Electrical resisitivity measurements of brine saturated porous media near211 reservoir conditions: Awibengkok preliminary results

摘要

Laboratory measurements of the electrical resistivity of rocks and synthetic211u001erocks with confining pressures up to 100 bars and temperatures between 20 and 211u001e211DGC were performed to further investigate how the pore-size distribution and 211u001ecapillarity affects boiling in porous media. Similar to previous measurements on 211u001esamples from The Geysers, CA, we observed a gradual increase in resistivity when 211u001epore pressure was decreased below the phase-boundary pressure of free water, an 211u001eindication that boiling is controlled not only by temperature and pressure, but 211u001ealso by pore size distribution. Other important phenomena observed were strong 211u001eresistance fluctuations during boiling that may be chaotic, and salt deposition 211u001ethat caused sample cracking. If confirmed in further experiments, these results 211u001emay lead to a new geophysical diagnostic for locating boiling in high 211u001epermeability areas of geothermal reservoirs and for methods of permeability 211u001ealteration.