Characterizing oil, gasor geothermal wells, including fractures thereof
US6724687B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 26, 2000 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Jan 12, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF24S2201/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An excitation event in an oil, gas or geothermal well creates a responsive signal having lower and higher frequency components, which higher frequency component provides information about one or more characteristics of the well. Examples of such characteristics pertaining to a subterranean fracture include: breakdown pressure at fracture initiation, time it takes proppant to reach and to screenout the tip of the fracture, fracture geometry and fracture growth, fracture closure pressure, relative fluid flow through respective perforations, and horsepower requirements to perform a fracture treatment. One excitation event includes creating an excitation signal having a maximum amplitude change occurring within a time t1, which is less than a period t2 of the higher frequency component. Wavelet processing may be used to separate or distinguish the higher frequency waveform from the lower frequency waveform. The information can be used to control a process (for example, a fracturing process) applied to the respective well or one or more other wells. In another aspect, an unidentified signature waveform is compared to identified signature waveforms in a neural network computer database t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.