渤海湾盆地北部新近系馆陶组地热田特征及开发实践——以河北省唐山市曹妃甸地热供暖项目为例

Geology and development of geothermal field in Neogene Guantao Formation in northern Bohai Bay Basin:A case of the Caofeidian geothermal heating project in Tangshan,China

选取渤海湾盆地南堡凹陷高尚堡-柳赞地热田为研究对象,系统探讨了研究区馆陶组地热资源地质条件与地热资源潜力,并介绍了曹妃甸地热能供暖的开发实践。研究表明,研究区馆陶组平均埋深1 500~2 500 m,岩性以砂砾岩为主,热储厚度平均为120~300 m,热储平均孔隙度28%~35%,渗透率(600~2 000)×10^(-3)μm^(2),热储温度70~110℃。地热资源量为13.79×10^(18)J,折合标准煤4.70×10^(8)t。利用以往油气勘探开发积累的大量地震、钻井资料,开展地热供暖开发目标选区、砂岩热储模拟和同层采灌技术试验,采用分散式采灌布井方式建设曹妃甸新城230×10^(4)m^(2)地热供暖试验项目,自2018年项目完成建设以来平稳运行两个供暖季,年均节约标准煤6.06×10^(4) t,减排二氧化碳15.87×10^(4)t,取得了良好的经济效益和社会效益。曹妃甸地热供暖试验项目证实了东部地区新近系砂岩热储利用同层采灌均衡技术可实现持续规模开发,为中国东部含油气盆地地热资源勘探和开发提供了有效借鉴。

Taking the Gaoshangpu-Liuzan geothermal field in the Nanpu sag of the Bohai Bay Basin as the research object,this paper discusses the geological conditions and potential of the geothermal resources of the Guantao Formation in the study area,and introduces the development practice of geothermal energy heating in Caofeidian.The average buried depth of the Guantao Formation is 1500-2500 m,the lithology is dominated by sandy conglomerate,and the average thickness of thermal reservoir is 120-300 m.The average porosity of thermal reservoir is 28%-35%,the permeability is(600-2000)×10^(-3)μm^(2),and the temperature of thermal reservoir is 70-110℃.The formation has total geothermal resources of 13.79×1018 J,equivalent to 4.70×10^(8) t of standard coal.Based on a large amount of seismic and drilling data from oil and gas exploration,this study carried out high quality target area selection,simulation of sandstone thermal reservoir,and production and injection in the same layer.The geothermal heating project with distributed production and injection well pattern covering an area of 230×10^(4) m^(2) was completed in the new district of Caofeidian in 2018.The project has been running steadily for two heating seasons,with an average annual saving of 6.06×10^(4) t of standard coal and a reduction of 15.87×10^(4) t of carbon dioxide,achieving good economic and social benefits.This project has proved that the Neogene sandstone geothermal reservoir in eastern China can achieve sustainable large-scale development by using the technology of"balanced production and injection in the same layer".It provides effective reference for the exploration and development of geothermal resource in oil and gas-bearing basins in eastern China.