System and process for secondary hydrocarbon recovery
AssigneeLockheed Martin Corporation
InventorsManik Talwani, Walter K Feldman, Melvin Schweitzer
Life of this patent
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Abstract
A hydrocarbon reservoir undergoing secondary recovery is subject to a first and then at least a second gravity gradient survey in which a gravity gradiometer takes gradient measurements on the surface above the reservoir to define successive data sets. The differences between the first and subsequent gravity gradient survey yields information as to sub-surface density changes consequent to displacement of the hydrocarbon and the replacement thereof by the driveout fluid including the position, morphology, and velocity of the interface between the hydrocarbon to be recovered and the driveout fluid.
Claims22
A process for controlling fluid hydrocarbon production from a sub-surface hydrocarbon reservoir undergoing secondary recovery by injection of a driveout fluid therein and from which fluid hydrocarbons are removed in response to the driveout fluid injection, comprising:
- establishing a plurality of measurement positions for the measurement of the local gravity gradient;
- performing a first assay of the gravity gradient above the reservoir;
- performing at least a second assay of the gravity gradient above the reservoir, said first and second assay separated by a period of time;
- identifying the position of the interface between the driveout fluid and the fluid hydrocarbons from data between the first and second assays;
- and
- controlling the injection of the driveout fluid to control removal of the hydrocarbons from the reservoir.
A process for monitoring an interface between a driveout fluid and fluid hydrocarbons in a sub-surface reservoir undergoing secondary recovery by injection of the driveout fluid therein and from which fluid hydrocarbons are removed at least in response to the injection of the driveout fluid, comprising:
- performing a first set of measurements of the gravity gradient at a plurality of measurement positions;
- performing at least a second set measurements of gravity gradient at each of the measurement positions, said first and second sets of measurements separated by a period of time;
- identifying the position of the interface between the driveout fluid and the fluid hydrocarbons from difference data between the first and second assays;
- and
- displaying position of the interface between the driveout fluid and the fluid hydrocarbons.
A system for monitoring the interface between a driveout fluid and a fluid hydrocarbons in a sub-surface reservoir undergoing secondary recovery by injection of a driveout fluid therein and from which fluid hydrocarbons are removed at least in response to the injection of the driveout fluid, said system comprising:
- means for establishing a plurality of measurement positions for the measurement of the local gravity gradient above the reservoir;
- a gravity gradient measuring instrument moved to at least some of said measurement positions for measuring the gravity gradient at each of said measurement positions to obtain a first set of gravity gradient data and for movement, at a time subsequent to the time the first set of data was obtained, to at least some of said measurements to obtain a second set of gravity gradient data;
- a data processor for processing the first and second set of data to identify the position of the interface between the driveout fluid and the fluid hydrocarbon from difference data between the first and second sets of data, and
- a display device for displaying the so-identified position of the interface.
A process for monitoring the interface between a first fluid and a second fluid in a sub-surface volume in which one of said first and second fluids displaces the other of said first and second fluids with time, comprising:
- establishing a plurality of measurement positions for the measurement of the local gravity gradient;
- performing a first set of measurements of the gravity gradient at the surface above the sub-surface volume;
- performing at least a second set of measurements of gravity gradient at the surface above the sub-surface volume, said first and second measurements separated by a period of time;
- identifying the position of the interface between the first fluid and the second fluid from at least difference data between the first and second sets of measurements;
- and
- displaying the position of the interface between the first and second fluids.
A process for monitoring the sub-surface migration of at least a first fluid in a sub-surface volume in which the first fluid migrates in the sub-surface volume with time, comprising;
- establishing a plurality of measurement positions for the measurement of the local gravity gradient;
- performing a first set of measurements of the gravity gradient at the surface above the sub-surface volume;
- performing at least a second set of measurements of gravity gradient at the surface above the sub-surface volume, said first and second measurements separated by a period of time;
- identifying the position of the edge of the at least first fluid from at least difference data between the first and second sets of measurements;
- and
- displaying the position of the edge of the at least first fluid.
Dependencies are inferred from the claim text.