中国石油网消息：二氧化碳埋入地下，如何确保封存通道长期安全？长庆油田给出了答案。3月初，长庆油田自主设计的井下腐蚀连续监测技术在现场试验中取得成功。该技术首次实现对CCUS（二氧化碳捕集、利用与封存）井筒腐蚀状况的长期原位监测，并配套形成带压测试工艺，为二氧化碳安全封装配置了“全天候传感器”。

China Oil News: How to ensure the long-term safety of the sealing channels when burying carbon dioxide underground? Changqing Oilfield has provided the answer. In early March, the underground corrosion continuous monitoring technology independently designed by Changqing Oilfield achieved success in on-site experiments. This technology was the first to realize long-term in-situ monitoring of the corrosion condition of CCUS (carbon dioxide capture, utilization and storage) wellbores, and was also equipped with a pressure-bearing testing process, providing "all-weather sensors" for the safe encapsulation of carbon dioxide.

　　近年来，随着CCUS技术的加快应用，一个关键难题浮出水面：在气水交替、超临界等复杂工况下，二氧化碳因其极强的溶解与渗透能力，可使井筒腐蚀速率达到常规环境的5~10倍。作为二氧化碳注入与封存的唯一通道，井筒的完整性直接关系到埋存安全。然而，传统监测手段却难以满足这一需求。

In recent years, with the accelerated application of CCUS technology, a key problem has emerged: in complex conditions such as gas-water alternation and supercritical state, due to its extremely strong solubility and permeability, carbon dioxide can cause the corrosion rate of the wellbore to reach 5 to 10 times that of the conventional environment. As the sole channel for carbon dioxide injection and storage, the integrity of the wellbore directly affects the safety of storage. However, traditional monitoring methods are unable to meet this demand.

　　当前常用的监测方式主要依赖腐蚀挂片，即将金属片下入井中，数月后取出检测。这种方法不仅数据获取周期长、监测信息严重滞后，只能在腐蚀损伤发生后被动补救，还无法实时捕捉工况变化对腐蚀趋势的瞬时影响，导致防腐方案难以精准优化，极大制约了CCUS技术的效果评估与规模化推广进程。

The current commonly used monitoring methods mainly rely on corrosion coupons, where metal coupons are lowered into the well and retrieved for testing after several months. This method not only has a long data acquisition cycle and severely delayed monitoring information, but also can only respond passively after corrosion damage occurs. It is unable to capture the instantaneous impact of operational conditions changes on the corrosion trend, making it difficult to precisely optimize the anti-corrosion plan and greatly restricting the effectiveness eva luation and large-scale promotion process of CCUS technology.

　　为此，长庆油田技术团队历时3年攻关，锚定“多参数感应、数据传输”的研究方向，自主设计出井下电感探针腐蚀监测装置。

To achieve this, the technical team of Changqing Oilfield spent three years conducting research and development, focusing on the research direction of "multiple parameter induction and data transmission", and independently designed an underground electrical induction probe corrosion monitoring device.

该装置采用“电感探针+腐蚀挂片”相结合的复合监测模式，通过向金属试片施加电流信号，实时捕捉腐蚀引起的电阻变化，并转换为电信号，从而精确追踪金属减薄过程。

This device adopts a combined monitoring mode of "inductive probe + corrosion coupon", by applying an electric current signal to the metal test piece, it can promptly capture the resistance changes caused by corrosion and convert them into electrical signals, thereby accurately tracking the metal thinning process.

测试显示，其测量精度达到30微米，误差率小于10%，相当于将实验室级别的检测能力延伸至数千米井下。“井下环境高温、高压、强腐蚀。我们研制的这套‘眼睛’，能够耐温125摄氏度、承压60兆帕，从而保证在油水介质中长期稳定工作。”油气工艺研究院油田化学与防腐研究所副所长郭钢说。

The test results show that the measurement accuracy reaches 30 micrometers, with an error rate of less than 10%. This is equivalent to extending the laboratory-level detection capability to thousands of meters underground. "The underground environment is extremely hot, high-pressure and highly corrosive. The 'eyes' we have developed can withstand temperatures of 125 degrees Celsius and pressures of 60 megapascals, thus ensuring long-term stable operation in oil and water media," said Guo Gang, deputy director of the Oilfield Chemistry and Corrosion Research Institute of the Oil and Gas Process Technology Research Institute.

　　为适应井下苛刻工况，技术团队反复优化结构设计：采用厚壁圆筒力学模型，安全系数达4.44，远超1.3的工程设计标准；两道O形密封环确保滴水不漏；低功耗设计让设备在24小时采集一次的频率下，续航长达10个月。目前，该技术已从实验室走向井场，经受住了实战检验。

To adapt to the harsh working conditions underground, the technical team repeatedly optimized the structural design: they adopted a thick-walled cylindrical mechanical model, with a safety factor of 4.44, far exceeding the engineering design standard of 1.3; two O-ring seals ensure no water leakage; the low-power design enables the equipment to operate for up to 10 months at a frequency of collecting data once every 24 hours. Currently, this technology has moved from the laboratory to the well site and has withstood practical tests.

“截至目前，该技术已在13口井开展现场试验，一次下入成功率达100%，数据传输稳定可靠。”郭钢介绍。依据监测结果，长庆油田已调整区块方案3批次，优化节约防腐费用近千万元。这项技术的突破不仅大幅降低了运维成本，更实现了井下腐蚀监测从“事后分析”到“实时监护”的跨越，为管材寿命预测和防腐策略优化提供了精准的数据支撑，也为CCUS规模化应用扫清了障碍。下一步，技术团队将努力实现腐蚀数据从“地下存储、起出读取”向“实时在线传输”的升级。

"As of now, this technology has been tested in 13 wells on-site. The success rate of a single insertion has reached 100%, and the data transmission is stable and reliable." Guo Gang explained. Based on the monitoring results, the Changqing Oilfield has adjusted the block plans 3 times, optimizing and saving over 10 million yuan in anti-corrosion costs. This technological breakthrough not only significantly reduces operation and maintenance costs, but also achieves a leap from "post-event analysis" to "real-time monitoring" in downhole corrosion monitoring, providing precise data support for pipe material life prediction and anti-corrosion strategy optimization, and clearing the way for the large-scale application of CCUS. In the future, the technical team will strive to upgrade the corrosion data from "storage underground and retrieva l after extraction" to "real-time online transmission".