Microwave system and method for intrinsic permeability enhancement and extraction of hydrocarbons and/or gas from subsurface deposits

Abstract

A system of a radiating antenna and a sheet beam klystron, as a microwave source, coupled to the antenna by a short waveguide and the method of locating the antenna downhole in a well at a selected target zone by use of a dual chamber flexible tube and applying power to the source to heat and fracture the rock in the target zone and created a migrating phase boundary that radiates out from the antenna 25 meters or more to release the hydrocarbons in the rock.

What is claimed is: 
     
         1 . A method of inducing increased permeability at a selected target area downhole in a well comprising lowering to the target area a system including a sheet beam klystron as the source of microwave energy, a recirculator, a dummy load, and a directional antenna. 
     
     
         2 . The method in accordance with  claim 1  further comprising positioning the antenna in the target area and pointing it in a selected direction to cover a selected sector. 
     
     
         3 . The method in accordance with  claim 2 , further comprising applying DC power to the klystron through a power cable from a generator on the surface. 
     
     
         4 . The method in accordance with  claim 3 , further comprising applying the DC voltage at a selected low level and then increasing the voltage to an operating level in response to a measured parameter downhole or on a set schedule. 
     
     
         5 . The method in accordance with  claim 3 , further comprising employing a dual chamber flexible tube for lowering the system to the target area and recirculating a coolant from the surface through one chamber, downhole in contact with the source of microwave energy, recirculator, dummy load and antenna and back to the surface through the second chamber in the flexible tubing. 
     
     
         6 . A method of intrinsic permeability enhancement at a selected subsurface level to release hydrocarbon liquids and gases at the selected subsurface level by employing a sheet beam klystron as the source of microwave energy coupled to a directional antenna, the method comprising positioning the source downhole near the directional antenna and positioning the directional antenna at the selected subsurface level and applying power to the source of microwave energy. 
     
     
         7 . The method of intrinsic permeability enhancement at a selected subsurface level in accordance with  claim 6 , further comprising fracturing the rock at the selected level and increasing the rock permeability by increasing the interconnected porosity resulting in increased hydrocarbon delivery efficiency. 
     
     
         8 . The method of intrinsic permeability enhancement at a selected subsurface level in accordance with  claim 6 , further comprising the further steps of fracturing the rock at the selected level and separating during fracturing selected hydrocarbons. 
     
     
         9 . The method in accordance with  claim 6 , wherein a well has been drilled to a depth to reach the selected level, the method further comprising vaporizing a portion of the material at the selected subsurface level and creating a sufficient pressure differential between the area where the material is vaporized and the drilled well to push the hydrocarbons into and up the well. 
     
     
         10 . The method in accordance with  claim 6 , further comprising applying microwave energy to form a phase boundary extending away from the antenna. 
     
     
         11 . The method in accordance with  claim 10 , further comprising extending the phase boundary 25 meters or more from the antenna. 
     
     
         12 . The method in accordance with  claim 10 , further comprising applying microwave energy at a sufficient density to vaporize a portion of the material in the phase boundary to create a pressure differential between the area in the phase boundary and the drilled well. 
     
     
         13 . The method in accordance with  claim 6 , further comprising applying power from the surface through a cable to the source and circulating a coolant from the surface to the source and antenna. 
     
     
         14 . The method in accordance with  claim 6 , further comprising positioning the antenna to cover a selected sector and rotating the antenna a selected number of degrees to cover another sector and applying power to the source. 
     
     
         15 . The method in accordance with  claim 6 , further comprising closing the casing at the surface and controlling the temperature in the selected level. 
     
     
         16 . The method in accordance with  claim 6 , further comprising closing the casing at the surface and controlling the pressure in the casing. 
     
     
         17 . The method in accordance with  claim 6 , further comprising the producing superheated steam or other critical or super critical fluids in the target formation to enhance hydrocarbon removal rates. 
     
     
         18 . A system for in-situ extraction of hydrocarbons from a target formation in a well comprising: a casing in the well, a well screen of low dielectric material at the lower end of the casing in the target formation, a source of microwave energy and a radiating antenna positioned in the casing at the target formation, and a short waveguide coupling the source of microwave energy to the antenna. 
     
     
         19 . A system for creating a subsurface permeable cylinder by fracturing an unfractured rock at selected depths comprising a radiating antenna and a source of microwave energy near the antenna to expose a large surface area of unfractured rock to allow low hydrocarbon desorption rates that are compensated with large cross sectional areas for efficient and productive gas wells. 
     
     
         20 . A method of creating a subsurface permeable cylinder as a reservoir comprising fracturing the rock at selected depths by a downhole system including a radiating antenna and a source near the antenna to expose a large surface area of unfractured rock to provide a reservoir and sequestering carbon in the reservoir. 
     
     
         21 . The method of sequestering carbon in accordance with  claim 20 , further comprising pressurizing the reservoir and locating one or more hydrocarbon producing wells near the reservoir to enhance hydrocarbon production.