Abstract: A well survey system comprising and electronic survey tool for determining the inclination of a wellbore is disclosed herein with methods of use. In some embodiments, the electronic survey tool includes an electrolytic tilt sensor adapted to measure a first tilt angle within a first plane and a second tilt angle within a second plane of the electrolytic tilt sensor. The electronic survey tool also includes a system processor for determining the inclination of the wellbore based on the first and second tilt angles. As such, a drop-in replacement and improvement on a mechanical critical vertical drift (CVD) tool is provided herein. The electronic survey tool of the present invention also improves upon and overcomes the disadvantages of prior art electronic survey tools. Due to the stability of the improved survey tool over time and with changes in ambient temperature, for example, the improved survey tool does not require periodic recalibration or correction of measurements for errors and biases.

Abstract: Apparatus for monitoring vibration of a bottom hole assembly used to drill a well includes at least one accelerometer mounted in the bottom hole assembly to generate data in the form of electrical signals corresponding to the acceleration experienced by the assembly. The computer in the assembly is programmed to collect data from the accelerometer and compute magnitude of the assembly acceleration. Means are provided for selecting from the collected data a value which exceeds a preset level. In one form, when the collected data has a value above a preset level, an alarm signal is sent to the surface so corrective measures can be taken to prevent damage to downhole equipment.