Method for determining the azimuth and length of a deep vertical fracture in the earth

摘要

In the hydraulic fracturing of deep geologic formations for the production of fluid hydrocarbons, and where vertical fractures are formed, a method is described, using seismic geophysical techniques, for determining the azimuth and length of the fractures. This is accomplished by injecting into the formation through the fracture a selected fluid, or producing the fluid hydrocarbons from the formation into the fracture, until the formation, over a selected distance from the walls of the fracture, has a different gas saturation from the condition in the formation farther from the fracture. This condition is mapped by seismic methods.