Optimizing Cluster Performance in Horizontal Wells: A High-Resolution Approach Using High-Precision Temperature and Spectral Acoustics

Modern horizontal wells completed with plug-and-perf designs often exhibit uneven perforation cluster performance. In fact, only ~60% of clusters typically contribute significantly to production in geometrically completed wells, leaving considerable room for improvement. This makes cluster-by-cluster performance evaluation crucial for optimizing hydrocarbon recovery and refining completion strategies. By pinpointing which fracture clusters are underperforming or inactive, operators can take corrective actions to improve stimulation effectiveness and gain a better understanding of the reservoir. The study employs High Precision Temperature (HPT) logging and Spectral Acoustics (SA) measurements to evaluate cluster performance, combined with thermo-hydrodynamic modeling. HPT detects minute temperature variations from fluid inflow, while Spectral Acoustic logging captures acoustic signatures of fluid movement into the wellbore. These logs are acquired via coiled tubing or tractor-conveyed tools to reach the lateral section. Data is collected under flowing conditions (often with a shut-in baseline) to identify temperature and acoustic-related anomalies at each cluster. A thermal-modeling software then matches the observed temperature profile by solving an inverse problem to estimate flow from each cluster. This process yields a quantitative flow profile along the wellbore, pinpointing the contribution of each perforation cluster. Field case studies show that HPT and SA diagnostics provide a detailed breakdown of flow from each cluster. For example, the combined measurements clearly differentiated contributing versus inactive fracture clusters along a shale well lateral. They also pinpoint zones of unwanted fluid entry (water or gas) from specific fractures, enabling targeted remediation. Conventional methods (spinner logs, fiber-optic DAS/DTS) often miss low-rate flows or provide only qualitative insight (Ugueto et al., 2016). In contrast, the HPT-SA approach quantified even subtle inflows, allowing engineers to compare completion designs. The analysis enabled selection of an optimal cluster spacing and perforation scheme, which was applied in new wells. Subsequent wells with the refined design showed more uniform cluster contributions and improved production, validating the cluster-level evaluation approach. This methodology is unique in using high-resolution temperature and acoustic data to assess fracture inflows on a fine scale. The combination of HPT and spectral acoustics offers an extended radius of investigation and improved vertical resolution, capturing behind-casing flows that conventional logs overlook. Unlike standard production logs that only measure inside the pipe, HPT-SA logs interpret thermal and acoustic signatures in the near-wellbore formation, yielding a much more accurate inflow distribution per cluster. These precise insights into each fracture's contribution enable completion engineers to optimize stage and cluster designs with greater confidence. Overall, this approach provides a step-change in fracture diagnostics, allowing clearer insight into each cluster's production contribution and guiding more effective field development.