Research On Reconstruction Technology of Carbonate Thermal Reservoir

Under the background of China's efforts to promote the development of clean energy, strengthen the control of atmospheric haze and accelerate the development of geothermal resources, more and more heat users choose clean energy heating. Puyang Xinxing clean energy Co., Ltd. mainly focuses on carbonate thermal reservoirs in the area. At present, the company has invested more than 800 million yuan in Puyang City to build 25 geothermal station buildings, 57 carbonate thermal storage geothermal wells were drilled, with a heating capacity of 6.3 million square meters, covering 72 heating communities, bringing warmth to more than 60000 households. Due to the strong heterogeneity of carbonate thermal reservoir, some geothermal wells did not have large leakage during construction, resulting in low pumping capacity and insufficient formation liquid supply, which could not provide heat source guarantee for thermal users. The reasons are as follows: first, the fractures of the target layer are not fully developed and the water channel is narrow; 2、 In the process of geothermal well construction, lost circulation leads to the leakage of drilled cuttings and drilling fluid into the production layer cracks, blocking and polluting the water layer. Through multiple systematic analysis of data such as logging interpretation, logging cuttings description and drilling abnormalities in drilling construction, select rock cuttings in fractured reservoir for test comparison, determine the type of plugging removal fluid and transformation scheme, and constantly summarize experience in combination with field practical application cases. The final results show that under the condition of incomplete development of its own geological conditions, the carbonate thermal reservoir can achieve the purpose of increasing production through transformation, give full play to its maximum production capacity, realize the scientific utilization of "appropriate production and irrigation" and meet the sustainable operation of the project.