Marine em exploration
AssigneePGS EM Limited
InventorAntoni Ziolkowski
Life of this patent
Estimating the term…
Abstract
A method for removing the effects of an airwave from marine electromagnetic data comprising providing an electromagnetic source and at least one receiver in the water; measuring the electromagnetic response at a first source-receiver separation; determining a scaled version of the airwave response at a source-receiver separation where the earth response is negligible and using the scaled airwave response to determine the earth response measured at the first separation. Using this method, an improved estimate of the earth's response can be achieved.
Claims24
A method for determining the earth response to an electromagnetic signal using a source for transmitting the electromagnetic signal to at least one receiver in water, the method comprising:
- using an electromagnetic response measured at a first source-receiver separation;
- determining the airwave response or a scaled version thereof at a source-receiver separation where the earth response is negligible and using the determined airwave response to determine the earth response measured at the first separation.
A system for determining the earth response to an electromagnetic signal using an electromagnetic source and at least one receiver in water, the system being adapted to measure the electromagnetic response at a first source-receiver separation;
- determine the airwave response or a scaled version thereof at a source-receiver separation where the earth response is negligible and use the determined airwave response to determine the earth response measured at the first separation.
A computer program, preferably on a computer readable medium or data carrier, and/or computer program product and/or a processor for processing marine electromagnetic data measured by at least one source and at least one receiver to remove the effects of an airwave, wherein the computer program/product/processor has code or instructions for using an airwave response at a source-receiver separation where the earth response is negligible to allow removal of an airwave response in measurements at a shorter source-receiver separation, thereby to allow the earth response to be determined.
A method of measuring an electromagnetic response comprising positioning an electromagnetic source and at least one electromagnetic receiver underwater;
- transmitting an electromagnetic signal from the source to the receiver, wherein the transmitted signal comprises an earth component and an airwave component, and the receiver is positioned relative to the source so that the measured response is substantially due to the airwave.
Dependencies are inferred from the claim text.