Determination of downhole pressure while pumping
US7874362B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2007 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Apr 18, 2028 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Tubewaves are used to transmit an indication of the depth at which a condition is detected in a well. In particular, the depth is calculated based on the difference in arrival time at the surface of a first tubewave which propagates directly upward in the borehole and a second tubewave which initially travels downward and is then reflected upward. The tubewaves may be generated by a canister designed to implode at a certain pressure. The canister is carried downhole by gravity and the fluid being pumped. At a depth at which its pressure tolerance is exceeded, it implodes and generates the tubewaves. An analyzer at the surface detects the tubewaves and generates a pressure versus depth profile of the well. Canisters may be acoustically tagged in order to generate tubewaves having particular frequency and amplitude characteristics. Canisters may also be configured to produce multiple implosions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.