Storage Capacity of Geothermal Resources in Gaoling Group over the Eastern Half of Xi’an Depression

Weighted element method is proposed in this paper to improve the accuracy of calculating storage capacity of geothermal reservoirs. By making full use of all geothermal wells in the calculation region，this method had been proposed by the author in 2011,which is defined by every three neighboring geothermal wells. The calculation region is divided into many calculation elements. As a result, the entire calculation region of the distribution parameters is discretized into independent in each element with lumped parameters. The arithmetic mean of three-node parameters in each element is used as the lumped parameter, and the block with the same set of parameters is divided into calculation regions as small as possible. The effect of one element as well as its parameters in the entire.Calculation region depends on the weight of the area of this element in the whole calculation area. The weighted element method can be used to calculate the volumetric water storage capacity of geothermal fluids, elastic release storage capacity, geothermal storage capacity of volume water, geothermal energy storage capacity of elastic releasing water, geothermal storage capacity of geothermal reservoir rocks for each element, respectively. The storage capacities of various elements and the entire calculation regions can be calculated with superposition. The proposed approach was used to calculate the storage capacity of geothermal resources in Gaoling Formation of Xi’an Depression, in which data of 57 existing geothermal wells were available. If the geothermal energy recovery is set at 10% and the exploitation remains stable, the geothermal energy contained in the geothermal reservoir can be extracted for more than 7,000 years. Under the current conditions of exploitation technology, the actual geothermal energy that can be effectively exploited and used is 1915.6025×109kcal, which is equivalent to standard coal of 27.36575×104t.