What is an Inclinometer While Drilling?

The main function of the inclinometer while drilling is to complete the measurement of inclination angle, azimuth angle, tool face angle and other parameters.

At present, accelerometers and magnetometers are used in the domestic directional drilling process. However, because magnetometers are susceptible to electromagnetic interference caused by various factors, expensive non-magnetic collars need to be installed to improve accuracy. Fiber optic gyroscope is considered to be a substitute for magnetometer to measure downhole, which can significantly improve measurement accuracy. Moreover, the use of strapdown inertial navigation method to calculate attitude and velocity can achieve real-time measurement that magnetic sensors cannot achieve, that is, logging while drilling, which can complete the measurement of parameters including inclination angle, azimuth angle, and tool face angle. The instrument uses a fiber optic gyroscope as the sensor, and the measurement is not affected by the magnetic field. In addition to completing the measurement of conventional wells, it can also achieve high-precision measurement of casing wells and magnetic material disturbing well conditions. The core hardware components of the fiber optic gyroscope while drilling inclinometer are two sensors: fiber optic gyroscope and accelerometer. The focus of the system software is attitude calculation. This part combines the Kalman filter algorithm to process the output discrete linear data of the gyroscope and accelerometer, and then conducts the design and simulation verification of the attitude calculation algorithm, and analyzes and analyzes the error source of the system. Compensation, and finally the upper computer software is designed to display the solution results and draw in real time.

Type

Inclinometer is divided into portable inclinometer and fixed inclinometer, portable inclinometer is divided into portable vertical inclinometer and portable horizontal inclinometer, fixed inclinometer is divided into single axis and double axis inclinometer, the most widely used is portable inclinometer. The inclinometer is a kind of in-situ monitoring instrument to obtain the horizontal displacement by measuring the inclination Angle of the borehole.

Principle

The inclinometer pipe is usually installed in a vertical borehole through the unstable soil layer to the stable formation below. Use the digital vertical motion clinometer probe, control cable, pulley device and reading meter to observe the deformation of the clinometer tube. The first observation can establish the initial section of the inclinometer tube displacement. Subsequent observations show changes in section displacement as the ground moves. During observation, the probe moves from the bottom of the inclinometer tube to the top, pauses at a distance of half a meter and measures the inclinometer. The tilt of the probe is measured by two balanced servo accelerometers. An accelerometer measures the longitudinal position of the groove of the inclinometer tube, that is, the inclination of the plane on which the inclinometer probe is located. The other accelerometer measures the inclination perpendicular to the plane of the wheel. The inclination can be converted into lateral displacement. Comparing the current and initial observational data, it is possible to determine the amount of lateral migration change and show the movement displacement occurring in the formation. Plotting the change in the offset gives a high resolution displacement profile. This profile helps determine the magnitude, depth, direction, and rate of ground motion displacement.

Precautions for the use of inclinometer

Use within the working temperature to prevent vibration, strictly prohibit hitting the bottom of the hole, prevent sudden acceleration of the probe, and strictly prohibit rocking the probe with the cable;

It is forbidden to use wire and metal when tying cable, it is best to use a winch or rope.

Clean probe, clean and dry joint, lubricate measuring wheel and O-ring, pay attention to moisture-proof, clean socket and panel;

After use, it is strictly prohibited to make each connection not separate for a long time, which will cause moisture to remain in the probe for a long time to corrode the joint;

After the test is completed, dry the probe and cable, cover the protective cover, and put the probe into the protective box;

Go back inside, dry the reader and charge the battery;

It is best to allow all joints to air dry indoors.

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