Abstract
Design and development of the large-scale geothermal HDR/ HWR reservoirs with the multiple-borehole circulation systems can be one of the effective engineering approaches for producing geothermal energy in big amounts, sufficient for further industrial utilization. The major factor that may affect the productivity of this large-scale geothermal reservoir is a proper geometrical arrangement of the multiple-borehole-circulation-system. The numerical simulator FRACSIM-3D is applied for defining the sufficient reservoir size and the relevant multiple-borehole system configurations. Based on the series of computations the efficient location of the production wells is proposed. Within the proposed well arrangement, the number of production wells can be effectively minimized without reduction of the reservoir total thermal output. Assuming a composite multi-unit structure of the reservoir as a hierarchical system, where the whole reservoir consists of a finite number of unites (each local unit has its symmetrically distributed system of injection and production wells), makes possible to reduce the total number of production wells by 55%. The latter was shown on the basis of the large-scale reservoir model with 9 tetragonal overlapped multi-unit systems. Numerical modeling of the composite reservoir constituted by 9 overlapped multiple-borehole units shows that this type of arrangement is more efficient comparing with 9 independent (non-overlapped) units. The flow rate from the production wells located in the overlapped regions of the multi-unit reservoir is higher than in the wells placed within the non-overlapped regions. Since during the stimulation stage the overlapped areas of the multi-unit reservoir are affected by several injection wells, they have higher fracture density than non-overlapped areas. For the multi-unit reservoir system, the total thermal output is almost proportional to the number of the reservoir units. Numerical simulations for the different multi-unit well configurations show that creation of large-scale geothermal reservoirs with effectively arranged multiple-borehole systems is a quite feasible method to enhance thermal performance of the reservoir.
| Original language | English |
|---|---|
| Pages (from-to) | 747-751 |
| Number of pages | 5 |
| Journal | Transactions - Geothermal Resources Council |
| Volume | 27 |
| Publication status | Published - 2003 |
| Event | International Collaboration for Geothermal Energy in the Americas - Geothermal Resources Counsil: 2003 Annual Meeting - Morelia, Michoacan, Mexico Duration: 2003 Oct 12 → 2003 Oct 15 |
Keywords
- Geothermal energy
- HDR
- Multi-unit geothermal system
- Multiple-borehole system
- Numerical simulation
