A flow-off telemetry system and method of communicating information from a downhole location in a borehole to a surface location while fluid circulation is off. A string is conveyed in the wellbore to define an inner bore and an annulus. During a flow-off condition, an inner bore sealing element closes the inner bore to create a first standing column of fluid in the inner bore, and an annulus sealing element closes the annulus to form a second standing column of fluid in the annulus. A bypass valve in the string at a downhole location between the first standing column of fluid and the second standing column of fluid is activated to generate a pressure pulse including information for performing an action. The pressure pulse is received at a pressure sensor at the surface location and a controller performs an action in response to the information in the pressure pulse.

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.

The invention provides a mud circulation system for reducing swab pressure while tripping out, including drilling tool components, a normal drilling circulation channel and a tripping circulation channel, the drilling tool components include a drill string, a drill bit, and a top drive, the normal drilling circulation channel includes a first rotary valve, a solid phase control device, a mud tank, a mud pump, and a forth rotary valve connected in sequence, the tripping circulation channel includes a second rotary valve, a tripping mud pump, a tripping mud tank and a third rotary valve connected in sequence; the mud circulation system for reducing the swab pressure is operated to: shut down the mud pump, close the first rotary valve, and open the second rotary valve and the third rotary valve before tripping out; determine the pumping flow rate according to relevant parameters.

The invention provides a mud circulation system for reducing swab pressure while tripping out, including drilling tool components, a normal drilling circulation channel and a tripping circulation channel, the drilling tool components include a drill string, a drill bit, and a top drive, the normal drilling circulation channel includes a first rotary valve, a solid phase control device, a mud tank, a mud pump, and a forth rotary valve connected in sequence, the tripping circulation channel includes a second rotary valve, a tripping mud pump, a tripping mud tank and a third rotary valve connected in sequence; the mud circulation system for reducing the swab pressure is operated to: shut down the mud pump, close the first rotary valve, and open the second rotary valve and the third rotary valve before tripping out; determine the pumping flow rate according to relevant parameters.

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 flow-off telemetry system and method of communicating information from a downhole location in a borehole to a surface location while fluid circulation is off. A string is conveyed in the wellbore to define an inner bore and an annulus. During a flow-off condition, an inner bore sealing element closes the inner bore to create a first standing column of fluid in the inner bore, and an annulus sealing element closes the annulus to form a second standing column of fluid in the annulus. A bypass valve in the string at a downhole location between the first standing column of fluid and the second standing column of fluid is activated to generate a pressure pulse including information for performing an action. The pressure pulse is received at a pressure sensor at the surface location and a controller performs an action in response to the information in the pressure pulse.

A flow-off telemetry system and method of communicating information from a downhole location in a borehole to a surface location while fluid circulation is off. A string is conveyed in the wellbore to define an inner bore and an annulus. During a flow-off condition, an inner bore sealing element closes the inner bore to create a first standing column of fluid in the inner bore, and an annulus sealing element closes the annulus to form a second standing column of fluid in the annulus. A bypass valve in the string at a downhole location between the first standing column of fluid and the second standing column of fluid is activated to generate a pressure pulse including information for performing an action. The pressure pulse is received at a pressure sensor at the surface location and a controller performs an action in response to the information in the pressure pulse.

The invention provides a mud circulation system for reducing swab pressure while tripping out, including drilling tool components, a normal drilling circulation channel and a tripping circulation channel, the drilling tool components include a drill string, a drill bit, and a top drive, the normal drilling circulation channel includes a first rotary valve, a solid phase control device, a mud tank, a mud pump, and a forth rotary valve connected in sequence, the tripping circulation channel includes a second rotary valve, a tripping mud pump, a tripping mud tank and a third rotary valve connected in sequence; the method to operate the mud circulation system for reducing the swab pressure is as follows: shutting down the mud pump, closing the first rotary valve, and opening the second rotary valve and the third rotary valve before tripping out; determining the pumping flow rate according to relevant parameters.

A device and method to measure strain in a work string during completion operations. The device can include a tubular body with multiple recesses in an outer surface, with strain sensors positioned in some of the recesses. The device can include a fluid pulser configured to communicate data received from the strain sensors to a surface controller via fluid pulse telemetry, with the fluid pulser positioned within one of the multiple recesses. The strain sensors can measure compression, tension, and/or rotational torque in the work string and communicate the sensed data to the surface for evaluation. The device can include a through-bore that extends through the body and has a substantially constant inner diameter for delivering a ball through the device to operate other downhole wellbore tools.