Abstract: Voids adjacent a wellbore wall and in a region surrounding a wellbore wall can be detected by monitoring gamma rays scattered from the fractures. Gamma rays are strategically directed from a tool disposed within the wellbore and to the wall and/or the region. Some of the gamma rays scatter from the voids and are detected with detectors set a designated axial distance from the gamma ray source. In addition to identifying the presence of the voids, the location and size of the fractures/perforations is also estimated. Time lapsed imaging of the wellbore wall can yield changes in the voids that in turn can affect permeability of the well. Examples of the voids include fractures and/or perforations.

Abstract: Fractures at a wellbore wall and in a region surrounding a wellbore wall can be detected by monitoring gamma rays scattered from the fractures. Gamma rays are strategically directed from a tool disposed within the wellbore and to the wall and/or the region. Some of the gamma rays scatter from the fractures and are detected with detectors set a designated axial distance from the gamma ray source. In addition to identifying the presence of the fractures, the location and size of the fractures is also estimated. Based on the location and disposition of the fractures, perforations are formed in the formation to provide communication between the fractures and the wellbore.

Abstract: A gravel pack evaluation tool comprised of a low energy radiation source and multiple directionally-collimated radiation detectors to analyze small, azimuthal segments of a gravel pack. Methods of use are also provided. Collimators and radiation shielding used in conjunction with multiple detector arrays allow an azimuthal segmented view of a gravel pack, particularly at certain defined depths into a gravel pack. Radioactive tracers may be used in conjunction with these tools to produce enhanced images of gravel packs and formations.

Abstract: An autonomous robot performs maintenance and repair activities in oil and gas wells, and in pipelines. The robot uses the well and pipeline fluids to provide most of the energy required for its mobility, and to charge a turbine from which it may recharge batteries or power a motor for additional propulsion. A control system of associated systems controls the robot, enabling the robot to share plans and goals, situations, and solution processes with wells, pipelines, and external control systems. The control system includes decision aids in a series of knowledge bases that contain the expertise in appropriate fields to provide intelligent behavior to the control system. The intelligent behavior of the control system enables real time maintenance management of wells and pipelines, through actively collecting information, goal-driven system, reasoning at multiple levels, context sensitive communication, activity performing, and estimation of the operators' intent.

Abstract: A system and method for monitoring processes in the production of oil and gas uses intelligent software agents employing associative memory techniques that receive data from sensors in the production environment and from other sources and perform pattern matching operations to identify normal and abnormal behavior of the well production. The agents report the behaviors to human operators or other software systems. The abnormal behavior may consist of any behavior of the production processes that is other than the desired behavior of the well. The intelligent software agents are trained to identify both specific behaviors and behaviors that have never before been observed and recognized in the well.

Abstract: A method for determining and reporting a general production state of a gas-lift system for an oil well, the oil well having associated tubing, casing, and gas-lift valves, and wherein sensor signals from the welt and its associated tubing and casing are input into mathematical models. The method comprises the steps of: a) extracting values from the mathematical models that indicate instantaneous states of production; b) supplying the sensor signals and the values to an associative memory agent; and c) using the associative memory agent to associate the sensor signals and the values to generate the general production state.

Abstract: An autonomous robot performs maintenance and repair activities in oil and gas wells, and in pipelines. The robot uses the well and pipeline fluids to provide most of the energy required for the its mobility, and to charge a turbine from which it may recharge batteries or power a motor for additional propulsion. A control system of associated systems controls the robot, enabling the robot to share plans and goals, situations, and solution processes with wells, pipelines, and external control systems. The control system includes decision aids in a series of knowledge bases that contain the expertise in appropriate fields to provide intelligent behavior to the control system. The intelligent behavior of the control system enables real time maintenance management of wells and pipelines, through actively collecting information, goal-driven system, reasoning at multiple levels, context sensitive communication, activity performing, and estimation of the operators' intent.

Abstract: The present invention relates generally to increasing the accuracy of MWD nuclear based measurement systems. Specifically, the present invention provides a secondary measurement system for determining the tool displacement from the bore-hole wall for calculated compensation of nuclear measurement data.

Abstract: A borehole logging method for determining thermal neutron decay characteristics of a formation surrounding the borehole, comprises the following steps. The formation surrounding the borehole is irradiated from a location within the borehole with a burst of neutrons and indications of the concentration of the diffusing thermal neutrons are detected in at least three time gates following the burst of neutrons. Corresponding count rate signals in response to the detected neutrons are produced. Thereafter, the count rate signals are combined in a predetermined manner to separate a characteristic of the thermal neutron decay rate of the formation from associated neutron diffusion characteristics which are monotonically decreasing with time. The steps of irradiating, detecting and combining are then repeated at different depth locations within the borehole and a recording of the rate of decay of thermal neutrons as a function of borehole depth is produced.

Abstract: Methods for measuring thermal neutron decay characteristics of earth formations include the steps of irradiating an earth formation with a discrete burst of fast neutrons, detecting indications of thermal neutron concentration in the formation during a sequence of discrete time gates, determining the zeroth order moment of the indications during the sequence of discrete time gates, and determining the first order moment of the indications during the sequence of discrete time gates, in order to obtain the desired thermal neutron decay characteristic of the earth formation.

Abstract: A nuclear method and apparatus determines the temperature of a medium by injecting fast neutrons into the medium and detecting returning slow neutrons in three first energy ranges by producing three respective detection signals. The detection signals are combined to produce three derived indicia each systematically related to the population of slow neutrons returning from the medium in a respective one of three second energy ranges, specifically exclusively epithermal neutrons, exclusively substantially all thermal neutrons and exclusively a portion of the thermal neutron spectrum. The derived indicia are compared with calibration indicia similarly systematically related to the population of slow neutrons in the same three second energy ranges returning from similarly irradiated calibration media for which the relationships temperature, neutron absorption cross section and neutron moderating power to such calibration indicia are known.