Apparatus and method for downhole dynamics measurements

摘要

Aspects of this invention include a rotary steerable storing tool having a sensor arrangement for measuring downhole dynamic conditions. Rotary steerable tools in accordance with this invention include a rotation rate measurement device disposed to measure a difference in rotation rates between a drive shaft and an outer, substantially non-rotating housing. A coutroller is configured to determine a stick/slip parameter from the rotation rate measurements. Exemplary embodiments may also optionally include u tri-axial accelerometer arrangement deployed in the housing for measuring lateral vibrations and bit bounce. Downhole measurement of stick/slip and other vibration components during drilling advantageously enables corrective measures to be implemented when dangerous dynamic conditions are encountered.