公开(公告)号：US20170285215A1

公开(公告)日：2017-10-05

申请号：US15472897

申请日：2017-03-29

Applicant: Chevron U.S.A. Inc.

Inventor： Haijing Wang ,  Boqin Sun ,  Scott J. Seltzer ,  John S. Zintsmaster ,  Hussein Alboudwarej

IPC: G01V3/32 ,  G01R33/46 ,  G01R33/31

CPC classification number: G01R33/46 ,  G01N24/081 ,  G01R33/305 ,  G01R33/31 ,  G01R33/448

Abstract: To measure the phase behavior of a fluid in a porous medium such as a tight gas shale, one illustrative method involves: (a) loading the fluid into a sample cell containing the porous medium; (b) setting a pressure and a temperature for the fluid in the sample cell; (c) applying an RF pulse sequence to the fluid in the sample cell to acquire an NMR signal; (d) deriving from the NMR signal an NMR parameter distribution that depends on the pressure and the temperature; (e) determining whether a fluid phase is present based on the NMR parameter distribution; (f) repeating operations (c) through (f) to determine the presence or absence of the fluid phase at multiple points along a pressure-temperature path that crosses a phase boundary; and (g) providing an estimated location of the phase boundary based on the presence or absence of the fluid phase at said points.