Permanent Outer-casing Fiber Optic Monitoring Technology:This technology involves placing the fiber optic cable outside the casing and lowering it into the well. In the horizontal section, a Magnetic Orientation Tool (MOT) and a directional perforating tool are used to avoid interference. The continuous coiled tubing conveyed fracturing process is used to implement segmented sand fracturing.During the fracturing process, the fiber optic cable continuously monitors the fluid intake and proppant injection volumes for each fracturing cluster in the horizontal section, allowing evaluation of the performance of each fracturing stage.After production starts, the fiber optic cable periodically collects temperature, acoustics, and pressure data, which are used to interpret the production performance of each zone and provide a reliable basis for optimizing the parameters.

Scope of application:

Well types suitable for cased-hole completions.

Characteristics and advantages：

Optical fibers installed externally to the casing do not obstruct fluid flow within the casing or disrupt flow patterns, and do not impact the installation of packers, safety valves, and tubing.

The use of magnetic orientation (MOT) logging tools and oriented perforating does not impact future field development.

Real-time monitoring of the hydraulic fracturing process in oil and gas wells, on-site evaluation of fracture stimulation effectiveness, and optimization of the fracturing program.

Through distributed fiber optic fracture monitoring, the evaluation of individual cluster performance can be conducted, while also enabling the monitoring of inter-stage and inter-well interference.

Through downhole monitoring of the hydraulic fracturing process in the treated well, extraneous interference factors can be eliminated, resulting in more accurate monitoring results.

 Through the deployment of fiber optics within the wellbore, horizontal well sections with inter-stage spacing up to 600 meters can be monitored during the hydraulic fracturing process.

Periodically monitoring the production profile and static/flowing pressure data during the production process, in order to evaluate the production contribution of individual pay zones and the corresponding reservoir characteristics.

Automatically analyzing the monitoring data to timely detect and provide early warning of potential production anomalies or safety hazards, such as leaks, cross-flow between zones, etc.

Application situation：

Here is the translation using petroleum industry terminology:

The permanently installed outer casing fiber optic monitoring technology has been applied in multiple oil and gas fields in regions like Changqing and Xinjiang, and has achieved significant results. These applications have not only improved the efficiency and safety of oil and gas development, but also provided important support for driving the digitalization and smart transformation of the oil and gas industry.Changqing Outer Casing Fiber Optic Monitoring:Through the outer casing fiber optic monitoring, the system can conduct real-time monitoring of the fluid and proppant injection rates for each fracture cluster during the multi-stage hydraulic fracturing of a horizontal well. This allows for the evaluation of the fracturing performance in each interval.

 Fracture Monitoring and Analysis:The monitoring frequency range is 1-150 Hz. The signal is strongest at the first stage location. The second and fourth stages showed consistent signals throughout the fracturing process. Some signals were detected in the third and fifth stages during the later part of the fracturing.The DTS (Distributed Temperature Sensing) monitoring recorded the largest temperature drop at the first stage sleeve position, indicating the fracturing effectiveness was better in the first, second, and fourth stages.

After 3 test cycles, the monitoring detected clear noise signals at the first and second stage sleeve locations, indicating the packer may have experienced some leakage.