Method of mapping reservoir fluid movement using gravity sensors

Patent metadata

Field	Value
Publication number	US-9651708-B2
Application number	US-201213449788-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Apr 21, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

The present disclosure relates to methods and apparatuses for acquiring multi-component gravity information for an earth formation. More particularly, the present disclosure relates to estimating the movement of fluid in an earth formation using at least one gravimeter configured to generate multi-component gravity information. The method may include estimating density changes in the earth formation. The method may include estimating a position of the at least one gravimeter. The apparatus may include a multi-component gravimeter configured to estimate gravity vectors for each vector component.

First claim

We claim:

1. A method of acquiring gravity information for an earth formation, the method comprising:
acquiring the gravity information for the earth formation using at least one gravimeter, the at least one gravimeter being configured to generate multi-component gravity information wherein the multi-component gravimeter information includes discrete estimates for gravity in three-dimensions, wherein each discrete estimate comprises a vector component including a magnitude and a direction, comprising:
generating signals with the at least one gravimeter corresponding to gravitational acceleration from each of the vector components of gravity in the earth formation; and
converting the signals into the multi-component gravitational information; and
estimating a change in a property of the earth formation based, at least in part, on discrete differences in the vector components of the multi-component gravity information over time, where the property includes at least one of: i) density and ii) total mass;
estimating fluid movement using the estimated change in the property;
using the estimated fluid movement for reservoir monitoring of a reservoir in the earth formation; and
performing at least one of: i) using the estimated change for drilling a borehole in the earth formation; and ii) using the estimated change to optimize recovery of at least one hydrocarbon from the earth formation.

2. The method of claim 1 , wherein the change in the property is estimated using an algorithm, wherein the algorithm includes at least one of: i) an inversion equation and ii) a forward modeling equation.

3. The method of claim 1 , the at least one gravimeter being disposed in a borehole penetrating the earth formation.

4. The method of claim 1 , wherein the multi-component gravity information includes vertical and horizontal gravity components of gravitational acceleration.

5. The method of claim 1 , further comprising:
modifying the multi-component gravity information to compensate for at least one known natural phenomenon.

6. The method of claim 1 , wherein the at least one gravimeter includes at least one of: i) a first multi-component gravimeter in the at least one borehole penetrating the earth formation at a first depth and a second multi-component gravimeter in the at least one borehole at a second depth and ii) a first multi-component gravimeter in a first borehole and a second multi-component gravimeter in a second borehole where the at least one borehole comprises the first borehole and the second borehole.

7. The method of claim 6 , wherein the first depth is a surface of the earth.

8. The method of claim 1 , wherein the at least one gravimeter comprises at least one vector gravimeter, and wherein the at least one vector gravimeter comprises at least three single axis gravimeters having linearly independent orientations.

9. The method of claim 1 , further comprising: transforming the multi-component gravity information from a local coordinate system of the at least one gravimeter to a global reference coordinate system, wherein the local coordinate system includes three-dimensions and the global reference coordinate system includes three-dimensions.

10. The method of claim 1 , further comprising:
modeling a volume of interest of the formation as a set of voxels;
using the multi-component gravitational information to estimate a change of the property of each voxel of the set; and
depicting the estimated change of the property of the voxels as an image of the volume of interest.

11. An apparatus for acquiring gravity information for an earth formation, the apparatus comprising:
at least one gravimeter configured to generate multi-component gravity information for the earth formation wherein the multi-component gravimeter information includes discrete estimates for gravity in three-dimensions, wherein each discrete estimate comprises a vector component including a magnitude and a direction, the at least one gravimeter configured to:
generate signals with the at least one gravimeter corresponding to gravitational acceleration from each of the vector components of gravity in the earth formation; and
convert the signals into the multi-component gravitational information;

and at least one processor configured to:
estimate a change in a property of the earth formation based, at least in part, on discrete differences in the vector components of the multi-component gravity information over time, where the property includes at least one of: i) density and ii) total mass;
estimate fluid movement using the estimated change in the property;
use the estimated fluid movement for reservoir monitoring of a reservoir in the earth formation; and
perform at least one of: i) using the estimated change for drilling a borehole in the earth formation; and ii) using the estimated change to optimize recovery of at least one hydrocarbon from the earth formation.

12. The apparatus of claim 11 , further comprising:
estimating the change in the property using an algorithm, wherein the algorithm includes at least one of: i) an inversion equation and ii) a forward modeling equation; and
providing a map of fluid distribution generated from the estimated change.

13. The apparatus of claim 11 , the at least one gravimeter being disposed in a borehole penetrating the earth formation.

14. The apparatus of claim 11 , wherein the at least one gravimeter is configured to estimate values of vertical and horizontal gravity components of gravitational acceleration.

15. The apparatus of claim 11 , the processor Maher configured to:
modify the multi-component gravity information to compensate for at least one known natural phenomenon.

16. The apparatus of claim 11 , wherein the at least one gravimeter includes at least one of: i) a first multi-component gravimeter in the at least one borehole penetrating the earth formation at a first depth and a second multi-component gravimeter in the at least one borehole at a second depth and ii) a first multi-component gravimeter in a first borehole and a second multi-component gravimeter in a second borehole where the at least one borehole comprises the first borehole and the second borehole.

Assignees

• Edwards Carl M
• Loermans Antonius M
• Baker Hughes Inc

Inventors

• Edwards Carl M
• Loermans Antonius M

Classifications

• G01V2210/622

  Velocity, density or impedance · CPC title

• G01V7/00 Primary

  Measuring gravitational fields or waves; Gravimetric prospecting or detecting · CPC title

• G01V7/06 Primary

  Analysis or interpretation of gravimetric records · CPC title