| 摘要 |
<p>The invention relates to an improved composition, to the preparation and to the application of a foamed, oil-based ultra-light drilling fluid, with half-lives of greater than 10 hours, for drilling in depression oil fields where there are argillaceous bodies that are active and brittle and also exhibit temperatures above 180°C. The ultra-light fluid is resistant to contamination from salt water, crude oil, sour gases, cement and drilling cuttings. This fluid can be used for drilling, repairing and finishing wells using the Underbalanced Drilling or Managed Pressure Drilling methods or the traditional drilling method using a gas (nitrogen, air, among others). It uses a foam generator and/or a diffuser individually or in combination to reduce the specific gravity of the fluid to values below 0.2 and can be pumped into the well. A novel aspect of the invention is that the stability of the fluid is improved by being subjected to the effects of temperature and can be pumped into the well without cavitation problems through the use of a disk pump connected to the suction end of the mud pumps.</p> |
