect. We followed strictly the necessary conditions required by VS application,such that the signal-to-noise was satisfied with quality and its reliable average value of 3.6%. The final fracture net shows a length of 400 m along a main orientation of NE30 occupying an area about 6.4x104 m2; the net consists of two-group fractures with different orientations of NE30 and NE90,seperately; the height of the net is ≥50 m. The microseismic activity is apparently intermittent: in the earlier half term, each seismic group needs to wait a couple of minutes before to accumulate enough injected energy; and later it becomes about ten minutes. The greater activity each time happens, randomly, in the different one or two orientations at a part of the final net, which is called "fill up". The two sub-fracture groups indicate that the direction range of in situ maximum principal stress should then be between NE30 and NE90. This is a typical stimulation and its microseismic monitoring on surface. Using L606-6 for reference, we also performed hydro-fracture for other three wells close to L606-6, and used downhole array in the microseismic monitoring; the final fracture nets of all 4 wells are similar each other, such as the surface detection is verified in a way.