Abstract: In a multiprocessor system, including a first processor, a second processor, a main memory (otherwise termed a Basic Storage Module - BSM), and a control circuit (termed BSM controls), the first processor may attempt to locate specific data in its cache and fail to locate this data. The first processor will query the cache of the second processor in an attempt to locate the specific data. If the data is located, an indication of the existence of the data in the cache of the second processor is sent and stored in a status register associated with the second processor. As a result, preliminary steps have been taken to "flush" or move the data from the cache of the second processor to the BSM in order for the first processor to utilize the data. However, prior to the flush operation, it is necessary for the second processor to synchronize its clocks with the clocks of the BSM controls. When this synchronization is complete, the data in the cache of the second processor is flushed or moved to the BSM.

Abstract: A method and apparatus for enhancing the resolution of an induction logging tool at a desired depth of investigation comprising receiving an induction signal from the formation corresponding to the desired depth of investigation, receiving a second signal from the formation having no zeroes in the spatial frequency domain and filtering and combining the received signals to provide high frequency signal information from the second signal to augment and enhance the first signal. Additional corrections, such as for skin effect and shoulder effect are also made.

Abstract: An acoustic well logging method and apparatus utilizes a rare earth acoustic transducer to provide low frequency acoustic energy within the borehole, and characteristics of a subsurface geological formation may be obtained, such as the formation permeability by measuring values of the attenuation of the Stoneley waves produced by the rare earth acoustic transducer.

Abstract: A shielded solenoid for use in well logging is disclosed in which a cylindrical or solenoidal coil is provided in a support member. A shield is spirally wrapped about the wall of the support member and the coil. The resulting toroidally shaped shield has its individual turns cut so that no complete electrical path exists in each loop of the shield. Each loop of the coil is electrically connected to a ground ring. The shielded solenoid is capacitively shielded from the borehole environment. The shielding is effective because the shielding conductors are effectively transparent to TE electromagnetic fields generated by alternating current flow in the cylindrical coil and substantially eliminate TM electromagnetic fields generation by such current flow.This abstract of the disclosure is neither intended to define the scope of the invention, which is measured by the claims, nor is it intended to limit the invention in any way.

Abstract: A controlled implosive downhole seismic source having a substantially hollow closed vessel body adapted to be lowered in a borehole and means for selectively causing at least a portion of the vessel body to implode under pressure thereby producing seismic waves.

Abstract: In the representative embodiment of the new and improved apparatus disclosed herein, a downhole tool adapted to be coupled in a pipe string and positioned in a well bore is provided with one or more electrical devices cooperatively arranged to receive power from surface power sources or to transmit and/or receive control or data signals from surface equipment. Unique inner and outer coil assemblies arranged on ferrite cores are arranged on the downhole tool and a suspension cable for electromagnetically coupling the electrical devices to the surface equipment so that power and/or data or control signals can be transmitted between the downhole and surface equipment.

Abstract: The invention concerns a process for measuring the flow as a function of time of the several layers of a subterranean multilayer hydrocarbon-producing formation through which a well is drilled, and for determining the parameters of formation by comparison of trends in well behavior shown by actual measurements with trends in behavior established theoretically. The flow rate contributions of individual layers (1 to 5) are determined from cumulative measurements made above successive layers by a flowmeter (13) moved vertically within a wellbore. Experimental curves are derived that represent the relative variations in time of the flowrates of layers (.DELTA.q.sub.j) or groups of layers in the formation using flowrate measurement points obtained when a total flowrate variation (.DELTA.Q) has been imposed on the well at a given time between two given constant values.

Abstract: The invention relates to a tool for measuring pressure in the annular space lying between casing and the production string of an oil well. The tool comprises two sliding elements, with the first element being temporarily locked in a section of the string constituting a circulating valve and with the second element carrying a pressure sensor which receives the pressure reigning in the annular space via a duct and orifices of the circulating valve after they have been brought into register.

Abstract: A well-logging tool, for use within a well borehole for measuring a characteristic of a flowing fluid therein, is shown to include a housing and a spinner for measuring the flow rate of the fluid. The spinner is disposed within the housing. To divert the fluid into the housing, the housing carries a funnel having a wide end and a narrow end, for sealing the annulus between the well borehole and the housing and for directing the flowing fluid into the housing. The narrow end of the funnel abuts and is attached to the housing. A pump is employed for pumping fluids into an inflatable tubular ring attached to the wide end of the funnel to seal the edges of the funnel against the borehole wall.

Abstract: A method for determining a sonde error characteristic of an induction tool is disclosed. The method includes the step of measuring an electrical characteristic which may be the real or quadrature component of conductivity, at two or more different heights above the earth. The sonde error characteristic is determined as a function of a predetermined relationship between the desired sonde error characteristic and the measurements of that characteristic at two or more different heights above the earth. The method may be performed with the tool disposed substantially parallel to the earth. Alternatively, the tool may be disposed substantially perpendicularly to the earth.

Abstract: A method for layered reservoirs without crossflow in order to estimate individual layer permeabilities and skin factors is disclosed. The method consists of two sequential drawdown tests. During these tests the wellbore pressure and the sandface flow must be measured simultaneously. The permeability and skin factor for each layer are estimated uniquely using measured wellbore pressure and sandface flow rate from these two drawdown tests. The method can be generalized straightforwardly to layered reservoirs with crossflow, and can also be used to estimate skin factors for each perforated interval in a single layer reservoir.

Abstract: In accordance with illustrative embodiments disclosed herein, a formation testing tool suspended in a well on a pipe string includes a valve actuator control system which responds to a command signal having a certain signature. The command signal is applied at the surface to the well annulus, and includes a series of two or more low level pressure pulses which are detected at the downhole tool, each pressure pulse having, for example, a certain peak value which lasts for a certain time. On detection of the command signal, a control system within the testing tool permits selective application of hydrostatic pressure which forces the valve actuator to shift from one position to another, thereby to open or close an associated valve element.

Abstract: A method for determining a characteristic of a subsurface geological formation enhances the vertical resolution of dual-detector measurements by utilizing a continuous calibration factor which is obtained from an environmentally compensated characteristic derived from at least two resolution-matched sensor signals, and from a resolution-matched sensor signal from the near-detector of the tool.

Abstract: Using waveforms or travel time acquired by multitransmitter and/or borehole sonic tools, acoustic velocity (or slowness) is computed for compressional, shear, and Stoneley waves using direct phase determination (DPD), the slowness time coherence (STC) method, and multiple shot processing (MSP). There is a nonzero difference between transmitter and receiver delta-t's (slownesses) when the sonic tool is in the vicinity of a borehole feature, such as a fracture or a borehole enlargement. The amount of the difference, T/R delta-t, for compressional, shear and Stoneley waves depends on the size and nature of the fracture(s). It is possible to determine the height, width, and dip angle of the fracture when the T/R delta-t's are used in conjunction with other model data. It is also possible to distinguish between borehole enlargements and fractures with the method of this invention.

Abstract: The invention relates to a well perforation device comprising a support (25) and encapsulated shaped charges (26) fixed unidirectionally on this support, usually on the back side of a support bar whose front side is to be applied against the casing. Positioning rings (35, 36) are snapped onto the charges (26) at regular intervals along the support (25). These rings have a rounded external surface on which the perforation device can swivel up to a correct balanced position for which the front sides of the charges are applied against the casing (13).

Abstract: An arbitration apparatus for use within a computer system comprises a plurality of individual arbiters arranged in a particular configuration wherein some individual arbiters are higher in the particular configuration than a specific arbiter and some individual arbiters are lower in the particular configuration than the specific arbiter. Each arbiter has a request terminal for receiving access request signals, requesting access to a shared system bus, and an enable terminal for receiving an enabling signal. The enabling signal is generated and energizes the enable terminal of the specific arbiter if access requests are not received by higher arbiters in the particular configuration relative to the specific arbiter. If an access request signal energizes an arbiter and an enabling signal energizes the arbiter, an access grant signal is developed from the arbiter.

Abstract: A first data processing system sends a message to a second data processing system via a modem. A processor of the first data processing system executes the instructions of an encoding algorithm stored in a memory of the first data processing system thereby encoding the characters of the message as the message is sent from the first system to the second system. The processor, in conjunction with the encoding algorithm, encodes the characters of the message by locating unacceptable characters among the acceptable characters in the message, the unacceptable characters possessing more than one meaning and triggering the execution of a function other than the intended function. The acceptable characters do not possess any alternative meanings. A bias code is selected for the acceptable characters and a further bias code is selected for the unacceptable characters. The unacceptable characters are converted into modified acceptable characters.

Abstract: A translator writing system develops a translator program capable of transforming a user's source code into object code. The language of the source code is summarized in a unique form, namely, a Backus-Nauer Form (BNF). This BNF form of the source code is utilized by the translator writing system to transform the source code into object code. The BNF form takes into account the attribute specifications associated with the language of the source code and the interaction of the attribute specifications in the grammar of the language of the source code. The translator writing system includes a valid testcase generator for testing the developed translator program utilizing every possible correct program statement in the language of the user's source code. The translator writing system further includes an incorrect, invalid testcase generator for testing the developed translator program utilizing every possible incorrect, invalid program statement in the language of the user's source code.

Abstract: In a pipelined instruction execution system including a microstore for storing sequences of microinstruction addresses associated with each macroinstruction, a nanostore for randomly storing unique microinstructions, and an execution unit for executing the microinstructions, a no-op/prefetch apparatus, according to the present invention, prevents a microinstruction address, stored in the microstore, from accessing the nanostore and forces a no-op address into the nanostore when the execution unit executes a conditional microbranch instruction. A no-op microinstruction, corresponding to the no-op address, is retrieved from the nanostore and is executed in the execution unit.

Abstract: An inverse assembly method for converting binary executable microprocessor code into corresponding assembly language mnemonics provides for the storage of all the possible binary codes and corresponding assembly language mnemonics in a plurality of tables set up in a decision tree form which corresponds to the format of a user document provided by the manufacturer of a target microprocessor. The instructions and data information contained within the executable code acquired from the taret microprocessor are distinguishably tagged prior to being stored in an acquisition memory. The code from the acquisition memory, in binary or hex form, indexes a primary table which contains a plurality of entries containing a binary value which may have a mask portion, each entry containing a plurality of actions having an optional string to be displayed, optional parameter masks and an optional table to call.