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. This method also can enhance the statistical precision of the characteristic without degrading the vertical resolution.

Abstract: In the representative embodiment of the new and improved well bore apparatus disclosed herein, a test valve is arranged to be coupled in a pipe string for positioning in a well bore. When the test valve is arranged to be selectively operated by changes in the well annulus pressure, the apparatus of the present invention includes a first normally-open pressure reference valve that may be operated to trap well annulus pressure in a chamber on the tool body to provide a reference pressure that permits the operation of the pressure-controlled test valve. The apparatus of the invention may include a second normally-open valve which is coupled to the first valve and is operated for controlling communication through a bypass passage between the interior and exterior of the tool body. An annulus pressure-responsive actuator piston coupled to the first and second valves is operated by opening a rupture disc to communicate the well annulus pressure to the actuator piston.

Abstract: In the representative embodiment of the new and improved apparatus disclosed herein, the apparatus, including a core of a specific material, couples a first unit to a second unit. The first unit may, for example, be a downhole tool, the second unit being surface equipment. The first unit may also be a video recorder or television camera, the second unit being a television monitor. The 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 cores of a specific material 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: A multi-valve well testing system adapted to be disposed downhole in a borehole, includes a plurality of valves and a plurality of well tool control systems connected, respectively, to the plurality of valves and further includes an automatic control mode feature. The well testing system includes a controller board which comprises a microprocessor and a read only memory (ROM). The ROM has encoded therein a set of microcode which, when executed by the microprocessor, causes the various plurality of valves in the well testing system to be opened and closed automatically, without intervention from the operator at the well surface. A kickoff stimulus is required in order to begin execution of the microcode by the microprocessor. This kickoff stimulus could include a sensing, by a pressure transducer, of a predetermined bottom hole pressure, or a sensing, by a strain gauge, of a predetermined set down weight of the well testing system.

Abstract: Acoustical coupling is proposed as a means of determining the presence and acoustical impedance of materials behind casing in cementation evaluation. Expressions for computing coupling and attenuation in multi-receiver/transmitter logging systems are analyzed in an exponential model for the spatial decay of elastic wave energy propagating axially along the casing. Amplitude change between transmitter(s) and receiver(s) is separated into a change dependent on coupling into and out of the casing wave, as well as a change related to attenuation along the casing. Coupling which is dependent on geometrical factors such as casing size and thickness, and on distribution and mechanical properties of the material outside the casing, shows principally the mechanical impedance of the material outside. Significantly, the bonding of this material to the casing is not a dominant factor for the coupling. Thus an estimation of cement strength may be made even in the presence of microannulus.

Abstract: In accordance with principles of the present invention methods and apparatus are provided for evaluating the quality of the cement bond in cased boreholes. Acoustic energy is used to excite the borehole-casing-annulus-formation system and the quality of the cement bond is determined by examining the ratios of the signals received by two longitudinally spaced apart receivers supported on a sonde. The acoustic energy is generated by two transmitters symmetrically disposed above and below the receivers along the sonde. The spacings between the receivers themselves and between the receivers and the transmitters are selected so as to enhance the correlation between the ratios of the received signals and the quality of the cement bond log. An additional receiver, supported on the sonde at a small distance from one of the transmitters, is employed to determine the quality of the cement bond in hard formations.

Abstract: A pipelined paralled vector processor decreases the time required to process the elements of a single vector stored in a vector register. Each vector register of a plurality of vector registers is subdivided into a plurality of smaller registers. A vector, stored in a vector register, includes N elements; however, each of the smaller registers store M elements of the vector, where M is less than N. A pipelined element processor is associated with each smaller register for processing the M elements of the vectors stored in the smaller register and storing a result of the processing in a result register. Each of the smaller registers of the vector registers, and its corresponding element processor, comprise a unit. A plurality of units are connected in a parallel configuration. The element processors, associated with each unit, have been loaded with the result, the result being stored in a result register.

Abstract: An inflatable well bore packer element, having inner and outer elastomer plies and an intermediate sheath of reinforcing wires, is secured at each end to a central mandrel by inner and outer annular coupling members. Wedge-shaped gripping members that hold the free ends of the reinforcing wires between facing surfaces of the coupling members are positioned and secured by independently tightened rings. The inner elastomer ply is bonded to the inside of the inner coupling member, and the tip of the inner coupling member is formed with a deformable skirt portion that flexes during packer inflation to oppose extrusion of the inner ply into the reinforcing wire holding area between the facing surfaces. The tip of the outer coupling member is rounded to protect the outer elastomer ply from tearing.

Abstract: A parallel vector processor includes a plurality of vector registers, each vector register being subdivided into a plurality of smaller registers. A vector is stored in each vector register, the vector has a plurality of elements. The elements of the vector are assigned for storage in the smaller registers of the vector register. In the parallel vector processor, assume that each vector register is subdivided into M smaller registers. The first successive M elements of an N element vector are assigned for storage in the M smaller registers of the vector register. An element processor is connected to each smaller register. Therefore, the first successive M elements of the N element vector are processed by the element processors 1 through M. The second successive M elements of the N element vector are assigned for storage in the same M smaller registers. The third successive M elements of the N element vector are assigned for storage in the M smaller registers.

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, such as the formation dip, may be obtained by measuring the amplitude of the shear wave and combining that amplitude with known data comprising a graph of shear wave amplitude plotted against incidence angle at known frequencies.

Abstract: A sonic isolation joint (SIJ) of a sonic well logging tool is disposed between a sonic transmitter section and a sonic receiver section of the tool and attenuates compressional and flexural waves which propagate longitudinally along an axis of the tool when the sonic transmitter transmits a pressure wave into a formation of a borehole. The SIJ comprises a first outer housing, a second outer housing, an inner housing disposed within the first and second outer housings, a first attenuation member disposed between the first outer housing and the inner housing and a second attenuation member disposed between the second outer housing and the inner housing, each of the attenuation members including a plurality of rubber isolating washers, and a plurality of steel washers interleaved with the plurality of rubber isolating washers.

Abstract: Induction logging sonde including transmitter and receiver solenoid coils mounted on a support and axially separated from each other. The support is made of conductive material and comprises at least one first longitudinal portion for mounting the coils and second longitudinal portions on each side of the first portion. At least the first portion has a substantially continuous and axisymmetric outer surface so as to favor the flow of eddy currents around the surface, whereby the electric field on that surface is substantially cancelled.

Abstract: In a preferred embodiment of the new and improved well tool that is described herein, a set of alternate outer tool housings are respectively arranged for carrying a common inner assembly having one or more temperature-sensitive devices. The new and improved set of alternative housings includes a first tubular housing having a solid wall of a steel of sufficient strength and thickness to withstand a predetermined pressure and a second tubular housing having inner and outer tubular members coaxially arranged to provide a hollow wall having substantially equal external and internal diameters as the first housing and which is formed of a steel of sufficiently greater strength than the steel in the first housing so that the second housing will have a design pressure rating about equal to the predetermined pressure.

Abstract: A liquid sample to be analyzed is subjected to a vaporizing step. The vaporized components are submitted to a first separation stage by introducing said components into a packed chromatography column and flowing carrier gas through said column. The effluent of the first stage is passed through a flow dividing chamber. A second separation stage is performed by passing the effluent of the flow dividing chamber to a capillary chromatography column and flowing carrier gas therethrough. After a predetermined period of time, flushing gas is introduced through the flow dividing chamber and flowed through the first-stage packed column in a direction opposite to the original direction of flow while the direction of flow remains unchanged in the capillary column.

Abstract: A transmitter for a sonic wall logging tool contains a piston, the plane of the piston being disposed along the longitudinal axis of the tool. The piston moves, in its entirety, transversely with respect to the tool when an alternating current flows in two coils disposed in magnetic fields created by two mangets. Sonic positive pressure waves are created on one side of the piston, and sonic negative pressure waves are created on the other side of the piston. Shear waves are created in the formation, a positive shear wave being created in the formation on one side of the tool, and a negative shear wave being created in the formation on the other side of the tool.

Abstract: The apparatus of the present invention relates to a down hole tool capable of extraction of valid samples and making pressure measurements useful in calculating formation permeability. The tool incorporates the features of a staddle packing to allow formation fluid specimens to be taken at large flow rates without depressing the pressure below the formation fluid bubble point. When used in combination with a pressure probe the tool is used to obtain meaningful permeability readings in a larger radius area than previously permitted with known dsigns. Additionally, the apparatus of the present invention allows flow control during the creation of the pressure pulse which enhances extraction of valid samples and the permeability determination.

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: Methods and apparatus are described utilizing low frequency tube waves in determining characteristics of formations traversed by a borehole. Data received from three spaced receiving transducers are utilized in formulating quantities representative of complex compressibility of formations as well as loss parameters attributed to formation characteristics. When these two factors are recorded as a function of depth, interpretation is made readily available as to the permeability and rigidity of subsurface earth formations. Data is also provided by way of the present invention to enable interpretation concerning the presence of fractures or cracks in the earth formations. The methods and apparatus may also be utilized to examine the condition of casing in a borehole.

Abstract: An electrical induction sonde for measuring a characteristic of an earth formation traversed by a borehole having improved vertical resolution and excellent depth of penetration. The sonde has two or more transmitter-receiver spacings preselected to provide at least two separate induction signals received from the formation that, when combined, produce a response function indicative of formation physical properties with no zeros in the spatial frequency response function over the frequency domain of interest.

Abstract: An apparatus and method for the measuring the transverse dimensions of a hole such as in an oil well including a sonde on which an electro-acoustic transducer is mounted in an off centered position in relation to the axis of the sonde. This transducer has two opposite active faces so as to simultaneously transmit acoustic pulses in diametrically opposite directions from the sonde. When the sonde is centered in the hole, the transducer picks up the echoes retransmitted by the wall of the hole in the two directions, at different times. A recording is made of these times and preferably also of an indication of the amplitude of each of these echoes to obtain both a diameter measurement and an indication of the condition of the hole surface. Several transducers are provided, superposed and oriented along various diameters distributed around the axis of the sonde.