Abstract: A method and related apparatus for telemetry between downhole devices and surface devices. In particular, the methods and related apparatus may send a first datum of a first parameter in an uncompressed form, and send a second datum of the first parameter in compressed form.

Abstract: The specification discloses algorithms for error recovery in pulse position modulation-based mud pulse telemetry. More particularly, the specification discloses detection and attempted correction of at least five possible error mechanisms: the missed detection of a pulse that creates an interval greater than maximum; the missed detection of a pulse that results in an interval still within acceptable boundaries; detection of an extra pulse; a pulse shift that results in data in contiguous intervals being affected; and a pulse shift resulting in a single interval data corruption.

Abstract: A mud pulse telemetry technique that uses a number of bits per interval based on parameters of the pulse position modulation system in order to reduce data transfer time in a pulse position modulation system. More particularly, depending on parameters of the pulse position modulation such as the minimum-time and the bit-width, it may be possible to decrease overall transmission time by splitting values having a larger number of bits into multiple transmissions with each transmission having a smaller number of bits.

Abstract: The specification discloses algorithms for error recovery in pulse position modulation-based mud pulse telemetry. More particularly, the specification discloses detection and attempted correction of at least five possible error mechanisms: the missed detection of a pulse that creates an interval greater than maximum; the missed detection of a pulse that results in an interval still within acceptable boundaries; detection of an extra pulse; a pulse shift that results in data in contiguous intervals being affected; and a pulse shift resulting in a single interval data corruption.

Abstract: The specification discloses a mud pulse telemetry technique that uses a number of bits per interval based on parameters of the pulse position modulation system in order to reduce data transfer time in a pulse position modulation system. More particularly, the specification discloses that, depending on parameters of the pulse position modulation such as the minimum-time and the bit-width, it may be possible to decrease overall transmission time by splitting values having a larger number of bits into multiple transmissions with each transmission having a smaller number of bits.

Abstract: A drill string having a core sampling device at its lower end is suspended in an earth borehole by a rotary drilling rig at the earth's surface. Drilling fluid pulsations are monitored in the drilling fluid standpipe to generate characteristic signatures of normal coring operations and a precursor, abnormal, signature when the core sampling device first begins to jam, before catastrophic jamming has occurred. Responsive to the abnormal signature, remedial action is commenced, such as reducing WOB, RPM, or terminating the coring operation. The system is also used to determine that an activatable downhole tool has one or more of its parts moved from a first position to a second position.