Optimization of In-Stage Multi-Cluster Temporary Plugging Scheme Based on Optical Fiber Monitoring

It is necessary to temporarily plug the dominant fluid inlet cluster to achieve uniform transformation between clusters in stages. The current temporary plugging schemes are mainly developed based on the indoor temporary plugging test. However, there is a certain gap between the indoor temporary plugging test conditions and the actual fracturing conditions, resulting in an unsatisfactory temporary plugging effect. In order to provide a basis for optimizing in-stage multi-cluster fracturing temporary plugging schemes, a horizontal well of the Carboniferous system in Xinjiang Oilfield was selected, and 12 sets of temporary plugging schemes were designed for five fracturing stages to plug holes or fracture. The out-of-pipe optical fiber monitoring technology was used to monitor the changes in fluid intake of each perforation cluster in stages before and after temporary plugging, and the temporary plugging effect was judged accordingly. After the implementation of 12 sets of temporary plugging schemes in Well A, no diversion between clusters was detected, indicating the ineffectiveness of temporary plugging. The inefficiency is attributed to factors such as the mismatched diameter of the plugging ball with the hole and the random hole orientation, making it challenging to block high-edge holes. In order to avoid perforating the optical fiber, the ruptured disc is a circular through-hole structure, which is not conducive to blocking the hole with the temporary plugging ball. Therefore, improvement measures of temporary plugging schemes were proposed: applying temporary plugging balls with a diameter the same as the hole to block the hole; adding fibers and temporary plugging agents with small particles or using rope temporary plugging agents; making low-edge holes shot through directional perforation; utilizing a tapered hole structure for the ruptured disc.