Segmented Acid Fracturing for Carbonate Reservoirs

The long interval reservoir is divided into multiple sections using sliding sleeves that can be positioned at different depths. Each sliding sleeve can be independently activated to create fractures at specific locations, enabling segmented stimulation of the reservoir interval. This segmentation allows targeted treatment of different reservoir zones with varying properties, improving overall reconstruction effectiveness.

The patent applies different acid fracturing strategies to different reservoir sections based on local characteristics. By using multiple sliding sleeves at different positions, each section can receive customized acid injection parameters (volume, pressure, timing) suited to its specific permeability and porosity characteristics, achieving local optimization of fracture quality and production potential.

The system uses dynamically adjustable sliding sleeves that can be positioned and activated in sequence rather than all at once. This dynamic approach allows the construction team to adjust the fracturing plan based on real-time pressure responses and production data, optimizing the balance between transformation strength and construction complexity without requiring predetermined fixed configurations.

The sliding sleeves are pre-positioned at desired locations during well completion before the acid fracturing operation begins. This preliminary placement allows for careful planning of fracture locations and spacing, enabling optimization of transformation strength while avoiding the complexity of real-time adjustments during high-pressure acid injection operations.

The acid fracturing operation is conducted in periodic stages, with each sliding sleeve activated sequentially rather than simultaneously. This periodic activation allows pressure to be managed in discrete steps, with each stage creating fractures in a specific zone before moving to the next. This approach improves fracture distribution across the interval while keeping peak wellhead pressure within manageable limits compared to simultaneous multi-zone fracturing.

The sliding sleeves are pre-positioned and sealed off from one another, creating isolated zones before acid injection begins. This preliminary zoning allows pressure to be contained within specific intervals, preventing pressure buildup across the entire wellhead system and enabling better control of construction pressure while achieving distributed fracture networks through sequential activation.