Dynamic Measurement of Spatial Attitude at Bottom Rotating Drillstring: Simulation, Experimental, and Field Test

Abstract

In the oil and gas drilling engineering, measurement-while-drilling (MWD) system is usually used to provide real-time monitoring of the position and orientation of the bottom hole. Particularly in the rotary steerable drilling technology and application, it is a challenge to measure the spatial attitude of the bottom drillstring accurately in real time while the drillstring is rotating. A set of “strap-down” measurement system was developed in this paper. The triaxial accelerometer and triaxial fluxgate were installed near the bit, and real-time inclination and azimuth can be measured while the drillstring is rotating. Furthermore, the mathematical model of the continuous measurement was established during drilling. The real-time signals of the accelerometer and the fluxgate sensors are processed and analyzed in a time window, and the movement patterns of the drilling bit will be observed, such as stationary, uniform rotation, and stick–slip. Different signal processing methods will be used for different movement patterns. Additionally, a scientific approach was put forward to improve the solver accuracy benefit from the use of stick–slip vibration phenomenon. We also developed the Kalman filter (KF) to improve the solver accuracy. The actual measurement data through drilling process verify that the algorithm proposed in this paper is reliable and effective and the dynamic measurement errors of inclination and azimuth are effectively reduced.

Research on a Measurement Method for Downhole Drill String Eccentricity Based on a Multi-Sensor Layout

“…As shown in Figure 6 , the sensor used for measuring along the drilling calipers is an ultrasonic sensor [ 27 , 28 , 29 ]. The ultrasonic sensor we selected operates at 250 kHz, and when the instrument is operating the sensor sends a series of acoustic pulses to the borehole wall.…”

Dynamics of Mechanical Automatic Vertical Drilling System With a Novel Hydraulic Balanced Turbine

“…Currently, there are mainly three kinds of typical VDS tools, including the Baker Hughes Verti-Trak system, Schlumberger Power-V system, Halliburton Sperry-sun V-Pilot system [2,6,8]. All of them have sensitive and expensive electronic components [9] which has low reliability under complex conditions such as high temperature (more than 200℃) and extreme vibration in ultra-deep wells [10][11][12][13]. In recent years, the Mechanical Automatic Vertical Drilling System (MVDS) [14][15][16] which working in full mechanical mode and more economical, safety and reliability has gradually attracted attention.…”

Experimental Study on the Insulation Layer Thickness of a Novel Ice Coring Device in Loose Sandstone-Type Uranium Deposits

“…Obtaining the core samples of the target strata is especially important to develop uranium resources better. The obtained core can be used to reflect the parameters of the strata lithology, and the parameters can evaluate resource reserve and determine exploration value [4][5][6][7]. The primary uranium deposits in China are sandstonetype, granite type, and silicate type, of which 43% are sandstone-type.…”