Abstract:

The Nanpu Sag in the Huanghua Depression of the Bohai Bay Basin is rich in geothermal resources, with multiple geothermal fields identified, including Gaoshangpu-Liuzan, Nanpu, and Matouying. The thermal reservoirs, primarily composed of fluvial sandstone from the Guantao Formation, exhibit advantages such as high temperatures（70-90 ℃）, significant water amounts (100 m³/h), large-scale reservoirs, and thick caprocks. However, their development faces several challenges, including optimal target area selection, sustainability evaluation, efficient drilling and production processes, reinjection into sandstone reservoirs, long-distance centralized thermal water transportation, and intelligent monitoring. To address these challenges, practical exploration in the Gaoshangpu-Liuzan geothermal field has led to the development of five core technologies: 1） optimization and detailed resource evaluation technology for exploration areas; 2） well placement and thermal field simulation technology; 3） geothermal well drilling, completion, and pressure-free reinjection for sandstone thermal reservoirs; 4） multi-well collection and long-distance thermal water transportation technology; 5） intelligent management and control technology for geothermal development. These advancements provide technical support for geothermal heating projects in the Gaoshangpu-Liuzan geothermal field and the geothermal development efforts of Jidong Oilfield.

Key words: Nanpu Sag, Gaoshangpu-Liuzan geothermal field, geothermal development and utilization, fluvial sandstone thermal reservoir, well flushing type