Test Analysis of Hydraulic Fracturing in Gaoyuzhuang Formation Carbonatite Reservoir in Cangxian Bulge Region
Abstract
There are abundant geothermal resources in North China Basin, which has multi-layer thermal reservoir from above to below. Thereinto, JxzGaoyuzhuang formation hermal reservoir exists in Jizhong depression and Cangxian Bulge Region widespreadly and potentially, but lies deeply with complex rock structure meanwhile. The reservoir space of the Gaoyuzhuang formation geothermal water is fracture-pore type or porous type with strong heterogeneity, which has restricts the large-scale development of the reservoir seriously. This paper analyses the hydraulic fracturing test of Gaoyuzhuang formation geothermal reservoir of GRY1 well in Beijing–Tianjin–Hebei scientific research base (Xian county), concluding that the water-absorbing capacity of the formation is 0.426-0.435m3/min/MPa, formation closure (fracture) average pressure is 38.8MPa, formation closure (rupture) pressure gradient is 0.0102MPa/m (abnormally low), surface closing pressure is 1.16MPa, liquid made sewing Effective probability is 16.2%, the fracture closes in 2.8 to 4.7min after stopping the pump, analyzing that formation filtration loss is large. In the test, formation liquild inflow quantity is 283m³, amount of sand is 2.3m³. Through the research of software simulation, the fracture length is 64.3m, height is 131.3m, width is 0.67cm, top and bottom range is 3787.5-3918.8m. The test results show that hydraulic fracturing is feasible in Gaoyuzhuang formation geothermal reservoir, and has a remarkable effect, meanwhile have been successfully realized the first demonstration project of EGS in China, which can provide reference for thermal reservoir reconstruction of the same kind in future.
