Integration of surface seismic, 3D VSP, and microseismic hydraulic fracture mapping to improve gas production in a tight complex reservoir

Abstract

Summary Completion techniques in tight hydrocarbon reservoirs typically include hydraulic fracturing to increase permeability. In this study surface seismic data, 3D VSP data, and microseismic mapping of induced hydraulic fractures were combined to understand the magnitude, direction, mechanisms, and lithologic controls on hydraulic fracturing in a tight gas reservoir. Fracture points were mapped from 3D surface seismic data, VSP data were used to tie borehole measurements to the surface seismic volumes, and 3D VSPs and offset VSPs were used to increase resolution and determine specific influences of reservoir zones or faults on the direction and magnitude of the fractures. Detailed velocity information obtained from multi-level multi-component VSP data (measured with the same instruments as the microseismic events) provided accurate locations of the measured fracture events in addition to providing well-constrained ties to the surface seismic volumes. Integration between disciplines improved the reliability of all of the data and provided the interpreter a unique opportunity to ‘see’ where the induced fractures occurred, thus highlighting fluid pathways within the complicated reservoir. These insights significantly improved design and implementation of hydraulic fractures. The integration methodology can be applied in other settings and projects.