An apparatus for generating pressure variances in a fluid flowing in a downhole tool having a longitudinal axis includes a flow section having an outer wall, a flow control member selectively blocking flow in the flow section, and an actuator moving the flow control member between a first position wherein the flow control member at least partially blocks flow in the flow section and a second position wherein the flow control member reduces the at least partial blockage of the flow in the flow section. The actuator may be disposed outside the outer wall of the flow section.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A downhole telemetry method and system are disclosed. In some embodiment, a method includes driving a pulser device based on an input data stream, wherein driving the pulser device includes generating modulated pressure pulses including modulated pulse shapes within a fluid telemetry medium. In some embodiments in which bi-modulation is utilized, the method further includes driving the pulser device including modulating pressure pulses including pulse position modulating pressure pulses.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A drilling fluid telemetry pulser comprises a housing disposed in a drill string in a wellbore, wherein the drill string has a drilling fluid flowing therein. At least one vent valve is disposed in the housing wherein the at least one vent valve is actuatable to vent a portion of the drilling fluid from an interior of the drill string to an exterior of the drill string to generate a negative pressure pulse in the drilling fluid in the drill string. A hydraulic system provides hydraulic power to actuate the at least one vent valve. A downhole controller comprises a processor and a memory in data communication with the processor wherein the memory contains programmed instructions to control the actuation of the at least one vent valve.

An example mud pulse telemetry method includes positioning an external acoustic or vibration sensor on or near a pump to collect acoustic or vibration data during operation of the pump. The method also includes monitoring a pressure of fluid in a tubular, the fluid conveying a data stream as a series of pressure variations. The method also comprises processing the monitored pressure to demodulate the data stream. The processing uses a pump noise estimate obtained at least in part from analysis of the acoustic or vibration data.

Methods and apparatus are disclosed for generating fluid pulses in a fluid column, such as within a well. Various described example fluid pulse generators each have a valve structure including a plurality of rollers rotatable around axes that are oriented perpendicular or otherwise angled with respect to the flow direction, the rollers being arranged to collectively at least partially obstruct the cross-sectional area of the fluid conduit. The rotational positions of the rollers may be varied to change the degree of obstruction in the conduit, thereby to generate pressure pulses in the fluid column detectable at a location remote from the fluid pulse generator; these pressure pulses can be used to encode a signal received at the fluid pulse generator.