Abstract: Methods and apparatus for creating a downhole buoyant casing chamber. The buoyant casing chamber may be created after the casing has been at least partially run into the wellbore. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. A method of the invention comprises running a length of casing into the well to a first step, forming a buoyant chamber in the casing, filling the chamber with buoyant fluid, either a gas or a light liquid, and running the casing to a second depth greater than the first depth. The apparatus used comprises a length of casing, a floating device disposed in a lower end of the casing and forming a lower boundary of a buoyant chamber, a packer for sealingly engaging the casing in an upper end of the buoyant chamber, and a volume of buoyant fluid to fill the chamber.

Abstract: Methods and apparatus for creating a downhole buoyant casing chamber. The buoyant casing chamber may be created after the casing has been at least partially run into the wellbore. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. A method of the invention comprises running a length of casing into the well to a first step, forming a buoyant chamber in the casing, filling the chamber with buoyant fluid, either a gas or a light liquid, and running the casing to a second depth greater than the first depth. The apparatus used comprises a length of casing, a floating device disposed in a lower end of the casing and forming a lower boundary of a buoyant chamber, a packer for sealingly engaging the casing in an upper end of the buoyant chamber, and a volume of buoyant fluid to fill the chamber.

Abstract: Methods and apparatus for creating a downhole buoyant casing chamber. The buoyant casing chamber may be created after the casing has been at least partially run into the wellbore. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. A method of the invention comprises running a length of casing into the well to a first step, forming a buoyant chamber in the casing, filling the chamber with buoyant fluid, either a gas or a light liquid, and running the casing to a second depth greater than the first depth. The apparatus used comprises a length of casing, a floating device disposed in a lower end of the casing and forming a lower boundary of a buoyant chamber, a packer for sealingly engaging the casing in an upper end of the buoyant chamber, and a volume of buoyant fluid to fill the chamber.

Abstract: A downhole apparatus and method for depositing metal at a desired area in a well casing. In one embodiment the apparatus comprises an oxygen tank filled with oxygen, a fuel tank filled with fuel, and a metal depositing device. An inert gas, such as nitrogen, may be supplied to dampen the heat generated by the metal depositing device. In an alternate embodiment, the apparatus comprises a gas tank with nitrous oxide therein and a sparking device to initiate a decomposition reaction to separate the nitrous oxide into its oxygen and nitrogen components. The metal depositing device may be adapted for flame spraying, plasma spraying or welding. A steering head is provided to reciprocate and rotate the apparatus so that the metal depositing device may be directed to the desired area in the casing. A camera and light are disposed at the bottom of the apparatus so that the interior of a well casing is illuminated and an image is transmitted to the operator for proper actuation of the steering sub.

Abstract: An apparatus and method for wellbore and formation heating. In the method, after perforation of the well, fracturing material is pumped into the perforations to fracture the formation. This fracturing material comprises a mixture of sand and thermosetting plastic. Heat is subsequently applied to the formation and thereby to the plastic to cause the plastic to set so that flow-back of the plastic and sand is prevented while still allowing fluid flow from the formation through the sand into the well casing. The heating apparatus comprises a dual tubing string with a burner chamber attached to the lower end thereof The outer tubing of the dual tubing string is adapted for connection to an oxygen source, and the inner tubing string is adapted for connection to a fuel source. The apparatus also comprises an ignition source for providing a spark to ignite the fuel and oxygen mixture.

Abstract: An apparatus for connecting a main casing section to a lateral casing section using thermoset plastic molding. The apparatus is used to set a flexible sock made of a hardenable material at a location adjacent to an intersection between the main and lateral casing sections. The sock is inflated so that it conforms to the inner surfaces of the main and lateral casing sections. Heat is applied to the hardenable material so that the sock is cured in the inflated, operating position. Heat may be applied by releasing chemicals which provide an exothermic reaction and/or by using a heater positioned within the sock.

Abstract: An apparatus and method for removing a frangible rupture disc or other frangible device from a wellbore casing. The casing has a special casing section defining a plurality of holes therethrough. Rupturable glass ceramic discs or inserts are disposed in the holes and retained therein. The glass ceramic discs or inserts are adapted to withstand fluid differential pressure normally present in the wellbore but are rupturable in response to impingement by a pressure wave thereon. The pressure wave is provided by a pressure wave generating device positionable in the casing string adjacent to the holes in the special casing section. The pressure generative device may generate a pressure pulse or an acoustical wave. Methods of perforating a well casing using a pressure pulse or an acoustical wave are also disclosed.

Abstract: A tapered connector for a tubing string. The present invention includes a tapered connector used in interconnecting sections of the tubing string having differing outside diameters. The connector is preferably conical and fixedly attached to the tubing portions in various ways, such as welding. The tubing string can be injected into a well by using a tubing injector with gripper blocks having a V-shaped groove defined therein adapted for engaging the different diameter tubing sections and the tapered connector and methods of injecting are also disclosed.

Abstract: A test, drill and pull system for testing a well formation or zone of interest and further drilling of the well in a single trip into the wellbore. The system includes a surface readout tester valve, a rotation-operated reversing valve, a resettable packer, a packer lockout, a perforated anchor and a drill bit. In operation, the apparatus is run into the bottom of the well adjacent to the formation or zone of interest and the packer set and unset as desired. With the packer set, a surface readout tester valve probe is lowered into the apparatus on a wireline and latched into the tester valve so that multiple testing operations may be carried out if desired. After testing, the fluid recovery may be reversed out and analyzed by actuating the reversing valve by rotation of the tool string. Further, rotation engages the packer lockout such that when weight is picked upon the packer, the packer cannot be reset.

Abstract: A wireless coiled tubing joint locator for locating joints or collars in a production tubing string. An electromagnetic coil assembly or giant magnetoresistive digital field sensor senses the increased mass of a pipe joint, and provides a signal to an electric circuit which generates a signal received by a pilot solenoid valve. The solenoid valve momentarily opens a pilot passageway which activates a piston to close a circulation port in the joint locator, resulting in an increase in a surface pressure reading observable by the operator. In one embodiment, a rupture disk is provided so that pressure cannot be applied to any downhole tool below the joint locator prematurely. A seat sleeve prevents premature communication of fluid to the rupture disk but can be opened by dropping a ball into the joint locator. A second embodiment may be used for either logging or washing operations or both. The electronic circuit can provide a selected one of a plurality of time delays.

Abstract: A method and apparatus using hydrajetting of fluid to cut a lateral casing window for drilling a side track. The apparatus comprises a J-sub having a J-slot therein which guides movement of a jetting nozzle such that a window may be abrasively jetted in well casing in the general shape of the J-slot. In an alternate embodiment, a hydraulically activated actuator sub is used to operate the J-sub. The actuator sub is activated by alternately pressurizing and depressurizing the actuator sub to apply longitudinal movement and torque to the J-sub.

Abstract: A wireless coiled tubing joint locator for locating joints or collars in a production tubing string. The joint locator is adapted for running into a well on coiled tubing, and other downhole tools may be connectable to the joint locator. An electromagnetic coil assembly senses the increased mass of a pipe joint, and provides a signal to an electric circuit which generates a momentary electric output signal received by a pilot solenoid valve. The solenoid valve momentarily opens a pilot passageway which activates a piston to close a circulation port in the joint locator. This closing of the circulation point results in an increase in a surface pressure reading observable by the operator. A rupture disk is provided so that pressure cannot be applied to any downhole tool below the joint locator prematurely, and a seat sleeve is provided to prevent premature communication of fluid to the rupture disk but can be opened at any time by dropping a ball into the joint locator.

Abstract: Integrated drilling and evaluation systems and methods for drilling, logging and testing wells are provided. The drilling and evaluation systems are basically comprised of a drill string, a drill bit carried on a lower end of the drill string for drilling a well bore, logging while drilling means included in the drill string for identifying subsurface zones or formations of interest, packer means carried on the drill string above the drill bit for sealing a zone or formation of interest below the packer means, and a fluid testing means included in the drill string for controlling the flow of well fluid from the zone or formation of interest into the drill string. The drilling and evaluation systems and methods for using the systems allow one or more subsurface zones or formations of interest in a well to be drilled, logged and tested without the necessity of removing the drill string from the well.

Abstract: A cryogenic pump manifold with subcooler and heat exchanger. The manifold comprises an inlet header with a subcooler disposed around it and a heat exchanger on the inlet side of the inlet header and subcooler. An expansion device is disposed between the inlet header and subcooler, and some liquid is diverted from the header and evaporated into a gas through the expansion device thereby lowering the temperature of the expanded gas which provides significant cooling to the cryogenic liquid entering the suction of the pump. An ejector may be positioned in the exhaust line from the heat exchanger to increase the flow rate, resulting in even more cooling. The cooling improves the overall performance of the pump and increases the ambient temperature range of operation of the pump. A method of cooling cryogenic liquid entering the suction of a pump is also disclosed.

Abstract: A low pressure, high temperature composite bridge plug. The bridge plug comprises a mandrel with a plurality of slips disposed therearound. A wedge is initially attached to said mandrel and in planar contact with the slips for forcing the slips radially outwardly into gripping engagement with a wellbore. An elastomeric sealing element is disposed on the mandrel and compressed between the wedge and a shoulder on the mandrel to expand the packing element radially outward into sealing engagement with the wellbore. A plurality of ratchets retained in a ratchet body grippingly engage the mandrel to prevent the plug from unsetting. The mandrel, slips, wedge and ratchet body are preferably made of non-metallic, composite materials for easy drilling.

Abstract: A cementing plug having a universal construction and improved wiping and extended wear characteristics. The cementing plug has a plug subassembly with a body member and an elastomeric jacket on the body member. The body member defines a central opening therethrough with a shoulder therein. To configure the plug as a bottom cementing plug, a shearable insert is positioned on the shoulder, and to configure the plug as a top cementing plug, a non-shearable insert is positioned on the shoulder. The shearable insert is one of a plurality of such inserts designed to shear at correspondingly different shear pressures. In a first embodiment, the shearable insert is a substantially flat disk having a uniform thickness, and in a second embodiment, the shearable insert has an outer ring portion and a relatively thin inner domed portion.

Abstract: A heavy-duty logging and perforating cablehead for coiled tubing. The cablehead includes an upper and lower housing which are shearably connected by shear pins. An actuating piston is slidably disposed in the housing. When the piston is in a running position, the piston holds a lug in locking engagement with the upper and lower housings such that the shear pins cannot be sheared. When the piston is moved to a releasing position, the lugs are released so that the upper and lower housings may be separated, thereby shearing the shear pins. Actuation of the piston is accomplished by pumping fluid down the coiled tubing and through a flow path in the cablehead and by applying pressure to the piston.

Abstract: A non-flashing fluid sampler for use in obtaining a well fluid sample. The sampler comprises a body defining a first chamber, a second chamber, a third chamber and a sampling port therein. The sampling port is in communication with the first chamber and with an outside zone outside the body. The second and third chambers are initially isolated from one another by a control valve. Upon activating the control valve, fluid may flow from the second chamber to the third chamber through a flow restriction. An extendable floating piston is disposed between the first and second chambers, and the floating piston defines a variable volume therein. An initial amount of well fluid flows into the variable volume, thus trapping dirty fluid, and subsequently, a well fluid sample is flowed into the first chamber. An isolation valve is provided for allowing hydrostatic pressure into the sampler after the fluid sample has been taken.

Abstract: A non-flashing fluid sampler for use in obtaining a well fluid sample. The sampler comprises a body defining a first chamber, a second chamber, a third chamber and a sampling port therein. The sampling port is in communication with the first chamber and with an outside zone outside the body. The second and third chambers are initially isolated from one another by a control valve. Upon activating the control valve, fluid may flow from the second chamber to the third chamber through a flow restriction. An extendable floating piston is disposed between the first and second chambers, and the floating piston defines a variable volume therein. An initial amount of well fluid flows into the variable volume, thus trapping dirty fluid, and subsequently, a well fluid sample is flowed into the first chamber. An isolation valve is provided for allowing hydrostatic pressure into the sampler after the fluid sample has been taken.

Abstract: A multi-zone screenless well fracturing method and apparatus which allows multiple zones in a well to be treated with one trip of the apparatus into the hole. The apparatus includes a tool string generally comprising a crossover, a packer below the crossover, and a concentric wash pipe extending below the packer. The crossover has a first portion in communication with a tubing string connected thereto and a second portion in communication with a well annulus above the packer. The first portion of the crossover is in communication with the inner wash pipe, and the second portion of the crossover is in communication with the outer wash pipe. The tool string is adapted to stab through a plurality of big bore casing packers which are positioned between adjacent zones. A method of fracturing multiple zones in a well while monitoring conditions at the zone is also disclosed.