Abstract: Methods, systems, and articles of manufacture consistent with the present invention provide for determining the orientation of natural fractures in the Earth resulting from hydraulic fracturing treatment. Data attribute information from a far-field point-source signal profile for a microseismic event is extracted in the time domain. An estimate of the orientation of the natural fracture is calculated in the time domain based on the extracted data attribute information.

Abstract: In oil and gas production, a process known as hydraulic fracturing is often used. Hydraulic fracturing involves pumping a fluid under pressure down a well bore into a fluid reservoir. When the pressurized fluid enters the reservoir, it produces localized failures of rock within the earth known as fractures. These fractures generate elastic waves known as microseisms that travel outward from the source of the fractures in a spherical wavefront. These microseisms can be measured with sensors located near the well bore, and their source determined. The microseismic wavefront is composed of compressional and shear waves. The amplitudes of the compressional and shear waves can be detected and measured and the ratio of the shear wave amplitude to the compressional wave amplitude which is known as the S/P ratio, can be determined.