Abstract: A downhole telemetry system usable with a subterranean well comprises at least one pressure pulse generator, at least one pressure transmitter located in an internal tube space in the well and at least one pressure transmitter located in a tubing annulus. The system comprises a packer providing hydraulic isolation of the tubing annulus and at least one transmitter located below the packer and responding to at least one physical quantity characterizing a bottom-hole zone. The system also includes a data encoder located below the packer to read out the transmitter located below the packer and to respond to at least one physical quantity characterizing the bottom-hole zone, a pressure pulse modulator to modulate pressure pulses generated by the pressure pulse generator, a surface-mounted data-collection unit to converts the output data of the transmitters and to provide a surface-mounted data decoder with data for analysis.

Abstract: The method relates to the field of hydraulic fracturing of subsurface formations. A mathematical simulation model of a pressure pulse propagation inside a wellbore and inside a fracture is created. Pressure pulses are sent to the wellbore, and the response of the well to the pressure pulses is registered. Then, a bottom-hole pressure corresponding to each pulse is determined. An average fracture width is derived by using the mathematical simulation model of pressure pulse propagation inside the wellbore and inside the fracture, and a ratio between the simulated average fracture width and the determined bottom-hole pressure is determined. The said ratio is extrapolated to a zero-width point, and the closure pressure is determined as the bottom-hole pressure corresponding to the zero width.

Abstract: A downhole telemetry system usable with a subterranean well comprises at least one pressure pulse generator, at least one pressure transmitter located in the internal tubular annulus in the well head and at least one pressure transmitter located in the casing annulus near the well. The system comprises a packer providing hydraulic isolation of the casing annulus and at least one transmitter located below the packer and responding to at least one physical quantity characterizing the bottom-hole zone. The system also includes a data encoder located below the packer to read out the transmitter located below the packer and to respond to at least one physical quantity characterizing the bottom-hole zone, a pressure pulse modulator to modulate pressure pulses generated by the pressure pulse generator, a surface-mounted data-collection unit to converts the output data of the transmitters and to provide a surface-mounted data decoder with data for analysis.