Restimulation Design Considerations and Case Studies of Haynesville Shale

摘要

This paper discusses a method for, and case histories of, using an environmentally acceptable, selfremoving particulate diverter that has proven to be successful in the refracturing efforts of horizontal unconventional reservoirs. This method is typically chosen for its low cost, self-assembly, self-removal, and ease of addition into treatment. An outline of the evolution of restimulation design, typical procedures, and candidate selection strategies is provided. The ability to add reservoir contact, restore conductivity, and remediate blockage makes this technique desirable. Different strategies can be applied when using this product and are typically customized to the particular candidate well selected for the refracturing treatment. The treatment design is also often customized to the particular candidate well; however, key components of the design are outlined. Candidate wells for refracturing typically fall into one or more categories: Understimulation occurred in the original completion. Production damaging mechanisms are present. A low investment lease retention strategy is required. A pressure-sink mitigation strategy is necessary for infill completions. A typical procedure will consist of casing inspection, wellbore cleanout, addition of perforations, and flowback considerations. In this study, different Haynesville shale refracturing treatments and results are compared. The evolution of treatment designs, such as carrier fluid, fluid volume, proppant volume, and diverting methodology, are explained. The results and the theory behind these changes are outlined, along with the economic viability of refracturing treatments. Pre/post-treatment estimated ultimate recovery (EUR) calculations are compared, along with treatment pressure trend analysis. The EUR uplift from the refracturing treatments is used to show the economic viability.