Case Study: Expanding Flow Diagnostics With Tubing-Conveyed Payload-Deployment Tool for Solid Fluid Tracer Delivery and Wellbore Cleanout

_ The rapid evolution of unconventional reservoirs and increasingly complex wellbore designs have enhanced the industry’s need for reliable and cost-effective methods to gather high-resolution flow data. Production diagnostics remain central to understanding reservoir performance, optimizing completion strategies, and aiding long-term field development. Yet, the techniques available to operators often involve costly upfront capex investments, limited data duration, or logistical challenges that restrict the quality and frequency of measurements. To address these issues, a new tubing-conveyed system called the payload-deployment tool (PDT) has been developed. The PDT (Fig. 1) introduces an innovative approach to long-term production diagnostics by combining wellbore-cleanout capabilities with the deployment of multiple solid water or oil tracer payloads in a single run. Designed for reentry into single and multilateral wells, the system provides a low-impact approach to generating long-term flow data across a broad range of well environments. The PDT enables production engineers and well-intervention teams to conduct their own diagnostic tests, comparable to completions teams, and compile key data sets for flow assurance and flow tracking for the remainder of a well’s life cycle. This case study outlines the motivation behind the tool’s development, describes its broad functionality, and presents results from a field trial in the Lower Wolfcamp B Formation within the Permian Basin. Industry Challenges in Flow Diagnostics For decades, operators have relied on a combination of downhole gauges, fiber optics, chemical tracers, and production logging to perform flow diagnostics. However, each method comes with tradeoffs. - Downhole gauges provide valuable pressure and temperature measurements, but they cannot directly distinguish between contributions from individual stages or laterals. - Fiber optics provide the highest resolution of distributed acoustic and temperature sensing, but the capex and overall probability of success are challenging to replicate on a day-to-day basis. - Liquid chemical tracers used in fracturing operations are proven but typically offer lifetimes of 3 to 6 months. Liquid tracers also face issues with adsorption and the accuracy of their delivery at the planned point in each fracture stage. Additionally, there is only one chance to perform these tracer operations during the initial fracture stimulation. - Production logging using wireline or coiled-tubing interventions can provide near-instantaneous data, but may not show a long enough data set. They are operationally complex, expensive, and usually infeasible in long-reach laterals. Adding to the complexity, most producing wells require artificial lift, which makes it impractical to run logging tools concurrently with the lift system. - Wellbore-integrity and flow-assurance issues such as sand production, scale buildup, or fracture-to-fracture communication events introduce further complications. A diagnostic method that also contributes to wellbore cleanup and flow assurance provides additional operational value. - As stage counts increase and compete for preferential flow, operators increasingly need downhole technologies that can be deployed efficiently to deliver stage-by-stage flow diagnostics.