Automatic Rig Research Articles

Study on Dynamics of Hydraulic Control System for Automatic Loading and Unloading of Drill Pipe of Geological Drilling Rig

With the increasing demand for resources, the task of the geological survey is growing rapidly. The automatic geological drilling rig, which can improve the efficiency of the geological survey, has become the mainstream development direction. In this study, the hydraulic control system for the automatic screw up and screw down of an automatic drilling rig is studied. Through the establishment of mathematical models such as the four-way slide valve controlled asymmetric cylinder model, drill pipe thread stress model, and steel wire rope elastic model, the hydraulic valve is used to limit the pressure of the hydraulic cylinder, closed-loop control to control rotation speed, and power head floating to prevent screw damage and realize the automatic control of drill pipe up and down of a geological drilling rig. The hydraulic control system is simulated by AMESim software. The simulation model verifies the mathematical model. It is concluded that the maximum transient force of steel wire rope is caused by the elastic coefficient K of steel wire rope, but the magnitude is independent of K. The transient force is the periodic motion force. The displacement, velocity, and acceleration of load are periodic functions related to time. By installing a small flow load sensing valve, the displacement of an asymmetric hydraulic cylinder can be accurately controlled, and then, the displacement of the drilling rig powerhead can be controlled. The combined action of drill pipe speed and power head displacement is adopted, and the power head displacement is followed by PID control through the feedback value of the drill pipe speed, which can realize the automatic loading and unloading of drill pipe and reduce the damage of drill pipe screw during loading and unloading of drill pipe. The research results of this study can provide a theoretical reference and design basis for the follow-up development of an automatic drilling rig.

Research on the Four-stage Drill Pipe Automatic Conveying System

The four-stage drill pipe automatic conveying system is developed to solve the problem that the capacity of the existed drill pipe conveying system is very limited, which needs workers to add drill pipes frequently during drilling and can’t fit the development of the automatic rig. The four-stage drill pipe conveying path plan of the multidirectional automatic rig is designed based on the general conveying path and the starting point normalization, and operating mechanisms are designed, including the pipe box, the transferring device, the main and the deputy mechanical arm. This plan is helpful to reduce the height of the rig by using the room below the side of the pipe box. According to the mechanism, the conveying path is adjusted adaptively to avoid interference between the conveying system and the rig. It is verified by the theoretical calculation and the model machine test that pipes can be delivered automatically and accurately by the four-stage automatic conveying system.

Research on the Correction of the Linkage Hydraulic System of the Composite Hydraulic Gripper Used in Coal Mine Rigs

The research against the defect that the gripper of the rig using a traditional linkage hydraulic system always clips back to damage drill pipes when the rig starts to rotate is presented. The correcting solution of a kinetic pressure feedback system including a damper and an accumulator is described by establishing the transfer function of the linkage system and analysing major factors making the gripper to clip back. Taking the ZYWL-4000SY automatic rig for instance, the linkage hydraulic system after correction is compared with that of before in simulating analysis and the correcting solution is verified by both lab and field tests. The results show that the corrected gripper works well without hurting pipes and the rig operates in good and stable condition. The theoretical foundation and method are provided to design and test the linkage function of the composite hydraulic gripper of other similar rigs.

Multi‐objective shape segmentation and labeling

AbstractShape segmentations designed for different applications show significant variation in the composition of their parts. In this paper, we introduce the segmentation and labeling of shape based on the simultaneous optimization of multiple heterogenous objectives that capture application‐specific segmentation criteria. We present a number of efficient objective functions that capture useful shape adjectives (compact, flat, narrow, perpendicular, etc.) Segmentation descriptions within our framework combine multiple such objective functions with optional labels to define each part. The optimization problem is simplified by proposing weighted Voronoi partitioning as a compact and continuous parametrization of spatially embedded shape segmentations. Separation of spatially close but geodesically distant parts is made possible using multi‐dimensional scaling prior to Voronoi partitioning. Optimization begins with an initial segmentation found using the centroids of a k‐means clustering of surface elements. This partition is automatically labeled to optimize heterogeneous part objectives and the Voronoi centers and their weights optimized using Generalized Pattern Search. We illustrate our framework using several diverse segmentation applications: consistent segmentations with semantic labels, bounding volume hierarchies for path tracing, and automatic rig and clothing transfer between animation characters.

Automatic drilling control based on minimum drilling specific energy using PDC and WC bits

The drilling specific energy (SEdrill) is a very significant measure of drilling performance. It is directly compatible with cost/metre, because it relates to the amount of energy required to penetrate rock. SEdrill can also be used to quantify the efficiency of rock working processes and to indicate bit conditions, rock strength and rock hardness during drilling. The focus of this study is to evaluate the optimum performance of polycrystalline diamond compact (PDC) and tungsten carbide (WC) bits using a criterion based on maximum feed rate at minimum SEdrill or vice versa . A variety of coal-measure rock types were drilled using PDC and WC bits using a fully instrumented and automatic drilling rig at six different rotational speeds (rpm) and an over range of thrust applied to the bit. The operating parameters of the drill bits were monitored on a computer-controlled logging system during the drilling trials. The control system is used to monitor the drilling speed, the thrust, the power developed at the bit, the feed rate, the distance penetrated and the presence of an adequate amount of drilling fluid. The strategy followed while drilling was to maintain a constant level of power at the bit in order to maximise the feed rate and minimise the rate of bit wear. Extensive laboratory tests have been carried out on the drilled rocks including mineralogical, physical and index properties analysis. Similarities between the rock strength and SEdrill are reported. The destruction specific energy (SEdes) was estimated from the area (integral) under the stress-strain envelope in an unconfined compression test. This method provides a better understanding of the relationships between drilling specific energy, drilling rate and the main mechanical rock character. The relationship of the SEdrill to operating parameters of the bits and the rock properties was evaluated using optimum drilling data.

The effects of welding parameters on ultra-violet light emissions, ozone and CrVI formation in MIG welding.

This paper describes the relationships between ultra-violet emission, ozone generation and CrVI production in MIG welding which were measured as a function of shield gas flow rate, welding voltage, electrode stick-out and shield gas composition using an automatic welding rig that permitted MIG welding under reproducible conditions. The experimental results are interpreted in terms of the physico-chemical processes occurring in the micro- and macro-environments of the arc as part of research into process modification to reduce occupational exposure to ozone and CrVI production rates in MIG welding. We believe the techniques described here, and in particular the use of what we have termed u.v.-ozone measurements, will prove useful in further study of ozone generation and CrVI formation and may be applied in the investigation of engineering control of occupational exposure in MIG and other welding process such as Manual Metal Arc (MMA) and Tungsten Inert Gas (TIG).

A Computer-Based Automatic Flowmeter Calibration RIG

This paper describes a “budget” computer-based, automatic rig for the testing and calibration of in-line Magnetic Flowmeters. The rig was designed and engineered at Rustenburg Platinum Mines out of sheer necessity for an inexpensive but accurate calibration facility where the turn-around time for each test was not more than two days.In addition, the rig was required to process and analyse data and produce automatic calibration certificates. Finally, the rig also had to eliminate human error as far as possible and be relatively simple in operation with a “user-friendly” personality.