天津地区地热田热储层压力分析及研究意义

Due to long-term geothermal field development, the reservoir pressure dropping will result in the decline of water level. Through the continuous monitoring of water level depth and surface temperature, we can learn about the hydrodynamic status of geothermal field. At present, we can understand the status of geothermal field reservoir pressure and analysis the reservoir pressure only through real geophysical logging..For dynamic characteristics analysis and research of geothermal field, the hydrodynamic characteristics and water chemical characteristics study of geothermal field is main, the study of reservoir pressure variation law is not much, and the pressure calculation method research of reservoir is less. But in the process of geothermal resources evaluation of geothermal field, the reservoir pressure can show the reservoir potential and forecast the trend of the development of geothermal field and reservoir characteristics, it is better for us to plan the development and utilization of geothermal field using the reservoir pressure. Therefore, in the process of geothermal resources development and utilization of geothermal field, reservoir pressure analysis is very important, and it is of great significance for the research of reservoir pressure calculation..In addition to the on-site logging methods, the calculation of reservoir pressure only uses the summary experience formula, although the reservoir pressure can be calculated by dynamic monitoring data using this formula, by contrast, it is more different between the calculation results and the actual geophysical logging to the reservoir pressure. This article mainly studies the calculated methods and formula of reservoir pressure through the actual reservoir temperature and pressure of part real geophysical logging in order to fix the existing formula of reservoir pressure. .If we can modify the experience formula of the reservoir pressure and solve error cause according to the results of geophysical logging part of geothermal Wells, the results could reflect actual situation of the reservoir pressure using the modified calculation formula of reservoir pressure to calculate the reservoir pressure, it is very important guiding significance for the development of geothermal resources.

由于长期对地热田开发，热储压力下降导致水位埋深下降，为了解地热田热储压力现状，只有通过物探测井方式。.开展对地热田的动态监测分析研究时，主要研究热储的水动力场特征，水化学特征等，而对热储压力变化规律的研究不多，对热储压力计算方法研究的更少。.除进行现场测井外方法外，目前对热储压力的计算仅仅利用总结的经验公式，该公式虽然能通过动态监测数据计算热储压力，但是通过对比分析，计算结果与实际测到的热储压力相差比较大。本项研究拟通过物探测井实际测试的热储温度和热储压力的数据，对热储压力计算方法和公式进行分析研究，修改现有的热储压力计算公式。如果能根据部分地热井的物探测井结果，对热储压力的经验公式进行修正并解决造成误差的原因，采用修改后计算公式，进行热储压力计算，得到的结果切实符合热储层的实际压力，对开发地热资源具体重要的指导意义。

选取DL-48，DL-48B，DL-40地热井作为典型地热井，进行了热储压力测试和连续测温，测试数据完成，地热井热储均为雾迷山组热储，地层资料完整，成井结构清晰，测试时间和数据采集满足计划要求，数据取值间隔为0.125m一个数据采集点，便于测试数据的拟合，利于热储压力计算方程的建立。.雾迷山组热储是天津市东丽湖地区主要开发利用热储层，结合多年开采、回灌动态监测数据和地热井压力测试数据，对地热回灌条件下雾迷山组热储的水动力（压力）场变化特征进行分析，分别从热储层压力平面特征、垂向特征的变化研究回灌对于储层压力变化的影响，探讨回灌对于热储层的压力场变化作用的特点及对热储下降趋势的缓解效果，可为天津雾迷山组的热储未来地热回灌发展提供依据。.根据井底压力测试和连续测温数据分析，压力随地热井深度的增加而增加，呈现线性相关关系；温度随地热井深度的增加而增加，呈现线性相关的关系，并因为地层的不同而发生微小的变化。.对数据分析来看，依据传统的计算公式计算的得到热储压力比实际测到的压力小，一般小1MPa，将热储温度随深度进行连续变化融入计算中，计算的热储压力比实际测到小0.1-0.3MPa，目前继续进行其他地热井的井底压力和连续测温数据进行了数据拟合和研究。.总体上来说，通过分析地热井多年水位动态观测数据、测温测压数据等相关资料，认为回灌对热储压力场的恢复有一定的作用。鉴于此，今后需进一步加大回灌力度，以期在未来能有效地缓解热储层压力下降的趋势，使地热能这一优质资源得以可持续开发利用。项目成果将在地热资源动态监测，地热资源回灌研究等方面具有应用前景。