An MWD downhole assistant driller
- and others
Identification of drilling problems is most commonly achieved by simple comparisons of surface and downhole time-averaged measurements of weight and torque, or by shock and vibration sensors located either downhole or at the surface. Various drilling phenomena are more complex than can be described by these simple shock and vibration measurements. The interpretation of drilling vibration data collected at the surface requires specialized expertise, and can be difficult. Sometimes downhole phenomena are not interpretable at the surface. The diagnosis of bottom hole assembly (BHA) vibrations measured directly by a downhole tool is much easier. A prototype downhole assistant driller measurement-while-drilling (MWD) device has been constructed that unambiguously diagnoses drilling phenomena from sensors that are located in the BHA, and that are sampled at a high frequency. Processing algorithms programmed into the prototype identify bit bounce, stick-slip, backward rotation, torque shocks, BHA whirl, pressure anomalies and excessive stress. Drilling efficiency and specific energy at the bit are also calculated. Average weight and torque values as well as drilling diagnostics are transmitted to the surface and enable the driller to make real-time improvements to the drilling process in a timely manner. A key requirement for enhancing drilling performance is the ability to simply and clearly display information about the drilling process on the rig floor. The prototype display not only informs the driller about the severity of drilling phenomena, but also provides advice about how to eliminate particular drilling inefficiencies before they become problematic.
- OSTI ID:
- 166640
- Report Number(s):
- CONF-951002--
- Country of Publication:
- United States
- Language:
- English
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