Teleco Oilfield Services Inc.

Allen Duckworth

Donald S Grosso

Thomas L Gennings

Jean P Buytaert

Derek Barnes

A rotating pulse valve for use in a mud pulse telemetry system is presented. In accordance with the invention, a valve is diametrically mounted in a channel of a segment of a drill string wherein drilling fluids flows. The valve comprises blades which are configured so as to be impelled (i.e., rotated) by the flow of the drilling fluid. An escapement mechanism is employed to restrain the valve in selected positions thereby at least partially obstructing the flow of the drilling fluid which results in generating positive pressure pulses or waves in the drilling fluid in response to downhole conditions.

Rotating pulse valve for downhole fluid telemetry systems

An MWD tool includes a mud pulse generator for operation in an upper section of borehole, a sensor portion for operating close to the drill bit in a deep small diameter section of the borehole and a connector portion running inside the drill pipe for conducting output signals of the sensor portion to the mud pulse generator for subsequent transmission to a receiver at the surface of the borehole.

MWD tool for deep, small diameter boreholes

A method of acoustically trasmitting data signals over a drillstring is presented. In accordance with the present invention, acoustic data is transmitted only during preselected short time intervals thereby avoiding destructive interference caused by the signal being reflected back and forth from the ends of the drillstring. The present invention makes use of the fact that the first reflective wave has to travel three times the length of the drillstring before it can interfere with the original data signal. For example, the time for the first wave to travel three times the length of the drillstring can be in the order of one second. Therefore, if the data content of the transmission signal is confined to the first one second or so of transmission, then a transmission channel relatively free of interference is available for data transfer.

Acoustic data transmission method

Downhole measurements are made for accurately determining whether or not a core barrel contains an appropriate amount of core sample before retrieval of the coring tool is attempted. This is accomplished by using a known apparatus for measuring downhole weight on bit (WOB) at the beginning of a coring run to make a first measurement corresponding to the weight of all drillstring components suspended below the measurement point at a selected depth. Thereafter, the coring tool drills down the length of the core barrel. When sufficient drilling takes place to obtain a core, the drillstring is pulled up to the same depth as the measurement and a second measurement is taken. After correcting the data for temperature changes, the difference in between the first and second measurements is obtained and compared to a calculated weight for a full core. If the difference in measurements is less than the calculated full core weight, then it is known that a full core has not been obtained and the coring operation is continued. However, if the difference in the measurements does correspond to the calculated weight of a full core barrel, then the drillstring is retrieved and the acquired core sample is obtained.

Method of monitoring core sampling during borehole drilling

A device for detecting and sensing the boundaries between differing rock strata is provided. This device utilizes electrical conductivity or resistivity to detect and measure the boundary layer. The device of the present invention may be used with a 'measurement-while-drilling' (MWD) tool, using either wire-line or wireless data communication with a surface receiver. Moreover, the resistivity or conductivity detection device of the present invention may also be used alone or in conjunction with gamma radiation sensors. The present invention utilizes at least a pair of electrodes which occupy a small area and are located on one side of the tool aligned with the longitudinal axis thereof. Thus, in drilling a well along a specific formation stratum (which may be horizontal or inclined), the present invention will act to indicate to the driller whether the drill bit is approaching a stratum boundary, and in which direction that boundary lies. With this information, the driller can take appropriate action to change the direction of the well bore as necessary to achieve the preselected and desired path.

Resistivity sensor for generating asymmetrical current field and method

A vibration isolator and shock absorber device is presented wherein elastomeric vibration isolation elements interact with reaction elements to form differential springs, i.e., springs in which the deflection and load characteristics change with load. In the present invention, the load characteristics change from shear at low loading to compression at high loading, with a smooth transition between shear and compression.

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Middlefield, CT, United States of America

Allen Duckworth