Abstract Following is disclosed acoustical well fracturing methods and apparatus whereby pressure fluctuations are generated in a well bore by pumping fluid through a first conduit to drive an acoustical oscillator coupled with an acoustical compliance that transmits the pressure fluctuations to a formation of the earth in a selected zone of the well bore. The well bore, which functions as a second conduit that contains the first conduit and the oscillator, returns fluid flow back toward a pump means. A variable restriction means such as a valve is used to adjust the back pressure in the well bore such that the maximum oscillated fluid pressure exceeds that pressure required for formation fracture. To achieve fracture only in the selected zone, acoustical isolation means are spaced above and below the acoustical oscillator to confine the pressure fluctuations to that zone. Also, in another embodiment the density of the fluid circulated in the well bore is selectively varied to achieve fracture in the selected zone.
An acoustical method for fracturing selected zones in a well bore comprising the steps of: pumping a fluid down a well bore through a first conduit; oscillating the pressure in said fluid within the well bore; coupling the resulting fluid pressure oscillations with the bore hole wall at a selected depth; isolating the fluid pressure oscillations to a selected zone to be fractured; returning the fluid flow between the first conduit and a second conduit formed at least partially by the wall of the well bore; increasing the density of the fluid to control the fluid pressure in the well bore to initiate fracture in the selected zone.
Claim 2
Dependent Claim
108 words
An acoustical method for fracturing selected zones in a well bore comprising the steps of: pumping a fluid down a well bore through a first conduit; oscillating the pressure in said fluid within the well bore; coupling the resulting fluid pressure oscillations with the bore hole wall at a selected depth; isolating the fluid pressure oscillations to a selected zone to be fractured; returning the fluid flow between the first conduit and a second conduit formed at least partially by the wall of the well bore; increasing the density of the fluid to control the fluid pressure in the well bore to initiate fracture in the selected zone.
Claim 3
Dependent Claim
131 words
An acoustic method for fracturing selected zones in a well bore comprising the steps of: pumping a fluid down a well bore through a first conduit; oscillating the pressure in said fluid within the well bore; coupling the resulting fluid pressure oscillations with the well bore wall in a selected zone; isolating the fluid pressure oscillations to a selected region adjacent the selected formation to be fractured; returning the fluid flow between the first conduit and a second conduit formed at least partially by the wall of the well bore; controlling from the surface of the earth the restriction to the flow of fluid from said second conduit and increasing the density of the fluid to control the fluid pressure in the well bore to initiate fracture in the selected zone.
Claim 4
Dependent Claim
131 words
An acoustic method for fracturing selected zones in a well bore comprising the steps of: pumping a fluid down a well bore through a first conduit; oscillating the pressure in said fluid within the well bore; coupling the resulting fluid pressure oscillations with the well bore wall in a selected zone; isolating the fluid pressure oscillations to a selected region adjacent the selected formation to be fractured; returning the fluid flow between the first conduit and a second conduit formed at least partially by the wall of the well bore; controlling from the surface of the earth the restriction to the flow of fluid from said second conduit and increasing the density of the fluid to control the fluid pressure in the well bore to initiate fracture in the selected zone.