Assessing downhole WBM-contaminated connate water

Details Assessing downhole WBM-contaminated connate water Assessing downhole WBM-contaminated connate water

2006-04-18

2006-04-18

Thompson, Kenn (Department: 3672)

Wells

Processes

With indicating, testing, measuring or locating

C166S264000, C250S255000, C250S259000

Reexamination Certificate

active

07028773

ABSTRACT:
Water-based mud filtrate concentration in a downhole fluid sample drawn from the borehole of an oil well is assessed. To measure water-based mud filtrate concentration, a water-based mud having a water-soluble fluorescent dye tracer is pumped into the borehole; sample fluid from a selected downhole location is pumped through a downhole flow line having a window; sample fluid flowing in an excitation region of the downhole flow line is illuminated through the window with fluorescence excitation light; and fluorescence emission from the excitation region is measured to produce a measured value. The measured value represents the fraction of water-based mud filtrate in the sample fluid. A calibration value is determined representing 100% water-based mud filtrate. A method for validating a sample of connate water as having an acceptably low WBM filtrate contamination tests for validation downhole, in real time. Each measured value of the series of measured values is compared with a predetermined fraction of a calibration value. Samples that are validated may be captured and brought to the surface for analysis. A method using the time series data and a predetermined fraction of the calibration value calculates a predicted flushing time to completion.

REFERENCES:
patent: 3780575 (1973-12-01), Urbanosky
patent: 3859851 (1975-01-01), Urbanosky
patent: 4716973 (1988-01-01), Cobern
patent: 4860581 (1989-08-01), Zimmerman et al.
patent: 4994671 (1991-02-01), Safinya et al.
patent: 5167149 (1992-12-01), Mullins et al.
patent: 5335542 (1994-08-01), Ramakrishnan et al.
patent: 5939717 (1999-08-01), Mullins
patent: 6274865 (2001-08-01), Schroer et al.
patent: 6564866 (2003-05-01), Clark et al.
patent: 6645769 (2003-11-01), Tayebi et al.
patent: 6714872 (2004-03-01), DiFoggio et al.
patent: 6729400 (2004-05-01), Mullins et al.
Downare, T. D. et al. “Visible and Near-Infrared Fluorescence of Crude Oils”.Applied Spectroscopy, vol. 49, No. 6, (1995), pp. 754-764.
Mullins, O. C. et al. “Downhole Determination of GOR on Single-Phase Fluids by Optical Spectroscopy”.SPWLA 42nd Annual Symposium, Paper M, (2001), pp. 1-14.
Ralston, C. Y. et al. “Quantum Yields of Crude Oils”.Applied Spectroscopy, vol. 50, No. 12, (1996), pp. 1563-1568.
Wang, X. et al. “Fluorescence Lifetime Studies of Crude Oils”.Applied Spectroscopy, vol. 48, No. 8, (1994), pp. 977-984.

Affiliated with

Also associated with

Rating

Assessing downhole WBM-contaminated connate water does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Assessing downhole WBM-contaminated connate water, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Assessing downhole WBM-contaminated connate water will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3609001