Abstract: Method and apparatus for completing a plurality of zones in a wellbore. A packer having a tubular element extending therethrough is suspended in a wellbore between two hydrocarbon-bearing zones of interest. The lower zone is perforated and stimulated if necessary. Thereafter, the tubular element is sealed with a plug which includes an explosive charge and the upper zone is fractured and stimulated. The explosive is then detonated thus severing the tubular element at the plug thereby permitting production of formation fluids from both zones into a common string of tubing.

Abstract: Corrosion and erosion of metal well casings due to production of corrosive well fluids, especially geothermal brines, is avoided by producing corrosive fluids through an impermeable cement wellhousing comprised of inner and outer substantially continuous cement liners which envelop and insulate from corrosion and erosion a conventional outer metal or other well casing while the outer casing internally reinforces the cement well housing. A second, sacrificial metal casing of smaller diameter is used in cementing the inner cement liner and can be substantially corroded away by corrosive fluids without substantial damage to the remaining cement wellhousing or outer casing through which corrosive fluids are produced. An apparatus for producing corrosive fluids, particularly geothermal brine, contained in a subterranean formation is also disclosed.

Abstract: A downhole tool is actuated at chosen well depth by selection of a control element that melts at the chosen depth well temperature. In one form of tool, a fusible pin melts to release spring-loaded jaws which move against an expansion cone to anchor the tool in the well. In another form, a fusible receptacle cover melts to release a quantity of dense fluid under action of gravity. Suitable control elements are formed of bismuth, with lead and zinc.

Abstract: A hydraulic control communication nipple for switching control fluid in a fluid passageway from one location to a second location. A metal plug is aligned with a portion of the fluid passageway and is positioned to be engaged by a vertically moving sleeve and moved into said portion to shut off fluid communication to a first location. The plug is a frangible plug that includes a longitudinal axis extending vertically into the passageway and includes threads screwed into and forming a metal-to-metal seal with the passageway. The movement of the plug into the portion of the passageway may also open communication of the passageway with the second location. For alternately opening the passageway to a second location, a metal breakable screw having a longitudinal axis extending vertically into the passageway adjacent the second location has threads screwed into and initially blocks the passageway with a metal-to-metal seal. The screw includes a cavity exposed to the passageway.

Abstract: A method for placing a perforated liner in a well penetrating a reservoir containing a high pressure fluid, for example, a geothermal fluid. The holes in one or more sections of a preperforated liner are temporarily closed by inserting therein hollow plugs having an open flange end at the outer surface of the liner and a closed end projecting into the bore of the liner. The lower end of a first section of liner is also closed as with a solid plug. The liner, made up of one or more of the above-described sections which have been joined together, is run into the well through a pressure sealing device at the wellhead, such as a stripper rubber or rotating head. When the liner has been properly positioned in the well, a cutting or scraping tool is run down the inside of the liner to remove the closed end of each plug projecting into the liner, thus opening the perforations in the liner. Reservoir fluids can be produced through the well around the outside of the liner while the liner is being placed.

Abstract: A method and means for pulling a sucker rod string from a well is disclosed. A separable connector is provided in the sucker rod string above the pump body. The connector comprises a male and a female section having aligned openings and joined by a shear pin within said openings. The force required to shear the pin and separate the sections of the connector is substantially greater than that required for normal operation of a downhole reciprocating pump or similar tool but is substantially less than the weight of the fluid column above the downhole reciprocating pump. The disclosed methods include insertion of this connector into a sucker rod string, such as one including fiberglass sucker rods, above the pump. The pump is then operated in the normal known fashion. To remove the sucker rod string, tension in the string is increased above that required to operate the pump until the pin within the connection shears, separating the sucker rod string from the pump.

Abstract: A method of pushing pipe (e.g., casing) into a highly deviated borehole. The lower end of the pipe is plugged and the lower portion of the pipe string is filled with fluids (e.g., compressed gases, petroleum products, water, etc.) which have a lower density than that of the borehole fluid. This creates a buoyancy effect for the pipe in the deviated portion of the borehole which aids in keeping the pipe from contacting the lower side of the deviated hole. The pipe can be plugged or capped above the lightened section and filled with heavier fluid to aid in forcing the pipe downward into position. The plugs and caps are then removed, e.g., drilled out, when the pipe is ready for use. The fluids are thereby released into the mud slurry.

Abstract: A method and apparatus are disclosed for sequentially treating two vertically separated zones in a well bore, utilizing a packer having a fluid passageway therethrough set between the zones, a pressure shearable plug at the lower end of the packer, and a retrievable fluid plug at the upper end of the packer. Once the packer, with the shear plug on its lower end, is set in the well bore between the two zones, the retrievable plug is placed in the upper end of the packer to isolate the shear plug from well pressure in the upper zone, and the desired treating steps are performed on the upper zone. The retrievable fluid plug is then removed and tubing run to the packer to establish communication with the shearable fluid plug. The shearable plug permits static pressure testing of the tubing string and seals before communication is established with the lower zone, and then may be removed by elevating fluid pressure to sufficiently shear the plug.