Work

Induced Casing Deformation in Hydraulically Fractured Shale Gas Wells: Risk Assessment, Early Warning, and Mitigation

Year: 2024

Type: article

Abstract: Casing deformation is a key factor affecting thse scale and efficiency of shale gas development in recent years. A fast and efficient integrated prevention, control and treatment technology of casing deformation is of great significance in theory and application. This paper combines geological mechanics analysis and multi-cluster fracture propagation to investigate the technology of risk evaluation, early warning & identification, and control & treatment of casing deformation and its application. A method for dynamic and static evaluation of casing deformation risk levels and types is proposed, and an index system incorporating stress, fracture, time, and space factors is established. This four-factor evaluation method is more aligned with field conditions. A method for early warning and identification of casing deformation based on fracture monitoring and operation curve is proposed, and the dominant engineering factors for casing deformation are clarified. It is indicated that the total fluid volume per stage has greater impact on casing deformation than high pump rate. Prevention and control of casing deformation should be realized preferentially by optimizing fracturing parameters. Moreover, existing technologies for treating casing deformation are reviewed, defining the small-diameter bridge plug staged fracturing + small-size gun perforation and long-stage multi-cluster asynchronous fracture initiation + composite temporary plugging and diversion as the major technologies. The study results provide a support for significant reduction of casing deformation rate during fracturing and improvement of effective stimulation degree in the casing deformation section in shale gas wells in southern Sichuan Basin, and they are referential for subsequent research.

Source: Processes

DOI: 10.3390/pr12092057