The paper will provide details around a relatively low-cost completion method, using a two packer mechanical straddle system, which enables in selectively treating a single stage or cluster, by ensuring isolation above and below the target zone thereby leading to a flawless execution of the designed treatment. This particular straddle system can be deployed on coiled tubing leading to an overall improvement in operational efficiency when being deployed and moving from one stage to another, hence saving money for a producer in the long run. This paper will describe the details and capabilities of the straddle tool, along with some specifics from successfully completed wells. This paper will also outline a data driven workflow developed to assess re-fracturing (refrac) candidate wells and the application of said workflow to a group of wells in an unconventional Permian formation, that were planned to be treated by an operator in the area. Finally, the paper will relay a simulation approach used to assess the effect of said treatment on long-term production. The refrac candidate well that will be referenced in the paper was drilled and completed in a tight formation. The approach employed here uses both data-driven and physics-based modelling when choosing the best refracturing candidate and can be applied to any group of wells. The approach assumes that the production and initial completion data is available for the wells studied in order to screen for potential candidates, and a reservoir model is also available for the chosen candidates for forecasting EUR upsides.
This paper discusses details of a mechanical straddle system, by highlighting the case histories of successfully pumping both proppant and acid stimulation systems. In addition, this paper also delves into the criteria (which employs the production and initial completion data) used to select the aforementioned candidate well as a candidate for refrac. Once the selection process is outlined, a hydraulic fracturing treatment design is shown for the well. Results from the fracturing design were then used as input in a history matched reservoir/completion simulation to assess long-term production as a result of the refrac design. The candidate well was filtered through the data-driven approach, providing a means for de-risking based on well history and then well performance was evaluated through fracture modeling and reservoir simulation.
The workflow provides a thorough methodology that allows an engineer to pick candidate wells for refracturing and assess the wells’ potential production post refrac treatment. The well in question was filtered through the data-driven criteria and once selected, production history was matched through simulation and sensitivities for refrac were conducted to show the effect on long-term production
Importance of combining a robust straddle technology, which is entirely manipulated mechanically, with the ability to choose the right candidate for refrac/restimulation provides a customer with an opportunity of improving their ROI.