Device for measuring gravitational acceleration in rotating state and method for measuring and extracting gravitational acceleration in rotating state

Abstract

The invention provides a device for measuring gravitational acceleration in a rotating state and a method for measuring and extracting the gravitational acceleration in the rotating state. The device comprises sensors and a measuring circuit. The sensors comprise the three-axis gravity accelerometers, the reference measurement sensor and the temperature sensor, wherein the three-axis gravity accelerometers are used for measuring acceleration component signals in three orthogonal directions; the reference measurement sensor is used for generating a signal which changes along with rotation and is not influenced by vibration or impact as a reference signal; and the temperature sensor is used for measuring temperature inside the device and used for carrying out temperature compensation on the gravity accelerometer. The measuring circuit collects output signals of the sensors, and carries out related processing with accelerometer components through the reference signal so as to extract gravitational acceleration signals, so that centrifugal acceleration, vibration, impact and other interference generated by rotation are eliminated, and the jam-free gravitational acceleration obtained according to the measuring method can be used for calculating the hole drift angle and tool face angle of a drilling tool in the rotating state.

Description

technical field [0001] The invention mainly belongs to the field of oil drilling measurement while drilling, and in particular relates to a gravity acceleration measurement device and an extraction method in a rotating state. Background technique [0002] Measurement while drilling refers to the process of measuring wellbore trajectory parameters in real time during the drilling process, and using drilling fluid, electromagnetic waves, etc. as media to transmit information to the surface. Measuring-while-drilling instruments are the "eyes" of directional drilling engineers and an essential tool for controlling wellbore trajectory. In the process of directional drilling, the direction information of the drill bit is crucial to the correct drilling. Accurate measurement of the direction of the drill bit can not only ensure the efficient drilling of the target, but also avoid the risk of collision with the adjacent wellbore. Therefore, in addition to the traditional bottom hol...

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Problems solved by technology

But the disadvantage is that it can only be measured intermittently at a certain distance. In practical engineering applications, it is usually measured every 30 meters. The borehole trajectory between the measurement points can only be calculated by mathematical methods, so it is impossible to obtain accurate boreholes. track information

At the same time, due to the static measurement, the drilling operation must be stopped frequently, especially in the directional well section, which seriously affects the drilling efficiency. In addition, the drilling stoppage will also affect the stability of the well wall. torque, which brings a series of problems to drilling safety

In recent years, the development of horizontal wells in unconventional oil and gas resources such as shale gas, fine mining in the late stage of mature oilfield development, and development of thin and ultra-thin (less than 1 meter) oil and gas reservoirs require higher and higher trajectory control accuracy. Intermittent measurement mode with MWD is difficult to meet the requirements

[0004] There is a contradiction between the number of trajectory measurement points and measurement efficiency of the existing MWD system stop-drilling measurement. Dynamic continuous measurement of borehole trajectory has become the development trend of directional drilling measurement. Three-axis gravitational accelerometers are installed near the drill bit to measure the inclination angle and tool face angle, but the measurement accuracy is still far behind that of conventional MWD

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