Application of Seismic and Micro-seismic in Adjusting the Sequence of Multi-Stage Fracturing
摘要
During hydraulic fracturing, casing deformation often occurs, which affects the efficiency and effectiveness of fracturing. We can effectively identify the perforation stage of casing deformation using geophysical methods, but it cannot avoid the occurrence of casing deformation. Therefore, it is particularly important to optimize the sequence of multi-stage fracturing to avoid casing deformation or reduce the impact of casing deformation. In order to avoid casing deformation during fracturing or reduce the impact of casing deformation on the un-fractured perforated stage, this paper proposes an optimized programme for the sequence of multi-stage fracturing based on the geophysical identification of the perforation stage with casing deformation risk. This programme includes, first of all, applying geophysical data to identify natural-fractures, identifying high-risk perforation stages, and preliminarily preparing the sequence of fracturing for each perforation stage before fracturing. Secondly, during the fracturing, we apply micro-seismic events to explain artificial-fractures, and determine the activity of natural-fractures based on the positional relationship between artificial-fractures and natural-fractures, we then compile the sequence of fracturing for each perforation stage. The perforation stage affected by active natural-fractures should be prioritized for fracturing. The proposed solution has been applied in multi-well zipper fracturing, which can effectively reduce the impact of more than 60% of casing deformation on the un-fractured perforation stage. This article innovatively proposes to determine the relationship between natural-fractures and artificial-fractures based on 3d-seismic and micro-seismic, determine the activity of natural-fractures, optimize the sequence of multi-stage fracturing and perforation stages, which is beneficial for improving fracturing efficiency and effectiveness.