Probing while driving for oil well surface profile measurement

Gas/oil well often stretches several miles underground. Due to various extreme conditions such as high temperature, high pressure, and highly corrosive environment, or even land movement due to earthquake, the well will have many possible problems that cause interruption to gas/oil drilling/production, or even accident. Thus one of the frequent well measurements is to check the well deformation, well surface irregularity so that preventive actions may be taken. One major indicator is the circularity measurement as a perfect well has circular casing. In this paper, a novel robot and a built-in well surface measurement method is developed. The robot has a driving mechanism that is capable of moving miles inside a well. A toggle mechanism is designed as both a robot stabilizer and a probe to measure the radius of a point. The current design has four such toggle mechanisms which means four points can be measured at the same time. If needed, the number of measurement points can be easily increased. The proposed system is simple and robust. It can record data while traveling inside a well that stretches miles underground.