Abstract: A process for processing a dipmeter curve is shown in the preferred embodiment. In a curve, line segments are drawn between curve minima, a second set of line segments are drawn between minima in the first segments, and this is repeated to desired number of levels. When finished, line segments are numbered and become a branched tree. This tree is reorganized to form an event tree which is easily converted into a stored digital value and is processed for correlation with other curves.

Abstract: A method and apparatus is disclosed for avoiding problems caused by a logging tool sticking in a borehole and subsequently accelerating when it becomes free. Such problems give rise to measurement errors and loss of data, particularly when the tool is in the vicinity of ground discontinuities where the data is especially valuable. In accordance with the method and apparatus, data is stored in the tool as it is moved within the borehole, the data being stored in a manner which varies in accordance with any difference between the actual motion of the tool in the borehole and the apparent motion of the tool as measured at the surface. The stored data is transmitted from the tool to the surface at a rate within a transmission bandwidth capacity of a communication link. According to one arrangement, means are provided for shifting the writing position of data entered into a memory, the shifting means being responsive to an error signal related to any difference between the actual and apparent motions of the tool.

Abstract: A method for laboratory measurement of lithology factor L related to the photoelectric absorption properties of a rock sample for use in lighology determinations. By definition L=(.sigma..sub.T- .sigma..sub.C)/.sigma..sub.C where .sigma..sub.C is the Compton cross section .sigma..sub.T is the total photoelectric cross section of the sample which includes the binding-energy corrected Compton cross section and the Rayleigh photoelectric cross sections. A low-energy source of gamma radiation sensitive to photoelectric absorption and a high energy source of gamma radiation that has a significantly different sensitivity to photoelectric absorption are employed and the attenuation of radiation from each source is measured. With the low energy source, radiation count rates N.sub.L and N.sub.Lo obtained for measuring attenuated radiation with the sample present and with the sample absent, respectively, and similar count N.sub.H and N.sub.Ho are obtained for the high energy source.

Abstract: In a formation tester constructed with an extendable probe driven by hydraulic means, the means being connected to a hydraulic circuit, an improved apparatus is set forth which includes a hydraulic fluid multiplier means. This multiplier means is connected between the pump and the means extending the probe and backup shoes. The multiplier means incorporates a step piston and a large cylinder having a step conforming with the piston. Suitable seals are placed on the piston. The piston drives initially to deliver a high volume low pressure flow to extend rapidly the probe, and completes its operation with a low volume high pressure flow to assure proper setting. This enables more rapid operation and more rapid completion of formation testing.

Abstract: A method and apparatus for drill pipe conveyed logging is disclosed. In a highly deviated well borehole, the apparatus comprises a hollow housing for surrounding a logging tool, lockable and releasable rotating connector joined to said housing, and weights along one side to rotate said housing against or relative to the low side of the deviated well bore. The rotating connector includes a telescoping sleeve, and can move downwardly to lock abutting shoulders, or move upwardly to permit logging tool rotation. A nonconductor housing rotatably locks with a hollow nut and compressed rings. The housing has aligned SP electrode windows aligning with SP electrodes to operate through the housing. A male wet connector enclosed in a sealed capsule is affixed at the top end of the housing and is electrically connected to the logging tool. A cooperative female wet connector in a similar closed capsule is supported on a logging cable.

Abstract: In an acoustic well logging apparatus including one or two transmitters and having a pair of spaced apart receivers, two interval transit times are measured independently through a common zone of interest. The two independent measured values are then compared and the difference is then used in contrast with a threshold determinant based on the period of the transmitted pulses. This comparison shows a difference. If the threshold value is not exceeded by the difference value a quality indication is then obtained suggesting that the acoustic measurements did not suffer from cycle skipping. If the threshold value is exceeded by the difference value, then a possible cycle skip exists. If testing shows that a cycle skip does exist, then the error that it introduces is removed from the final log, and a quality indication is obtained suggesting that the answer is good and that a cycle skip error has been removed.

Abstract: For use in a formation testing tool adapted to be lowered into a borehole on a logging cable, apparatus is set forth which conducts formation measurements including extension of a snorkel into a formation of interest, initiating a drawdown beginning at a first time and terminating at a second time. The flow rate in the drawdown is measured. The present apparatus and method further determine a Horner Plot for that particular formation, and measure the slope of the Horner Plot and also extend the Horner Plot to thereby obtain the intercept representative of final formation pressure after build-up. A relationship is evaluated, and computer circuitry for determining permeability responds to the slope of the Horner Plot, formation fluid viscosity, pretest flow rate and formation thickness to yield permeability.

Abstract: A flex joint for an elongate oil tool which permits flexure and bending while yet protecting electrical conductors is disclosed. The duplicated flex joint incorporates a hollow knuckle having a passage therethrough received in a mating and confining socket terminating in a passage. The knuckle and socket form a flex joint. The flex joint is pinned so that rotation in a conic angle is permitted while rotation of the two components relative to one another is forbidden. The passage is periodically closed by means of a transverse plug, an electrical feedthrough permitting electrical conductors to extend through said plug. The passage is further protected from the intrusion of fluids from the well borehole by means of a spring loaded piston compensating pressurized sealed oil system which operates in an annular space on the exterior of the passage.

Abstract: An optical rotary joint for use in a well logging cable is set forth in the preferred and illustrated embodiment capable of transferring two or more data streams traveling along two or more optical fiber channels. The rotary joint is constructed with a stationary portion and a coacting rotary portion. A first channel of data is delivered to an optical fiber transmitted coaxially of the stationary and rotary sides of the apparatus, transfer across the rotational plane between the two components being accomplished by opposing centrally located, concentrically arranged, coacting optical lenses. A second data channel transmitted through a second optical fiber is delivered to a lens system which converts the light into a cylinder of light coaxial with the first channel and which surrounds the optical management for the first channel. All channels other than the first channel thus are converted into coaxial hollow cylinders of light.

Abstract: For use in a gun supporting a bullet for obtaining a core sample therein wherein the bullet is received in a chamber in the gun, a retrieval cable connecting between a pair of studs for threading to the bullet and gun, the cable being coiled to enable the cable and heads of the stud to be received in a sacrificial plastic cylindrical housing. An electrical flow path is also provided by means of a conductor optionally positioned adjacent an exploding cap and extending to an electrically isolated ground terminal. The ground terminal connects with ground through a compressed spring extending through the housing for contact against the ground.

Abstract: The present disclosure is directed to a motor driven magnetically clutch connected turbine on a sonde adapted to be lowered in a well borehole for measuring fluid flow velocity in the well. The turbine is sourounded by a perforated cage or housing which permits fluid flow to impinge on the turbine and thereby change the speed of rotation of the turbine. The turbine is driven at a first speed dependent on magnetic clutch connection from the turbine to a motor. The turbine speed is changed depending on fluid flow velocity in the well, and such changes are reflected in changes in operating conditions of the motor which powers the turbine at the first speed. Measurement of such changes yields fluid flow velocity.

Abstract: A method and apparatus (43) are disclosed for natural gamma ray spectral logging of a well borehole (41) to determine the abundances of uranium (U), potassium (K), and thorium (Th) gamma rays in the earth formations (46) adjacent to the borehole (41), and for compensating for borehole attenuation effects upon such gamma photons caused by scattering and absorption phenomena in the materials (42) within the borehole.

Abstract: A method for determining the mean depth of penetration of one or more radioactive tracers injected by a hydraulic fracturing process into a fractured formation disposed about a well bore as an indication of the extent of radial fractures including the steps of measuring with a radioactivity detector in the well bore at the depth of the formation fracture, the degradation of the gamma ray energy spectra of the radioactive tracer in the fractured formations resulting from the traverse of radiation through the formations and borehole to the detector; obtaining a ratio C.sub.A /C.sub.B of the count rates C hd A and C.sub.B in two energy ranges where the range for obtaining C.sub.A is sensitive to primary radiation reaching the detector without Compton scattering and the other region for obtaining C.sub.B detects radiation degraded through Compton scattering collisions. The ratio C.sub.A /C.sub.