中深层砂岩热储回灌井参数优化模拟

砂岩热储回灌对于地热能源的高效利用和土壤环境的保护具有重要的意义。华北地区中深层孔隙型砂岩地热回灌效率低下,回灌参数优化不准确,需要对中深层砂岩热储回灌井参数进一步优化研究,提升回灌效率。因此开展有关中深层砂岩热储回灌井参数优化模拟的研究尤为重要。建立了基于CMG-STARS的华北地区砂岩热储定向井的回灌与采出模型,分别研究了完井方式、单日回灌量、水层厚度比及采灌井径对地热回灌效率的影响,并分析优化中深层砂岩热储的回灌井参数。结果表明：完井方式是影响回灌效率的最主要因素,依次是单日回灌量、采灌井井径、水层厚度。为提高回灌效率,通过模拟研究优选出参数方案为表皮系数的最佳数值为0和5,单日回灌量在1 600 m³左右,采灌井径为215.9～241.3 mm,水层厚度比为0.33～1。结合造井成本因素,采灌井型选用“一定向井”回灌“一定向井”生产模式,其回灌效率明显高于“一定向井”回灌“一直井”生产模式。

Simulation study on parameters optimization of middle deep sandstone heat storage and recharge wells

Sandstone heat storage and recharge play an important role in efficient utilization of geothermal energy and soil environment protection. The geothermal recharge efficiency of middle and deep pore sandstone in North China is low and the recharge parameters are not optimized accurately. It is necessary to further optimize the recharge well parameters of middle and deep sandstone heat storage to improve the recharge efficiency. Therefore, it is very important to study the parameter optimization simulation of middle deep sandstone heat storage and recharge Wells. In this paper, the recharge and recovery model of directional Wells for sandstone heat storage in North China is established based on CMG-STARS. The effects of well completion mode, single-day recharge amount, water layer thickness ratio and well diameter on geothermal recharge efficiency are studied respectively, and the recharge well parameters for middle and deep sandstone heat storage are analyzed and optimized. The results show that the completion mode is the most important factor affecting the injection efficiency, which is followed by one-day injection volume, well diameter and water layer thickness. In order to improve the recharge efficiency, the optimal parameters of skin coefficient are 0 and 5, the daily recharge volume is about 1600m3, the well diameter is 215.9mm~241.3mm, and the water layer thickness ratio is 0.33~1. Combined with the factors of well construction cost, the production mode of "one directional well" and "one directional well" is selected for the production mode of "one directional well" and "one directional well", and its recharge efficiency is obviously higher than that of "one directional well" and "all the way well".