System and method for determining the relative permeability of an earth formation surrounding a wellbore

Claim 1

A method for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; measuring at different points in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasion into the earth formation at different points in time; and determining in response to said radii determinations the relative permeability of the earth formation.

Claim 2

A method for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; measuring at different points in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasion into the earth formation at different points in time; and determining in response to said radii determinations the relative permeability of the earth formation.

Claim 6

A system for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising: means for injecting a fluid into the wellbore such that the fluid invades the earth formation; a first logging tool for measuring at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; at least one other logging tool for measuring at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; means for determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasions into the earth formation at the points in time; and means for determining in response to said radii determinations the relative permeability of the earth formation.

Claim 7

A system for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising: means for injecting a fluid into the wellbore such that the fluid invades the earth formation; a first logging tool for measuring at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; at least one other logging tool for measuring at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; means for determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasions into the earth formation at the points in time; and means for determining in response to said radii determinations the relative permeability of the earth formation.

Claim 10

A method for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; measuring with a first logging tool at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; measuring with at least one other logging tool at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasion into the earth formation at the points in time; and determining in response to said radii determinations the relative permeability of the earth formation.

Claim 11

A method for determining the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; measuring with a first logging tool at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; measuring with at least one other logging tool at at least one point in time a quantity that varies in response to the radius from the wellbore axis of the fluid invasion into the earth formation; determining in response to said quantity measurements the radius from the wellbore axis of the fluid invasion into the earth formation at the points in time; and determining in response to said radii determinations the relative permeability of the earth formation.

Claim 14

A method of calculating the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; determining at different points in time the diameter of fluid invasion into the earth's formation from the wellbore axis at a first point along the wellbore; determining the porosity of the earth formation surrounding the wellbore at said first point; determining the wellbore diameter at said first point; determining substantially at said different points in time the diameter of fluid invasion into the earth's formation from the wellbore axis at a second point along the wellbore; determining the porosity of the earth formation surrounding the wellbore at said second point; determining the wellbore diameter at said second point; and calculating the relative permeability of the earth formations surrounding the wellbore at said first and second points according to the equation: ##EQU11## where K A is the permeability of the earth formation surrounding the wellbore at said first point, where K B is the permeability of the earth formation surrounding the wellbore at said second point, where φ A is the porosity of the earth formation surrounding the wellbore at said first point, where φ B is the porosity of the earth formation surrounding the wellbore at said second point, where D OA is the wellbore diameter at said first point, where D OB is the wellbore diameter at said second point, where D i1A is the diameter of fluid invasion at a first time at said first point, where D i2A is the diameter of fluid invasion at said second time at said first point, where D i1B is the diameter of fluid invasion substantially at said first time at said second point, and where D i2B is the diameter of fluid invasion substantially at said second time at said second point.

Claim 15

A method of calculating the relative permeability of an earth formation surrounding a wellbore having a longitudinal axis comprising the steps of: injecting a fluid into the wellbore such that the fluid invades the earth formation; determining at different points in time the diameter of fluid invasion into the earth's formation from the wellbore axis at a first point along the wellbore; determining the porosity of the earth formation surrounding the wellbore at said first point; determining the wellbore diameter at said first point; determining substantially at said different points in time the diameter of fluid invasion into the earth's formation from the wellbore axis at a second point along the wellbore; determining the porosity of the earth formation surrounding the wellbore at said second point; determining the wellbore diameter at said second point; and calculating the relative permeability of the earth formations surrounding the wellbore at said first and second points according to the equation: ##EQU11## where K A is the permeability of the earth formation surrounding the wellbore at said first point, where K B is the permeability of the earth formation surrounding the wellbore at said second point, where φ A is the porosity of the earth formation surrounding the wellbore at said first point, where φ B is the porosity of the earth formation surrounding the wellbore at said second point, where D OA is the wellbore diameter at said first point, where D OB is the wellbore diameter at said second point, where D i1A is the diameter of fluid invasion at a first time at said first point, where D i2A is the diameter of fluid invasion at said second time at said first point, where D i1B is the diameter of fluid invasion substantially at said first time at said second point, and where D i2B is the diameter of fluid invasion substantially at said second time at said second point.