Method for determining the characteristics of a fluid-producing underground formation
US4597290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1984 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | Apr 19, 2004 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/008
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Disclosed is a method for determining the physical characteristics of a system made up of a well and an underground formation containing a fluid and communicating with the well. A change in the rate of flow of the fluid is produced and a measurement is made of a parameter characteristic of the pressure P of the fluid at successive time intervals .DELTA.t. One then compares PA1 on the one hand, the theoretical evolution of the logarithm of the derivative P'.sub.D of the dimensionless pressure as a function of the logarithm of t.sub.D /C.sub.D, the derivative P'.sub.D being with respect to t.sub.D /C.sub.D, t.sub.D representing the dimensionless time and C.sub.D the wellbore storage (compression or decompression) effect, with PA1 on the other hand, the experimental evolution of the logarithm of the derivative .DELTA.P' of the pressure as a function of the logarithm of the corresponding time intervals .DELTA.t, the derivative .DELTA.P' being with respect to time t. One then determines, from the comparison of said theoretical and experimental evolutions, the product kh of the permeability k by the thickness of said formation h, and the coefficient C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.