Study on Virtual Measurement Technology for Near-Bit Dynamic Forces of Bottom-Hole Assembly

A virtual measurement system for investigating the dynamic behaviors of bottom-hole assembly (BHA) in measurement while drilling is designed and set up. Based on the working principle of system, a straight beam strain gauge sensor device and a virtual instrument-based dynamic force wireless measurement system are developed. The axial force, radial force and torque exerted on rotating simulated drill-string are detected multithreadedly in the laboratory. Then the lateral force is calculated. The dynamic force parameters of BHA composed of simulated drill-strings are measured under different weight on bit loads and deviation angles. The experimental results show that lateral force can facilitate the hole deviation control of BHA due to more sensitivity to weight on bit, deviation angle and BHA combination mode. The proposed measurement technology provides the experimental basis for the theoretical analyses of the hole deviation control mechanism of BHA.