A workflow for the refracturing design of horizontal well with coupled geomechanics and reservoir simulation in tight oil reservoir

Refracture technique has been a common practice to mitigate the flow rate decline and revitalize wells productivity. However, refracturing design in tight resource wells is difficult because the dynamic stress changes due to long term reservoir depletion. This paper presents a workflow for the refracturing in tight oil reservoirs with the geological modelling, geomechanical modeling and refracturing fracture simulation. The combination of the core, logging, and seismic data were used to establish the reservoir, natural fracture, rock mechanical, and in-situ stress models. Moreover, the perforations in the refracturing stage were also selected with three main factors, including the remaining oil distribution, low formation pressure and average production index per pressure decline rate. Thus, dense cluster spacing fracturing and temporary plugging methods can be applied to create new and old fractures depends on the updated reservoir properties. Using a loose coupled technique, the in-situ stress prior to refracturing was computed and local dynamic stress change can be found along the horizontal well lateral stage. Numerical simulations indicate fluid injection volume and pump rate have critical influences on the reservoir stimulated volume (SRV) while the best scenarios can be determined for the given case. Compared with the initial fracturing, the SRV volume of the refracturing is increased by 150%, which is beneficial for oil production increase in this area. The field application demonstrates that refracturing can greatly improve well production in the tight oil reservoir.