초록 ▼

A propellant is ignited within a well to rapidly produce combustion gases to generate pressure exceeding the fracture extension pressure of the surrounding formation. Combustion gases are generated at a rate greater than can be absorbed into any single fracture, thereby causing propagation of multip

A propellant is ignited within a well to rapidly produce combustion gases to generate pressure exceeding the fracture extension pressure of the surrounding formation. Combustion gases are generated at a rate greater than can be absorbed into any single fracture, thereby causing propagation of multiple fractures into the surrounding formation. In one embodiment, each segment of the propellant is in the form of a solid cylindrical body of fuel/oxidizer surrounded by an expandable casing made of a material similar to a fire hose. A linear shaped charge extends between the casing and the propellant. Upon ignition of the shaped charge, combustion gases quickly stretch the casing thereby allowing the hot gases to surround and ignite the entire propellant surface area. The propellant then burns in a radially inward direction in a predictable manner. A computer program can be used to model the burn rate of the propellant to predict the resulting generation of combustion gases and fracture propagation, and thereby determine a suitable quantity and configuration of the propellant for creating multiple fractures in the surrounding formation.

대표청구항 ▼

A method of creating multiple fractures in the formation surrounding at least a portion of the length of a horizontal well, said method comprising the steps of: selecting a combination of a fuel and an oxidizer for use in a solid propellant having a predetermined outer surface configuration and mean

A method of creating multiple fractures in the formation surrounding at least a portion of the length of a horizontal well, said method comprising the steps of: selecting a combination of a fuel and an oxidizer for use in a solid propellant having a predetermined outer surface configuration and means to ignite said outer surface; modeling the burn rate of said outer surface of said propellant within said well to predict the resulting generation of combustion gases and fracture propagation, and thereby determine a suitable amount of said propellant to cause propagation of multiple fractures into said surrounding formation from said well; introducing said propellant into said well adjacent to the portion of said formation to be fractured; and igniting said outer surface of said propellant to cause the propellant to burn in a radially inward direction to rapidly produce combustion gases to generate pressure within said well exceeding the fracture extension pressure of said formation for a period of time, with said combustion gases being generated at a rate greater than can be absorbed into any single resulting fracture, thereby causing propagation of multiple fractures into said surrounding formation from said well.