Abstract: The tandem drilling motor includes an upper power section comprised of an upper rotor and stator and a lower power section comprised of a lower rotor and stator. A connector having a flowbore therethrough has one end attached to one end of the upper rotor and another end connected to an end of the lower rotor. The upper and lower rotors have a bore therethrough for the passage of drilling fluid. The flowbore of the connector communicates with the bores of the upper and lower rotor whereby drilling fluid may pass through the bore of the upper rotor, the flowbore of the connector, and the bore of the lower rotor. The drilling fluid exits the lower rotor through a port adjacent its lower end. The connector includes transition bores at each end to avoid turbulent flow through the connector.

Abstract: The method employs standard processing techniques in order to derive and maintain raw data as well as background corrected and shop calibrated data. Specific data from standard processing is used for the Enhanced Vertical Resolution (EVR) processing. The method uses corrected and calibrated data from standard processing. This data is filtered using improved standard processing material matching filters. Density correction factors .DELTA..rho..sub.LONG (or equivalently .DELTA..rho..sub.SHORT) is calculated for the long and short detectors and used in further processing. .DELTA..rho..sub.LONG and .DELTA..rho..sub.SHORT are used to calculate the standard calibrated compensated density .rho.. Enhanced processing begins with the iterative deconvolution and filtering (or smoothing) of .DELTA..rho..sub.SHORT. The background corrected and shop calibrated short density data, calculated during standard processing, is materially matched using an improved EVR filter.

Abstract: A lock assembly includes radially movable engagement or latch members configured to engage a profile within a subsurface nipple, and further includes one or more sealing assemblies. The sealing assemblies are radially expandable by enlarging the interior of diameter of the elements of the sealing assembly, such as by placing a mandrel of relatively enlarged diameter through an internal diameter of elements of the sealing assembly.

Abstract: A decentralizer for a diverter, a centralizing guide bushing and a downhole-deployable locating and orienting subsystem.

Abstract: In one embodiment, an epoxy resin composition is provided comprising: an epoxy resin and a partially reduced aromatic amine hardening agent. In another embodiment, a well treating composition is provided comprising: an epoxy resin; a partially reduced aromatic amine hardening agent; a solid particulate material; and a carrier fluid. In yet another embodiment, a method of treating a subterranean formation is provided. The inventive method comprises the step of placing the inventive well treating composition into the formation.

Abstract: The present invention relates to a method of preparing an encapsulated enzyme breaker and method of use in treating a subterranean formation. An encapsulated breaker is prepared by coating an enzyme on a cellulose substrate. A micron-sized particulate is admixed with the enzyme solution to prevent undesired agglomeration of the substrate. The enzyme solution coated substrate is covered with a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide. The membrane contains imperfections through which an aqueous fluid may pass into the breaker to contact the enzyme and diffuse the enzyme outward from the breaker particle.

Abstract: A bi-directional explosive transfer apparatus for use in connecting and orienting perforating guns in a well. The apparatus includes a connector having first and second housing portions which are pivotally attached to one another. First and second explosive devices in the connector provide a bi-directional explosive path between perforating guns joined by the connector. At least one orienting fin is attached to the perforating guns to position the guns off-center so that they will orient themselves by gravity in a deviated well section. The swivel connection provided by the connector allows the guns to rotate individually as necessary and relative to the other guns. A method of perforating a well using the apparatus is also disclosed.

Abstract: Automated objective crosslink time and crosslink temperature determinations are provided in a method of testing for chemical crosslinking of a fluid. A fluid having a crosslinking agent is placed in a vessel and a paddle is rotated through the fluid in the vessel at substantially a constant rotational speed. A paddle torque parameter is sensed at sequential times and digital signals are encoded to define digital torque data representing values of the sensed torque parameter. In response to stored digital torque data and digital time data, a baseline torque parameter value and a change in the digital torque data representing increasing torque of the paddle are determined. In response to the baseline torque parameter value and the change in the digital torque data, a crosslink time for the fluid is determined. A crosslink temperature can also be determined. This is determined in response to the crosslink time and stored digital temperature data that has been obtained at sequential times.

Abstract: An improved formation testing method for measuring initial sandface pressure and formation permeability in tight zone formations exhibiting formation permeabilities on the order of 1.0-0.001 millidarcies based on pressure transients which occur shortly after the tester enters its pressure buildup cycle and substantially before reaching final buildup pressure. The method makes an estimate of formation permeability based on fluid decompression transients which occur in the formation tester flowlines which occur shortly after the tester begins its buildup cycle. The method further estimates initial sandface pressure based on the change in pressure over time shortly after beginning the buildup phase. The method of the present invention thereby permits accurate estimates of formation permeability and initial sandface pressure to be made relatively early in the buildup cycle, thus substantially reducing the time required to make the pressure and permeability measurements.

Abstract: A method for providing gain stabilization to a nuclear spectroscopy tool by use of gross features of largely invariant spectra. A particle or gamma ray energy spectrum of an earth formation and wellbore are measured. A ratio of the number of particles or gamma rays measured in a first energy window to the number of particles or gamma rays measured in a second energy window is calculated. The gain of the nuclear spectroscopy tool is adjusted as a function of the calculated ratio. The first energy window is selected to span substantially an entire range of measured energies for the spectrum and the second energy window is selected to span an upper range of the measured energies for the spectrum.

Abstract: A system is provided for selectively perforating multiple zones in a well either simultaneously, or in series, having isolation barriers, or packers, located between the perforating multiple zones, without moving the system with respect to the well. The system includes a tubing string which carries at least a first and a second perforating gun. At least a first and a second pressure actuated firing head are associated with the first and second perforating guns, respectively. A first and second packer for isolating the perforating guns from each other. A source of actuating fluid pressure for the firing head is provided, which may be the bore of the tubing string. A first selective communication device is provided for isolating the second firing head from the source of actuating fluid pressure until after the first perforating gun has been fired, and for then communicating the second firing head with the source of actuating fluid pressure in response to firing of the first perforating gun.

Abstract: To determine the tensile breaking force of a selected rod/wrap member weld joint in a metal screen of a tubular sand screen assembly used in downhole oil and gas recovery operations a test specimen, including a single rod segment and arcuate segments of the wrap member welded thereto, is removed from the screen. The removed test specimen is supported between base and cover portions of a specially designed test fixture, and a compressive force is exerted on the fixture to forcibly move the base and cover portions thereof toward one another. Representatively, the fixture is operatively positioned in a conventional spring test machine that exerts such compressive force on the fixture. The base and cover portions of the test fixture are configured such that the compressive force is converted to a tensile force exerted on a selected single rod/wrap weld joints in the specimen, with the spring test machine recording the tensile force exerted on the weld joint at its breakage.

Abstract: An improved mechanical system selectively locks the tester valve of an annulus pressure responsive tester valve in position for an indeterminate number of well annulus pressure cycles. The tester valve also features a multi-range metering cartridge which is operable to meter fluid over a wide range of differential pressures. The metering cartridge provides an adjustable resistance flow path which permits fluid flow across the cartridge. The resistance of the flow path is adjustable by selectively diverting the fluid through a series of fluid flow resistors. Resistance may be increased either by adding a number of flow resistors serially or by adding a single flow resistor which itself provides a greater fluid flow resistance.

Abstract: An aqueous fracturing fluid composition and method for fracturing subterranean formations penetrated by a well bore wherein the fracturing fluid comprises a viscosity breaker that comprises a surfactant and a breaker which is solid at ambient surface conditions and dissolves at temperatures in the formation.

Abstract: The invention provides a new strip carrier assembly for carrying shaped charges, such as is particularly useful in perforating guns as are utilized to perforate oil and gas wells. The strip carrier includes a coupling member which couples adjacent strip carrier members together to form a contiguous assembly, and which further provides mounting system for a shaped charge so as to maintain uniform spacing even across the coupling junction. Additionally, the carrier assembly includes a novel tab assembly which cooperates with a charge carrier housing configuration to provide a single assemblage of parts which is capable of orienting shaped charges in any one of a plurality of desired orientations relative to the carrier strip.

Abstract: The present invention provides corrosion inhibiting compositions and methods whereby protective coatings are formed on metal surfaces. The compositions are basically comprised of a corrosion inhibiting condensation reaction product enhanced by the presence of antimony or bismuth compounds.

Abstract: The invention relates to an apparatus and method for verifying the operability of neutron detectors and associated pulse generating circuits in a neutron logging tool prior to committing the tool to the well borehole. The method comprises the steps of exposing the neutron detectors to a source or sources of gamma rays, determining the rate of detected gamma rays by counting detector output pulses, and comparing the detected rate to an expected value thereby to verify the operations of the detectors. In the apparatus in accordance with the invention, the gamma ray source(s) may be contained inside the tool near or mounted on the detectors themselves. In an alternate embodiment, the gamma ray source(s) may be externally applied to the tool at the surface during verification procedures.

Abstract: The present invention provides methods of cementing the junction of multi-lateral wells whereby the set cement can withstand impacts and shocks without shattering. A cement slurry composition which sets into a high strength impact resistant solid mass is utilized comprised of a styrene/butadiene aqueous latex, a latex stabilizer, hydraulic cement and appropriate cementing additives.

Abstract: The present invention provides lightweight, fast setting cement compositions and methods which can be utilized in performing a variety of well cementing operations. The cement compositions are basically comprised of slag cement, water sufficient to form a pumpable slurry, a gas sufficient to foam the slurry and a foaming agent.

Abstract: A poppet and orifice mud pulser assembly is disclosed for use in an MWD system. The mud pulser is capable of generating pressure pulses in the column of drilling mud of various amplitudes to increase the data rate of the mud pulse telemetry system. The mud pulser includes a piston assembly that positions the poppet with respect to the orifice. The piston assembly comprises part of a by-pass conduit which defines a mud flow path around the orifice. Mud flow in the piston assembly generates a force tending to shut the poppet, because the surface area of the piston A.sub.2 is greater than the surface area of the poppet A.sub.1. Mud flow through the conduit (and thus through the piston) tends to force the poppet into a closed position because the force on the piston is greater than the force on the poppet, because of the greater surface area of the piston. A pilot valve is provided to enable and disable flow through the conduit, thus allowing the poppet to open and close.