Abstract:

With the increasing difficulty of tapping the remaining oil potential in domestic onshore old oil fields, traditional layered water injection technology has shown a series of problems such as low measurement and adjustment efficiency, poor accuracy, frequent downhole operations, and high production costs. It can no longer further improve the oil displacement effect and achieve the strategic goal of fine water injection. To address this issue, an evaluation was conducted on the practical application of intelligent water injection wells in low-permeability oil fields, and a new method was proposed to analyze the wellbore and reservoir status using intelligent layered water injection technology. Through on-site experimental research on intelligent injection wells in low-permeability blocks of oil fields, it had been verified that for layered injection wells in sections 3—7, the measurement and adjustment accuracy of layered flow rate was better than 5%, the adjustment time was 30—60min, and the operating cost was about 2000CNY, which was 1/6, 1/30, and 1/10 of traditional processes, respectively. This achieved refined management of reservoir water injection, reduced production costs, and significantly improved water injection efficiency and crude oil recovery rate. Moreover, relying on intelligent water injection wells, real-time monitoring of reservoir parameters could be achieved. For low-permeability reservoirs, effective single-layer indicator curves could be recorded within 10min, and effective reservoir pressure recovery curves could be recorded within 5h. Compared with traditional processes, this improved the efficiency and quality of data recording. Based on this, the injection production plan, reservoir status, and implementation measures could be effectively evaluated to meet the needs of reservoir analysis and provide new ideas for the development of intelligent layered water injection technology.

Key words: intelligent water injection well, low-permeability oil field, layered traffic allocation, pressure drop curve, characteristic curve

摘要：

随着国内陆上老油田剩余油挖潜难度不断增大，传统分层注水技术表现出测调效率低、精度差、下井作业频繁、生产成本高等一系列问题，已经不能达到进一步改善驱油效果、实现精细注水的战略目标。为了解决这一问题，本文对智能注水井在低渗透油田应用实践效果进行评价，并提出了利用智能分层注水技术分析井筒及储层状态的新方法。通过在油田低渗透区块智能注入井上进行现场试验研究，验证了对于3~7段的分层注入井，分层流量测量及调节精度优于5%、调节时间30~60min、操作成本约2000CNY，分别为传统工艺的1/6、1/30和1/10，实现了对储层注水的精细化管理，降低了生产成本且显著提高了注水效率和原油采收率。不仅如此，依托智能注水井可以实现储层参数实时监测，其中低渗透储层可在10min内录取有效的单层指示曲线，在5h内录取有效的关层压力恢复曲线；相比于传统工艺，提高了数据录取效率和质量，依此可对注采方案、储层状态和实施措施效果进行有效评价，以满足油藏分析的需求，为智能分层注水技术的发展提供了新思路。

关键词: 智能注水井, 低渗透油田, 分层流量调配, 压力降落曲线, 特征曲线