ANALYSIS OF THE EXPLOITATION OF EXISTING DEEP PRODUCTION WELLS FOR ACQIRING GEOTHERMAL ENERGY

摘要

The aim of the work is to assess the possibility and usefulness of acquiring geothermal energy from the existing production well Jachowka K-2. The initial assumptions that are essential for estimation of both a heat flux transferred between a deposit and a heat carrier and a heat flux permeated through the barrier are discussed. To achieve this goal, the authors have worked out a computational model that allowed them to determine the value of the gained geothermal heat flux using a double-pipe geothermal heat exchanger with a dead center. In what follows, the results of calculations of a heat flux that can be gained in the investigated well at a depth L = 2870 m are given. In most cases, geothermal heat plants operate in two-hole systems with injection and production wells. In such systems, the temperature of the geothermal water extracted to the earth's surface as well as the temperature of the water injected onto a deposit level may be estimated to sufficient accuracy with the help of the known computational models in a relatively simple way. When the flows of drawn-out water are great, changes in the temperature of geothermal water in injection and production conductors are relatively low. However, the high expenditure of hole drilling in comparison to the total capital cost is a negative aspect of using this method in acquiring thermal energy. Employment of a one-hole injection system may reduce the capital cost. Drilling of one hole or using existing single holes resulting from rock oil and earth gas extraction is the most effective from the economical point of view. To adapt the hole, a vertical exchanger with a double-pipe exchanger must be located in it. In this case, geothermal water is extracted with the inside pipe and injected into a deposit with a ring-shaped channel.