| 摘要 |
<p>The invention pertains to a method to hinder/reduce migration of formation fluids in wells, primarily in connection with plugging of wells. A preferably poorly sorted particulate matter consisting of naturally occurring and/or synthetically produced granular material, eventually such material suspended in a suitable liquid, is placed in or around remaining casings (10, 12, 14 and 16) and production tubing (28), and eventual other remaining equipment, in all or in portions of the well. The particulate material mentioned can replace, eventually be utilised in combinations with, conventional mechanical plugs (40, 44, 48) and cement plugs (42, 46, 50). The particulate material plug (52) must over a sufficient length in the well be suitably sorted, packed and eventually be provided with preferable chemical/physical properties, such that the permeability of the plug (52) becomes sufficiently small. This results in that the time required for formation fluids to migrate through may become several thousand years. The plug of particulate matter (52) can also change in shape and adapt to eventual geometry changes in the well, for example as a consequence of displacements in the Earth's crust or corrosion of metals in the well, and thereby hinder/minimise eventual leaks.</p> |
