Downhole steam injector

• US 4,366,860 A
• Filed: 06/03/1981
• Issued: 01/04/1983
• Est. Priority Date: 06/03/1981
• Status: Expired due to Fees

• Current Assignee: United States Department of Energy
• Original Assignee: United States Department of Energy
• Inventors: Donaldson, A. Burl, Hoke, Donald E.
• Primary Examiner(s): Novosad, Stephen J.
• Application Number:
  US06/269,460
• Time in Patent Office: 580 Days
• Field of Search: 431/158, 431/238, 431/243, 166/59, 166/63, 166/57, 166/303, 166/302, 166/256, 166/261, 175/14
• US Class Current: 166/59
• CPC Class Codes: E21B 36/00 Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
• CPC Class Codes: E21B 36/001 Cooling arrangements
• CPC Class Codes: E21B 36/02 using burners
• CPC Class Codes: F22B 1/26 Steam boilers of submerged-flame type, i.e. the flame being surrounded by, or impinging on, the water to be vaporised , e.g. water in sprays

Abstract

An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

Claims

1. A downhole steam injector comprising:

a solid cylindrical top head having separate orifices extending from an outer surface through the head for oxidant and fuel;

a hollow cylindrical body fastened at a top end to said top head;

orifice means for the passage of water from an outer surface to an inner surface of said body at a location adjacent the bottom end of said body;

a hollow cylindrical middle sleeve supported at a top end by said top head, said sleeve being axially aligned with and spaced from said body;

means at said top head for the passage of water from the outer to the inner surface of said middle sleeve;

a hollow cylindrical inner sleeve fastened at a top end to said top head, said inner sleeve being axially aligned with and spaced from said middle sleeve;

an annular water injector fastened at the bottom end of said inner sleeve and having an outer surface contiguous with an inside surface of said middle sleeve, said injector having longitudinal water passages extending between opposed end surfaces;

a reducer axially aligned with said sleeves comprising a hollow truncated cone having a large top diameter fastened to the bottom end of said middle sleeve and a small bottom diameter;

a cylindrical outlet pipe axially aligned with said sleeves having a top end fastened to the small end of said reducer sleeve;

and a cylindrical bottom head providing a water tight seal between the bottom end of said body and the outer surface of said outlet pipe.

2. The downhole steam injector of claim 1 wherein said top head has opposed outer and inner end surfaces, said fuel orifice extends from said outer surface to an end at an inner location, said oxidant orifice extends from said outer end surface to said inner surface and includes a straight portion passing adjacent the inner location and intersecting said inner end surface, and a passage orifice extends between the inner location of said fuel orifice and the straight portion of said oxidant orifice, the axis of said passage orifice being normal to the axis of the straight portion.

3. The downhole steam injector of claim 1 wherein the inner surface of the bottom end of said inner sleeve and an inner surface of said annular water injector are beveled.

4. The downhole steam injector of claim 1 wherein said orifice means extends through said body, the axis of said orifice forming an angle within the range of 30 to 60 degrees with a radius of said body.

5. A downhole steam injector comprising:

a solid cylindrical top head having separate orifices extending from an outer surface through the head for oxidant and fuel;

a hollow cylindrical body fastened at one end to said top head, said body having a water orifice extending from an outer surface to an inner surface at a location adjacent the other end, the axis of said orifice being in a plane perpendicular to the axis of said body and forming an angle within the range of 30 to 60 degrees with a radius of said body;

a hollow cylindrical middle sleeve supported at one end by said top head, said middle sleeve being axially aligned with and spaced from said body;

means at said top head for the passage of water from the outer to the inner surface of said middle sleeve;

a hollow cylindrical inner sleeve fastened at one end to said top head, said inner sleeve being axially aligned with and spaced from said middle sleeve;

an annular water injector fastened at the other end of said inner sleeve and having an outer surface contiguous with an inside surface of said middle sleeve, said injector having longitudinal water passages extending between opposed end surfaces;

an elongated hollow structure axially aligned with said sleeves extending from the other end of said middle sleeve;

a cylindrical bottom head extending from the other end of said body to the outer surface of said hollow structure.

6. The downhole steam injector of claim 5 wherein the angle of said axis is approximately 45 degrees.

7. A downhole steam injector comprising:

a solid cylindrical top head having separate orifices extending from an outer surface through the head for oxidant and fuel;

a hollow cylindrical body fastened at a top end to said top head;

orifice means for the passage of water from an outer surface to an inner surface of said body at a location adjacent to the bottom end of said body;

a hollow cylindrical middle sleeve supported at a top end by said top head, said sleeve being axially aligned with and spaced from said body;

means at said top head for the passage of water from the outer to the inner surface of said middle sleeve;

a hollow cylindrical inner sleeve fastened at a top end to said top head, said inner sleeve being axially aligned with and spaced from said middle sleeve;

said inner sleeve having a beveled inner surface at the bottom end;

an annular water injector having an outer surface contiguous with the inner surface of said middle sleeve and an inner surface conforming to and affixed to the beveled end of said inner sleeve, said injector having longitudinal water passages extending between opposed end surfaces;

an elongated hollow structure axially aligned with said sleeves extending from the bottom end of said middle sleeve;

a cylindrical bottom head providing a water-tight seal between the bottom end of said body and the outer surface of said hollow structure.

8. The downhole steam injector of claim 7 wherein the outer surface of said annular water injector contains a plurality of spaced longitudinal grooves which form the water passages.

9. A downhole steam injector comprising:

a solid cylindrical top head having opposed outer and inner end surfaces;

a fuel orifice extending from said outer surface to an end at an inner location;

an oxidant orifice extending from said outer surface to said inner surface, a straight portion of said oxidant orifice passing adjacent the inner location and intersecting said inner surface; and

a passage orifice extending between the inner location of said fuel orifice and said straight portion of said oxidant orifice, the axis of said passage orifice being normal to the axis of said straight portion;

a hollow cylindrical body fastened at a top end to said top head;

orifice means for the passage of water from an outer surface to an inner surface of said body at a location adjacent the bottom end of said body;

a hollow cylindrical middle sleeve supported at a top end by said top head, said sleeve being axially aligned with and spaced from said body;

means at said top head for the passage of water from the outer to the inner surface of said middle sleeve;

a hollow cylindrical inner sleeve fastened at a top end to said top head, said inner sleeve being axially aligned with and spaced from said middle sleeve, said sleeve encircling said oxidant orifice on said top head;

an annular water injector fastened at the bottom end of said inner sleeve and having an outer surface contiguous with an inside surface of said middle sleeve, said injector having longitudinal water passages extending between opposed end surfaces;

an elongated hollow structure axially aligned with said sleeves extending from the bottom end of said middle sleeve;

a cylindrical bottom head providing a water-tight seal between the bottom end of said body and the outer surface of said hollow structure.

10. A downhole steam injector comprising:

a cylindrical body having a top end, a bottom end, opposed outer and inner side surfaces and a water orifice extending secantly from said outer surface to inner surface at said lower end;

a solid cylindrical top head comprising opposed outer and inner end surfaces;

a first side portion having an outer diameter as large as the diameter of said outer side surface of said body, an inwardly extending shoulder portion, and a second side portion having an outer diameter smaller than the diameter of said inner side surface of said body and longitudinal grooves extending from said inner end surface;

a fuel orifice extending from said outer surface to an end at an inner location;

an oxidant orifice extending from said outer surface to said inner end surface, a straight portion of said oxidant orifice passing adjacent the inner location and intersecting said inner surface; and

a passage orifice connecting the inner location of said fuel orifice and said straight portion of said oxidant orifice, the axis of said passage orifice being normal to the axis of said straight portion;

a hollow cylindrical middle sleeve having top and bottom ends, an outer diameter less than the diameter of the inner side surface of said body, the inner surface of said sleeve forming a tight, sliding fit at the top end over the grooves of the second side portion of said top head;

a hollow reducer sleeve having a large end of equal size as and fastened to the bottom end of said middle sleeve, and a small end of reduced diameter, the length of said middle sleeve and said reducer sleeve being less than the length of said body;

an outlet pipe having a diameter of equal size as the small end of said reducer sleeve, a top end fastened to the small end, and a bottom end extending past the bottom end of said body;

a cylindrical bottom head having an orifice of diameter equal the outer diameter of said outlet pipe extending between opposed inner and outer end surfaces, said pipe extending through said orifice, the bottom end of said body being fastened to the inner end surface of said bottom head;

an inner sleeve of shorter length than said middle sleeve having an outer diameter smaller than the diameter of the inner surface of said middle sleeve, a top end fastened to the inner end surface of said top head and a beveled inner surface at the bottom end;

an annular water injector having a longitudinally grooved outer surface contiguous with the inner surface of said middle sleeve and an inner surface conforming to and affixed to the beveled end of said inner sleeve; and

means for injecting water into the water orifice at the outer surface of said body, whereby water flows up the chamber formed by the inner surface of the bottom head, inner surface of the body and the outer surface of the outlet pipe, reducer sleeve and middle sleeve to the shoulder of said top head, through the grooves in the second side portion of the top head, down the chamber formed by the inner surface of the middle sleeve and the outer surface of said inner sleeve and into the combustion chamber through the grooves in the water injector.