Patent · US Expired

Method and apparatus for differentiating oil based mud filtrate from connate oil

US6107796A · kind A · utility

41Cited by
32References
34Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 17, 1998
Grant dateAug 22, 2000
Priority date
Expiry dateAug 17, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R33/4625
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method and apparatus for processing nuclear magnetic resonance (NMR) information to differentiate between oil based mud filtrate (OBM), and connate oils, during subsurface exploration. An NMR experiment is performed on a sample of formation fluid, and the resulting data is then processed to differentiate between the relaxation time parameters characteristic of OBMs and those characteristic of connate oils. A simple arithmetic difference between relaxation times calculated for successive samples may be followed by a distributional analysis performed in either the time domain or relaxation spectrum domain. The process is repeated for other fluid samples and the data for successive fluid samples is compared so that the user may determine when the formation fluid consists almost entirely of connate oil.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.