| 摘要 |
<p>A formation surrounding an underground boring is treated by (1) hydraulic fracturing by injection of a liquid at a rate and a pressure to develop the fracture, stopping the injection, and repeating the injection, followed by (2) injection of a supplementary liquid contg. abrasive particles; the particles are introduced periodically, first at a predetermined concn. and then at a higher concn. The boring is flushed with a liquid at least after the injection of the abrasive material. A low-viscosity fluid, esp. water, is used for the fracturing, water being cheap and safe. Low-viscosity fluids enter the formation laterally, rather than vertically. Movement through the fracture is greatly increased by the periodical injection of the abrasive. A permeability of 1,000,000 millidarcy can be achieved even in soft formation. The process is esp. useful in wells which contain a very mobile solid which tends to block the fractures; this solid is removed by the low-viscosity fluid.</p> |
