EMU impulse antenna

A system for using pulses of electromagnetic energy to travel through a subsurface hydrocarbon reservoir for electromagnetic imaging of the subsurface hydrocarbon reservoir, the system comprising:

• at least one electromagnetic energy source, each electromagnetic energy source including:
• a sonde assembly attached to a wireline for travel in a well borehole to a depth of interest, the sonde assembly including a first section axially aligned with, and spaced from, a second section;
• an energy storage capacitor formed by a conductor member extending along the sonde assembly, an electrode mounted in each of the first section and the second section of the sonde assembly and serving as a second conductor, and a capacitive charge storage medium mounted in each of the first section and the second section of the sonde assembly between the sonde assembly and the electrode, where the capacitive charge storage medium is formed of a material that includes iron particles and an epoxy matrix;
• and
• a fast-closing switch located between one of the conductor members and the electrodes of the first and second sections;
• and
• a plurality of electromagnetic sensors forming a measure of a resulting signal from the electromagnetic energy source.

A method for emitting pulses of electromagnetic energy with an electromagnetic energy source, the method comprising:

• providing an electromagnetic energy source having:
• a sonde assembly including a first section axially aligned with, and spaced from, a second section;
• an energy storage capacitor including an electrode mounted in each of the first section and the second section of the sonde assembly and a capacitive charge storage medium mounted in each of the first section and the second section of the sonde assembly and surrounding the electrode, where the capacitive charge storage medium is formed of a material that includes iron particles and an epoxy matrix;
• and
• a fast-closing switch located between the electrodes of the first and second sections;
• and
• charging the energy storage capacitor to cause the fast-closing switch to close and pulses of electromagnetic energy to be emitted from the electromagnetic energy source.

A method for electromagnetic imaging of a subsurface hydrocarbon reservoir, the method comprising:

• lowering an electromagnetic energy source on a wireline in a well borehole to a depth of interest in the subsurface hydrocarbon reservoir, the electromagnetic energy source including:
• a sonde assembly attached to the wireline for travel in the well borehole, the sonde assembly including a first section axially aligned with, and spaced from, a second section;
• an energy storage capacitor formed by a conductor member of the sonde assembly, an electrode mounted in each of the first section and the second section of the sonde assembly and serving as an inner conductor, and a capacitive charge storage medium mounted in each of the first section and the second section of the sonde assembly between the conductor member and the electrode, where the capacitive charge storage medium is formed of a material that includes iron particles and an epoxy matrix;
• and
• a fast-closing switch located between one of the conductor members and the electrodes, of the first and second sections;
• and
• emitting pulses of electromagnetic energy with the electromagnetic energy source to travel through the subsurface hydrocarbon reservoir.