Abstract: In a curve drilling assembly having a mandrel rotatably mounted within a cylindrical sleeve, an apparatus and method of using the apparatus are disclosed for orienting the sleeve of a curve drilling system and for shifting modes of operation of a curve drilling system from a steering mode to a straight drilling mode. The apparatus comprises: a drilling fluid powered blade that is carried by the sleeve for engaging the walls of a curved borehole and inducing counter-clockwise rotation of the sleeve; and a valve, carried within the mandrel, for operating the blade by introducing pressurized drilling fluid from the interior of a drill string connected to the mandrel.

Abstract: A rotary drill bit for drilling a curved subterranean borehole. In one embodiment, the drill bit comprises a side portion, a plurality of cutting elements that produce a lateral force on the drill bit in response to the rotation of the drill bit in the borehole, and bearing means. The bearing means is located on the side portion of the drill bit and contacts the borehole wall during drilling to receive a reactive force that is from the borehole, that is in response to the lateral force and that is directed to a location adjacent to the uphole end of the side portion of the drill bit. The reactive force and the lateral force form a downhole-moment that is about the drill bit and that is opposed by an uphole-moment having a force component that is directed at the flexible joint. The uphole end of the bearing means is located relatively close to the cutting elements such that the magnitude of the downhole-moment and the magnitude of the uphole-moment are minimized.

Abstract: An electrical connector assembly 10 provides electrical connection between a surveying tool 53 positioned within a drillstring in a curved portion of a borehole and an electronics package 27 positioned in a vertical portion of the borehole. A non-conductive support 16 of the electrical connector assembly 10 is electrically connected to the surveying tool 53 and passes freely through a tool positioning pipe 18 and an adapter 14 for mounting the non-conductive support in the tool positioning pipe. A receptacle 24 for the non-conductive support 16 is electrically connected to the electronics package 27 for completing a plurality of electronic circuits between the surveying tool 53 and the electronics package when contacts 20 of the non-conductive support establish connection with contact elements 28 of the receptacle.

Abstract: A curve drilling assembly operable with a rotary drill string is provided for drilling a curved subterranean borehole. The assembly includes a curve guide, a rotary drill bit, an imbalance force assembly, and a bearing assembly. The curve guide is connectable with the drill string for deflecting the drill string toward the outside radius of the curved borehole. The imbalance force assembly, which preferably is provided by selectably disposing cutting elements on the drill bit, is rotatable with the drill string for creating a net imbalance force along a net imbalance force vector substantially perpendicular to the longitudinal axis of the drill bit during drilling. The bearing assembly is rotatable with the drill string and is located in the curve drilling assembly near the cutting elements of the drill bit for intersecting a force plane formed by the longitudinal bit axis and the net imbalance force vector and for substantially continuously contacting the borehole wall during drilling.

Abstract: A heating probe and collection assembly is provided for evaluating free hydrocarbons and hydrocarbon potential of whole core. In one embodiment, the one or more assemblies are used with a core transport system to provide measures of hydrocarbon potential as a function of depth.

Abstract: A method of exploring for hydrocarbons is disclosed wherein core is obtained over substantially the entire length of a well and substantially all lithologies represented within the core are analyzed at a core analysis facility located adjacent the well. A measurement of a plurality of physical properties of the core are made promptly after the core is removed from the well. Thereafter, from the measurement of these physical properties, a depth correlated record is generated, and is used (a) to adjust the drilling plan for that well while it is being drilled, (b) used as inputs into other exploration processes, such as seismic surveys, magnetic surveys and gravity surveys, or (c) used for correlation with other depth correlated records obtained from other wells.

Abstract: A method of exploring for hydrocarbons is disclosed wherein core is obtained over substantially the entire length of a well and substantially all lithologies represented within the core are analyzed at a core analysis facility located adjacent the well. A measurement of a plurality of physical properties of the core are made promptly after the core is removed from the well. Thereafter, from the measurement of these physical properties, a depth correlated record is generated, and is used (a) to adjust the drilling plan for that well while it is being drilled, (b) used as inputs into other exploration processes, such as seismic surveys, magnetic surveys and gravity surveys, or (c) used for correlation with other depth correlated records obtained from other wells.

Abstract: A housing includes a liquid crystal display, a keypad and a three ring notebook a plurality of pages therein. Each page includes a plurality of descriptors. A touch sensitive linear potentiometer is affixed to the housing adjacent a page bay into which the book pages can be received one at a time. Data concerning an observed characteristic of a geological core sample is entered into a computer memory by selecting a page and thereafter depressing the strip adjacent the descriptor of interest.

Abstract: A method and apparatus for processing a signal generated by a borehole scanning system of the type in which periodic electrical firing pulses initiate a plurality of corresponding acoustic energy pulses which are transmitted from the central portion of the borehole toward the borehole wall in a plurality of radial directions and at a plurality of different depths, thereby generating reflected acoustic pulses which are detected and converted to electrical pulses. The electrical pulse is periodically sampled with each sample level being converted to a digital number. A counter initiates counting in response to the firing pulse preceding the sample electrical pulse. Upon detection of the peak of the electrical pulse, the counter count is stored. Upon detection of the electrical pulse again falling below a preselected level, the count is again stored. Then the time midway between the two stored counts is determined.

Abstract: A macroscopic and microscopic video record of whole core is stored by translating the core in increments adjacent a video recording station. The core is stopped and movement damped prior to storing the video record for each increment. Overlapping or contiguous macroviews are made using a video camera and in the center of each macroview a microview is also video recorded. The video records are stored in a random access video memory and are retrievable by depth. Macro and microviews of any depth can be instantaneously retrieved and viewed and scanning up or down by depth is also possible.

Abstract: Porosity logs of continuous core are generated using nuclear magnetic resonance (NMR). Core containing naturally-occurring fluids is conveyed between poles of a magnet for NMR analysis. The NMR measures porosity and preferably oil and water saturation and even porosity distribution in the reservoir rock at intervals along the core. The core conveyor, the NMR, and data collection and display are controlled by a processor.

Abstract: A core trough is driven by drive means along a path adjacent analysis means for preliminary analysis of sectioned core taken during stratigraphic exploration.

Abstract: Method and apparatus for logging a borehole of the type in which an acoustic energy signal scans the borehole wall at a plurality of different depths thereby generating signals reflected from a reflecting boundary which are indicitative of the condition of the reflecting boundary. A downhole microcomputer generates a sync signal for firing a transducer thereby directing an acoustic pulse toward the borehole wall. The transducer is rotated by a stepper motor. The computer synchronizes the number of transducer pulses with the number of stepper motor pulses thereby generating a constant number of transducer pulses per motor revolution. Reflected acoustic energy generates an electrical pulse which is amplified and summed with a signal relating to the rotational orientation of the transducer and the occurrence of the transducer firing pulse. The summed signal provides information relating to the condition of the reflecting boundary and may be used to generate a video image thereof.

Abstract: An apparatus and method of use thereof are disclosed herein for determining cement conditions adjacent a casing set within a wellbore. At least one acoustic transmitting and receiving transducer and at least one acoustic receiving transducer are positioned into contact with the interior surface of the casing. At least one pulse of acoustic energy is transmitted into the media surrounding the wellbore from the at least one acoustic transmitting and receiving transducer. Electrical signals are generated in response to acoustic energy received by both transducers from the surrounding media. Representations of the generated electrical signals are recorded as a function of the depth within the wellbore and are indicative of the cement conditions, including the casing-cement bond, the cement-formation bond, cement thickness, and the acoustic velocity associated with the cement.

Abstract: An apparatus and method of use thereof are disclosed herein for determining cement conditions adjacent a casing set within a wellbore. At least one acoustic transmitting and receiving transducer and at least one acoustic receiving transducer are positioned into contact with the interior surface of the casing. At least one pulse of acoustic energy is transmitted into the media surrounding the wellbore from the at least one acoustic transmitting and receiving transducer. Electrical signals are generated in response to acoustic energy received by both transducers from the surrounding media. Representations of the generated electrical signals are recorded as a function of the depth within the wellbore and are indicative of the cement conditions, including the casing-cement bond, the cement-formation bond, cement thickness, and the acoustic velocity associated with the cement.

Abstract: A method and apparatus for processing a signal generated by a borehole scanning system of the type in which periodic electrical firing pulses initiate a plurality of corresponding acoustic energy pulses which are transmitted from the central portion of the borehole toward the borehole wall in a plurality of radial directions and at a plurality of different depths, thereby generating reflected acoustic pulses which are detected and converted to electrical pulses. The electrical pulse is periodically sampled with each sample level being converted to a digital number. Each new digital sample number is compared to the maximum of the preceding digital sample numbers and stored if the new digital sample number exceeds that maximum. A counter initiates counting in response to the firing pulse preceding the sample electrical pulse.

Abstract: Apparatus for creating a video display from information generated by acoustically scanning a reflecting boundary circumferential of a borehole. A downhole tool generates a first signal each time a rotating transducer therein passes through magnetic north. Acoustic pulses emitted from the transducer are radially transmitted toward a borehole reflecting boundary. At least a portion of each pulse is reflected back to the transducer where the same is detected and converted to an electrical pulse representative of the reflected acoustic pulse. The peak of each electrical pulse is detected and the value digitized. A series of different addresses is associated with each digital value from a single 360.degree. borehole scan and the same are accumulated in a RAM with each digital value being stored therein at its associated address. A central processing unit selects a block of video memory locations in a video memory responsive to the magnetic north signal.

Abstract: A hydraulic control system for a downhole sidewall coring tool having first and second power hydraulic systems in which changes in pressure drop in a portion of the first hydraulic system adjusts a control valve to change the pressure in a part of the second hydraulic system. Means are provided to adjust the operation of the control valve as a function of viscosity change in the hydraulic fluid caused by change in ambient temperature.

Abstract: A computer-controlled system for displaying an image of a keratograph taken by a video camera on a video monitor and determining the position/dimensions of the Placido rings on the keratograph, then selectively correcting the measured data. An interface circuit is provided which digitizes and stores in the computer memory one video scan line at a time, and contains ring data storage and logic for superimposing ring data on the keratograph image.

Abstract: A system for transmitting information contained in the form of bits. An encoded signal of two levels of magnitude is generated so that for each data word in the signal, the duration of the encoded signal at one level is equal to the duration of the encoded signal at the second level. The encoded signal is then used to generate a slope signal. It is this slope signal which is transmitted.