A well screen is composed of a plurality of screen units connected in series. Each of said screen units has a cylindrical connecting section at least at one end thereof and includes a plurality of support rods extending in the axial direction of the screen disposed cylindrically about a section of the screen other than the connecting section at a predetermined interval in the circumferential direction of the screen, and a wire wound on the outer periphery of said support rods so as to form slits...

A drilling apparatus having cuttings removal structure to reduce balling thereof comprising an apparatus body having a connection thereon, and structure for contacting cut potions of the earth formation. The contacting structure may include chip breakers, flexible cables, rotating nozzle assemblies, rotating turbine wheel assemblies, rotating vane assemblies, flails or combinations of these. The apparatus may include elastomeric portions and/or movable potions. The drilling apparatus may compris...

The loading bridge for ramps has a bridge plate having a forward and a rearward end. It is connected with the rearward end to the ramp so as to be pivotable about a horizontal axis. An extension connected to the forward end of the bridge plate is provided and is extendable from an initial position into an extended position for supporting the bridge plate on a vehicle to be loaded and unloaded and retractable from the extended position into the initial position. At least one support leg with an u...

A method is provided for increasing the rate of injection of flooding fluids into injection wells. A slug of polar solvent or a mixture of polar solvent and non-aqueous flooding fluid is injected into the injection well to displace aqueous and hydrocarbon liquids in the rock surrounding the injection well. Thereafter, the solvent is removed from the vicinity of the injection well by flooding fluid. The process may be repeated following each time water is injected into the injection well.

A method and apparatus for drilling and completing a bore hole is disclosed. Generally, the method comprises the steps of positioning a workstring in the well, with the workstring having attached thereto a bottom hole assembly. The bottom hole assembly may contain a bit for rotary drilling a bore hole; and, a drilling motor, operably associated with the bit, for effecting rotation to said drilling means. The method further includes the steps of circulating a fluid in the workstring so that the m...

The present invention comprises an improved method and apparatus for taking core samples, wherein a core drilling assembly driven by a downhole fluid motor is retrievably housed within a drilling tool of larger diameter, and wherein a plurality of cores may be cut and retrieved to the surface by withdrawal of the core drilling assembly by including an extender in the core drilling assembly each time it is brought to the surface and returned to the drilling tool, and sequentially cutting another ...

A multiple blow percussion drill assembly is specially configured to provide significantly increased maintainability and adjustability in the field, thereby greatly extending its service life and usefulness over a wide variety of drilling conditions. Both spring replacement and impact hammer delay time variations are rapidly accomplished by virtue of unique positioning and interactions of the internal components, without the need for dissassembly of the sealed high impact energy portion of the d...

A modular element has an internally hollow body (2) made of plasstic material and exhibiting a parallelepiped horizontally-disposed configuration with a transverse section symmetrically diverging from a top portion (4) to a base portion (5). The opposite end surfaces (9, 11) of the body (2) are respectively provided with a coupling lug (8) and an engagement seat (10) matching the shape of said coupling lug. The coupling lug (8) of each modular element (1) is adaped to be fitted in the engagement...

Apparatus is disclosed for use in placing cement within the annulus between a casing string and a well bore in which the casing string is suspended, such apparatus including a stage collar connectible as part of the casing string and having a packing element mounted thereon and adapted to be inflated into engagement with the well bore, one or more side ports through which cement may be circulated into the annulus above the packer, tubular members or sleeves for opening and closing the ports foll...

A method for the in situ removal of mobilizable contaminants, including volatile and semi-volatile organic compounds, from a contaminated unsaturated zone of primarily porous layers of soil, comprising pulsatilely injecting heated pressurized steam into a first location in the zone in order to heat the soil in the zone, and withdrawing the contaminants under subatmospheric pressure from the soil at a second location in the zone. In specific application, the pulsatile injection of steam is used t...