The target well is a shale gas evaluation horizontal well with multi-stage fracturing. It uses a three-section drilling design, with a formation dip angle of less than 5°, a build-up point at 1,200 m, a landing point at 2,500 m, and a total depth of 4,860 m. The gas layer is relatively shallow overall. The horizontal section has an average porosity of 4.16%, and the TOC (Total Organic Carbon) average is 3.78%. The well is muti-stage fractured to enhance productivity.

During the development process, the water-gas ratio increased, the water content at the wellhead rose rapidly, and the pressure showed a significant decline. The pressure drop effect due to the water phase in the wellbore became evident, resulting in poor development performance for the single well.

Using coiled tubing, fiber optics were deployed to the target intervals, collecting distributed fiber optic sensing data under various operating conditions. Based on this, distributed fiber optic sensing data interpretation was performed, precisely characterizing the water production and gas production distribution across different fracturing stages and perforation clusters. The water production profile and gas production profile of the single well demonstrated high consistency, with the main contribution to production concentrated in the heel section of the horizontal well, accounting for 30% of total production. The production profile along the horizontal section exhibited poor uniformity.When the operating parameters were increased, the production pressure differential further expanded, leading to a noticeable increase in daily gas production in the low-pressure differential gas-producing intervals.

The interpretation results from the distributed fiber optic sensing provided valuable insights for optimizing single-well operating parameters, understanding the segment and cluster contribution differences to gas production, and evaluating the adaptability of the fracturing process. These findings serve as a reference for further optimization of the fracturing process for single wells.