While drilling inclinometer is generally used in oil drilling, coal exploration, Marine oil drilling oil field, such as the current most of the inclinometer is wired inclinometer with drilling, and on the basis of the development of a new type of MWDS wireless inclinometer with drilling, it has to do with wired inclinometer with drilling the main difference is that of underground transmission of measured data in a different way, it is widely used in borehole trajectory measurement construction of highly difficult directional Wells, especially in highly deviated Wells and horizontal Wells, and is composed of steering drilling system with guiding power drilling tools and offshore oil drilling.
There are three main transmission methods for MWD wireless inclinometer while drilling
1. Positive pulse method
The position of the needle valve of the positive mud pulse generator relative to the hole can change the cross-sectional area of the mud flow path here, thus causing the mud pressure to rise inside the drill string. The needle valve movement is realized by measuring data encoded by the probe pipe through the modulator control circuit. Changes in riser pressure are continuously detected at the surface and translated into different measurements through decoding.
2. Negative pulse method
Mud pulse generator need to assemble in special non-magnetic drill collar, open the discharge valve of the mud negative pulse generator, can make the mud inside the drill string by the discharge valve and the discharge orifice flow on the non-magnetic drill collar to borehole annulus, causing the inside of the drill string mud pressure is reduced, the action of discharge valve is encoded by test tube measurement data by modulator control circuit.Changes in riser pressure are continuously detected at the surface and translated into different measurements through decoding
3. Continuous wave method
Continuous generator rotor in mud sine or cosine pressure under the action of wave, encoded by underground test tube measurement data through the modulator system control relative to the angular displacement of the rotor stator make the sine or cosine phase displacement appears on the pressure wave in time, on the ground continuously detect these changes in phase displacement, and through decoding into different measurement data.