Abstract: A free falling drop sub carries an explosive tool such as a shaped charge pipe cutter or well perforator. The drop sub includes an aperture plugging element to isolate an upper pipe string from a lower pipe string. An upper pipe string fluid pressure actuated valve element retained by shear pins is released to admit the upper string pressure against a pressure displaced firing pin. Displacement of the firing pin initiates detonation of the explosive tool.

Abstract: A firing head embodiment of the invention confines a connected capacitance cartridge, explosive detonator, and wireline connection switch within an independent, cylindrical housing tube that is environmentally capped at both ends by threaded closures for secure transport to a well site.

Abstract: A string of drill pipe, for example, is assembled with a severing sub in anticipation of a possible need to cut the string at some point in the operation. The severing sub includes a thin wall tube that links opposite end tool joint bosses. The tin wall tube is easily cut by a shaped charge cutter. Rotary drive torque is transmitted between the sub tool join bosses by a concentric external torque tube having a torque transmitting assembly at each boss. The torque tube connection to the upper boss has an inseparable circumferential shoulder engagement with the boss. The lower boss engagement of the torque tube is axially separable. When the thin wall tube is cut, the upper boss and torque tube is withdrawn from the well with the upper pipe string.

Abstract: A system for positioning a downhole tool along a pipe string, the system having a series of seating subs inserted along the length of the pipe string wherein each seating sub has a seating aperture disposed around its internal periphery so as to form a bore plug seat of smaller diameter than the diameter of the pipe. The seating apertures are given distinctive diameters that are consecutively arranged along the pipe string length so that the aperture diameters decrease with increasing depth. A drop assembly having an aperture plugging diameter selected to pressure seal a selected aperture includes a bore pressure activated by-pass valve and firing head.

Abstract: A portable manway cover handling apparatus comprises a lightweight support unit having a mounting tab secured to a manway stub flange within stub flange bolt holes by stud bolts projecting from expandable mandrel sleeves. A structural support beam is cantilevered from the mounting tab for attachment of a force line pulling machine. A force line from the pulling machine is attached to the manway cover and all manway flange bolts removed except a single loose hinge bolt proximate of the flange bottom. The pulling machine is operated to control the rotation of the manway cover about the hinge bolt to a stable suspension position whereat the manway portal is open.

Abstract: A fluid flow meter is responsive to measured torque force imposed by fluid flow over a static impeller. Exponential torque relationships imposed upon a static torque shaft by fluid flow over a static impeller are linearized by a resilient torque shaft restraint and translated to flow rate values by torque measuring means.

Abstract: A fluid parameter measuring instrument relies upon a torque transmitting member comprising an integrally joined and substantially concentric shaft within a tube to transfer torsional stress across a pressure differential barrier without a penetration aperture seal. On one environmental side of the barrier, a pair of thin wall beams having strain gauges secured thereto are secured proximate of the beam mid-points to the torque transmitting member and the opposite ends to barrier structure. The strain gauges are connected in an electrical balance circuit to measure torque as a function of stress on the beams.

Abstract: A firing head embodiment of the invention confines a connected capacitance cartridge, explosive detonator, and wireline connection switch within an independent, cylindrical housing tube that is environmentally capped at both ends by threaded closures for secure transport to a well site.

Abstract: An overhead opening door lock device for use with existing types of door systems having horizontally hinged panels carried on rollers confined within channeled roller tracks is attached on the interior side of the door and fixes the door in position relative to the roller track. One leg of a U-shaped device is inserted in the hollow interior of a tube that serves as an articulation axis for a pair of hinged panels. The other leg of the U-shaped device penetrates a suitably positioned aperture in the web of the adjacent channeled roller track. A shear pin or padlock shank may be inserted through an aperture in a tip portion of the other leg that projects past the outside plane of the roller track web.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A portable manway cover handling apparatus and method comprises a lightweight support unit having a mounting tab secured to a manway portal flange within portal flange bolt holes by stud bolts projecting from expandable mandrel sleeves. A structural support beam is cantilevered from the mounting tab for attachment of a force line pulling machine. A force line from the pulling machine is attached to the manway cover and all manway flange bolts removed except a single loose hinge bolt proximate of the flange bottom. The pulling machine is operated to control the rotation of the manway cover about the hinge bolt to a stable suspension position whereat the manway portal is open.

Abstract: A while-drilling Vertical Seismic Profiling (VSP) data acquisition system utilizing the same seismic shots for three purposes is disclosed. First, the seismic shots provide a means for synchronizing a downhole clock in the VSP receiver to a master clock at the surface, thereby enabling correct determination of seismic travel times. Second, the same seismic shots are also used to communicate commands and other information to the downhole VSP receiver, such commands controlling the actions of the VSP receiver or associated devices. Third, the same seismic shots are utilized for purposes of the VSP survey itself, i.e. determination of seismic travel times, forming of seismic images, and determination of geologic and formation fluid properties using the VSP methods.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A well completion method and apparatus comprises a pipe string having a bottom attached boring bit and scraper. Above the bit at designated well fluid production locations, perforation assemblies are integrated into the pipe string. Each perforation assembly comprises a by-pass circulation mandrel and a perforation gun. The circulation mandrel is secured at opposite distal ends in threaded Y-adapter boxes. The perforating gun is secured in collar bores respective to the opposite end Y-adapters.

Abstract: Controlled Buoyancy Perforating technology for highly deviated and substantially horizontal wellbores may include long perforating guns assembled on a rig floor from a multiplicity of light weight and highly engineered shaped charge carrier joints. Tubular housings for such light weight joints may be fabricated from composite materials having steel transition collars. The collars are designed for an angularly coordinated, bayonet assembly and, in most cases, rapid disassembly. The internal volume of each joint is environmentally sealed by a plurality of O-rings. Sleeves that overlap abutting ends of adjacent carrier joint housings are secured by snap rings. Set screws into the sleeve ring channels release the sleeve from a housing. Individual shaped charge units and cooperative fusing are assembled in a light weight inner loading tube having an alignment collar to secure the angular and axial position of the loading tube relative to the transition collars.

Abstract: Cable connection unions are rapidly replaced in a universal seismic data acquisition-module without opening a main electronic circuitry protective chamber. Different connector types required for the many data transmission cable designs needed to service a wide range of survey conditions are more easily accommodated without exposing primary circuitry to the elements.

Abstract: A network distributed seismic data acquisition system comprises seismic receivers connected to remote acquisition modules, receiver lines, line tap units, base lines, a central recording system and a seismic source event generation unit synchronized to a master clock. One or more high precision clocks is added to the network to correct for timing uncertainty associated with propagation of commands through the network. Seismic receivers and seismic sources are thereby synchronized with greater accuracy than otherwise possible. Timing errors that interfere with the processing of the seismic recordings are greatly reduced, thus enabling an improvement in subsurface geologic imaging.

Abstract: A while-drilling Vertical Seismic Profiling (VSP) data acquisition system utilizing the same seismic shots for three purposes is disclosed. First, the seismic shots provide a means for synchronizing a downhole clock in the VSP receiver to a master clock at the surface, thereby enabling correct determination of seismic travel times. Second, the same seismic shots are also used to communicate commands and other information to the downhole VSP receiver, such commands controlling the actions of the VSP receiver or associated devices. Third, the same seismic shots are utilized for purposes of the VSP survey itself, i.e. determination of seismic travel times, forming of seismic images, and determination of geologic and formation fluid properties using the VSP methods.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.