Abstract: An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool.

Abstract: An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool.

Abstract: Method and apparatus for optimizing mud pulse telemetry data rate by processing a sequence of measured pulses to minimize adverse effects of pressure pulse reflections, attenuations and distortions. A downhole telemetry unit cooperating with a sensor and disposed in a MWD or LWD logging tool generates a sequence of pulse within the mud column. The sequence is encoder to represent the response of the sensor disposed within the logging tool. The encoded pulse sequence is sensed at the surface of the earth using a pressure transducer. The output of the transducer yields an electrical signal that is typically attenuated and can contain reflections and distortions. This measured signal output is processed to minimize the effects of pulse reflections, attenuations and distortions thereby yielding a primary pulse sequence that is more representative of the response of the sensor and allowing an increase in mud pulse telemetry data rate.

Abstract: A method for the circulation of gas when drilling or working a well. The method includes the step of pressurizing at least two chambers of a multi-chambered accumulator with inert gas. The chambers of the multi-chambered accumulator are operatively connected to one another and individually or in combination isolatable from each other. The method also includes isolating at least one chamber of the accumulator that has been pressurized with inert gas such that during drilling or working the well the isolated chamber remains pressurized with gas that has not been mixed with well gas returns. Pressurized gas is extracted from one or more of the non-isolated chambers of the accumulator and injected into the well. At least a portion of the gas returns from the well is collected, compressed and delivered to at least one of the non-isolated chambers of the multi-chamber accumulator.

Abstract: An MWD/LWD mud pulser orifice for reducing erosion on the discharge side of the orifice has an upstream conduit, a poppet mounted in the upstream conduit reciprocal with respect to the orifice, the orifice is fixed to the upstream conduit having a flow restriction aperture and a discharge side, and a downstream conduit fixed to the discharge side of the orifice has an inner diameter wall. The flow restriction aperture has a center hole plugged by the poppet when the poppet is moved forth into an engaged position, and axial slots integral with and distal from the center hole. The discharge side of the orifice has a smooth transition taper from the center hole to the inner diameter wall in distal regions (excluding the regions of the axial slots).

Abstract: A directional sensor system that incorporates a single axis sensor element that is manipulated to a plurality of orientations. The resulting responses of the sensor element at these locations are combined to obtain a measure of orientation of the system. The system applicable for determining orientation of instrumentation within a well borehole such as measurement-while-drilling, wireline and tubing conveyed borehole instrumentation. The system can be used in other subsurface and surface applications.