Academic literature on the topic 'CONCEPTUAL DESIGN OF A DRILLING HEAD OF A DRILLING RIG'

The paper presents a design concept for an underwater drilling rig which can operate up to a depth of 5000 m below sea level. The proposed main hull of the drilling rig is in the form of a thick-walled toroidal shell, although other possible forms are considered. The proposed primary method of power generation is via a pressurised water nuclear reactor. Considerations are made as to the health and safety of the crew and also to the transport of the retrieved oil.

The purpose of research in the extraction of minerals is the development of technologies that will make it possible to drill wells specially designed for the extraction of ores with a length of several kilometers and a diameter of 300 mm to 2 m. The main research method is an experiment, during which drilling of wells by alternative methods under the same conditions is compared according to a single the selected performance criterion. Drilling of wells with an average length of 1500 meters with an end diameter of 295 mm at a depth of 200 to 400 meters was carried out in soft rocky ground in two alternative ways. The productivity of a directional drilling rig is determined by the efficiency of related interconnected processes,the correlation of which is characterized by graphs, for example, the dependence of the load on the bit on the drilling speed. To calculate the load on the drill pipe, Young’s modulus and the moment of inertia of its section were used. The axial force for drilling the well is determined by calculation using experimental data. By modeling in the EXCEL program, the maximum WOB value was determined. To compare the drilling speeds of a traditional rig and a new generation rig, the speed with a 5 ton bit load and a 15 ton bit load is considered, at which, if other things are equal,the ROP increases three times. The drilling speed of wells with an inclined head of the new technology will be 167 m per day versus 105 m with traditional technology, and the operational productivity of drilling with one rig will be 71 m per day versus 51 m. Universal mobile rack rigs with automatic centering of the drill string and mast in vertical and inclined position and gearless hydraulic drive for rotation and movement of the drilling carriage ensure drilling of wells with a horizontal section length of 1500 meters and a diameter of 300 mm.

Purpose This paper aims to propose a conceptual scale model of mobile drilling robot according to the actual drilling rig and working conditions to improve the safety and automation of drilling in tunnel construction and coal mining applications. Design/methodology/approach A couple of pinion and rack serves as the support mechanism driven by a motor with low rotation speed at high power, and these components are assembled in the center of the robot to tightly fasten the whole body together. The drilling rod and the sleeve are connected through a hole with screw thread so that the rod feeds and rotates simultaneously along with the sleeve. The robot model is automatically controlled by a single-chip microcomputer, and the anti-disturbance circuit is designed as well. A five-step rule obstacle avoidance method is proposed to ensure safe and reliable movement. Findings The results of simulation experiments on drilling operation do indicate that the mechanism and control method are feasible and effective. Research limitations/implications The robot is nearly complete but indeed remains only an experimental machine. Originality/value The design of the mechanism structure for the conceptual robot is novelty. The method of five-step rule obstacle avoidance can improve reliability of obstacle avoidance according to the experimental results, which can meet the requirements of complex working conditions underground coal mine.

With the ever-increasing demand for resources, the task of geological surveys has increased rapidly, and automated geological drilling rigs that can improve the efficiency of geological surveys have become the mainstream research direction. Automated geological drilling rigs can improve construction efficiency, reduce labor intensity, and effectively reduce construction accidents. During the construction of geological survey operations, accidents such as drill breakage, stuck drill, and equipment damage, which are easily caused by drill pipe impact, occur from time to time. Therefore, drill pipe impact dynamics is currently a hot topic in academic research, but there are few studies that combine automated geological drilling rigs with drill pipe impact. This article starts with the research on the hydraulic system of the power head of the automatic drilling rig and studies the dynamics of the damage of the power head of the drilling rig caused by the impact of the drill pipe by means of hydraulic valve torque limit and closed-loop control of the speed. The oil valve group reduces the reverse torsional impact of the drill pipe on the hydraulic motor. At the same time, the requirements for the selection and pressure setting of the relief valve in the buffer filling oil valve group are proposed. The natural frequency of the relief valve is not less than 20 Hz, and the pressure is set to the working pressure 1.25 times. The effects of shock with or without the buffer filling oil valve group and the oil supply line on the power head motor were compared. The research results of this paper can provide theoretical reference and design basis for subsequent development of automated drilling rigs.

Safety analyses of drilling operations are often written from the perspectives of regulation, economics, industry structure, etc. The ergonomic perspective on safety emphasizes that equipment and operations should be designed in light of human capabilities and limitations. To demonstrate this approach a scenario analysis was performed on records for 134 safety incidents on oilwell drilling rigs. The characteristics of the most critical scenarios were then considered to determine the extent to which the ergonomics of environment, equipment, and work methods might have contributed. Ergonomic data was collected at four drilling sites, including a prototype semi-automated rig. From both ergonomic and safety perspectives, the work situation of operators on a conventional rig floor is most in need of remediation. Mechanical pipe handling would provide the most complete solution to this unpleasant and unsafe environment, its strenuous and over-extending tasks, and the risks inherent in putting people near heavy moving objects. Significant improvements can be made at the detail level and at minimum cost in some tasks. Improvement in other tasks requires basic conceptual changes in rig systems and architecture. To realize their potential, new rig concepts must be carefully and systematically designed, and ergonomics should be considered throughout their design.

Installation loads during 19 commercial horizontal directional drilling (HDD) installations were monitored using new in-hole monitoring cell technology. Fifteen of these installations were part of an 8.3 km section of 203 mm diameter by 4 mm wall thickness steel gas distribution line. The predominant soil type was silty clay, and similar construction practices were employed for all installations. The resistance to pipe advancement within the bore was found to increase in an approximately linear manner, varying from 0.20 to 0.31 kN/m, with a mean of 0.26 kN/m and standard deviation σx = 0.03 kN/m. Local peaks caused by borehole curvature or borehole anomalies were found to dissipate, usually within 10 m, before the underlying linear trend resumed. The remaining four installations were evaluated to determine the relationship between measured pull head load and borehole pressure. The correlation observed provides new insight into the factors that contribute to pulling forces during HDD installations. Based on the findings, a conceptual framework is proposed for an improved HDD design model. The framework outlines two development stages: stage 1, based on tabulated measurements of pulling force per length of pipe inserted; and stage 2, involving significant modifications to an existing prediction model to better represent field conditions.Key words: pipelines, tensile loads, mud pressure, directional drilling, load monitoring, pressure monitoring.

THE THESIS FOCUSES ON A CONSTRUCTION DESIGN OF A NEW DRILLING HEAD DESIGNED TO REPLACE THE ORIGINAL ONE IN A MULTIDRILL HYNDAGA DRILLING RING. THE SUBSTITUTION IS SUPPOSED TO PROVIDE A SOLUTION TO THE SHORTCOMINGS OF THE CURRENTLY USED DRILLING HEAD. THE THESIS ANALYSES PARAMETERS OBTAINED FROM THE MANUFACTURER, NEW PRODUCTION REQUIREMENTS AND PROPOSES TWO TYPES OF MOTORS INNOVATIVE METHODS HAD BEEN IMPLEMENTED IN CALCULATIONS OF CONCEPTUAL PARAMETERS OF THE NECESSARY COMPONENTS. THE OUTCOME IS A NEW F-TYPE DRILLING HEAD.

For the growth of demand for utilization of the vast Japanese Economic Exclusive Zone (EEZ), Ministry of Land, Infrastructure, Transport and Tourism of Japan (MLIT) started the R&D project of offshore platform technologies in 2007. National Maritime Research Institute (NMRI) had developed the integrated design support tool, called “Harmonic design tool” for evaluating economical, safety and environmental aspects of the offshore platforms. The tool conducts conceptual design of offshore platforms for seafloor massive sulphides mining, experimental drilling of methane hydrate, combined application of food and energy production. Using the tool, basic design of semi-submersible rig type platform for experimental drilling of methane hydrate is carried out and optimum hull size, predicted steady environmental forces acting on the platform (current, wave, wind forces), thruster specification for Dynamic Positioning System (DPS) such as required thrust force, construction cost are estimated. The purpose of this paper is to evaluate the feasibility of proposed basic design of the platform aspects of stability and position keeping ability. From results of experiments and numerical calculation, it is confirmed that the basic design of the platform proposed by the “Harmonic design tool” is appropriate.

The environmental policy of EU, acknowledged by the Economics Ministers in June 2001 meeting, establishes a set of priorities. The present paper deals with urgent demands in these fields, with attention on pollution decreasing/removal. A survey of European Topic Centre on Waste, based on partial data only, points out the risk of sewage and leachate contamination of subsoil and waterbed for 13500 landfills. The European Council, in the Directive 97/C_76/01, requests the member states to take the necessary measures to ensure, to fullest practicable extent, that old-landfills and polluting-sites should be rehabilitated. This request is specifically addressed, with the Microdrainage project, EVK4-CT-2002-30012, successfully achieved building the robotic prototype, properly operative from mid 2005. The paper presents the innovative developments undertaken by the project. A new drilling equipment is built, suited for autonomous operation, with fully automatic effectors and rods feeding and with multi-function boring/drilling head, to comply with complex work-task schedules. The mechanical architecture needs proper sophistication, to deal with rods supplying along the micro-tunnel, local buffering to complete the lay-down of a draining line, and mast feeding by the purposely designed arm. The system implementation, thereafter, tackles with the severe technical specifications for the micro-tunnel surroundings, and exacting performance requirements in rig levelling, mast attitude accuracy and work-task sequencing. By this project, the successful deployment of these enabling technologies helped in developing the novel robotic device, capable to solve the de-pollution requirements of the EU environmental policy.

Subsea wellhead systems are exposed to wave induced cyclic loading when a drilling unit connects to the well with a marine riser and a BOP. When connected, access is provided to the well and reservoir, and allows for operations such as further drilling, side tracking or workover. Once the operation is completed, the BOP is disconnected from the well, and the wellhead system is not exposed to cyclic loading any longer. Over the lifetime of a well, a number of such operations take place. A wellhead system is perhaps exposed to a total duration of fatigue loading of up to a year, which comprises a sequence of operations of different durations in different seasons. Fatigue predictions for offshore structures are typically based on statistical average of environmental conditions over a large number of years. This is appropriate for permanent installations exposed to continuous wave loading over the lifetime which is often 20 years or more, since variations in the environmental conditions from one year to another is equally represented in the statistics and experienced by the structure. However, for an operation of short duration, the uncertainty in the environmental conditions for that particular period in that particular year needs to be addressed. The weather during October this year is unlikely to be the same as in October last year, and can also be significantly different from average October weather. Although there exists no standard way of doing wellhead fatigue analysis, a commonly applied approach is to do the analysis in a single plane. This is obviously conservative since the wave direction will vary over time, and the fatigue loading will be distributed more around the circumference of the pipe sections in the wellhead system. Furthermore, the environmental conditions are typically based on statistical average for the month or season when the operation is to be executed, sometimes with some conservatism of including the adjacent more severe month or using annual data. Long crested waves are often assumed. This paper address the effect of the uncertainty in the environmental conditions on the accumulated fatigue damage for single and sequences of operations of different durations at different times of the year. A drilling rig in the North Sea has been analyzed using 56 years of hind cast data of significant wave height, peak wave period and main wave direction. Statistics of the fatigue damage rates are calculated and used in a structural reliability analysis in order to estimate reasonably but not overly conservative factors that are to be multiplied with the fatigue damage estimated in a conventional design analyses. Results based on long crested and short crested sea are calculated. An annual variation factor is proposed to account for the variability from one year to another. Secondly, a directional effect factor is proposed to account for the directional variations and its uncertainty on fatigue. Both factors are first estimated considering a single operation only, where the duration is varied between 3 days and up to a year. Thereafter, a sequence of operations of different durations at different times of the year is analyzed, and it is proposed how to consider the accumulated duration of such sequences compared to a single continuous operation. The expected result is an annual variation factor which is greater or equal to unity and a directional effect factor which is less than unity, both with lower values the longer the duration. The product of the two is a quantification of the degree of conservatism associated with a deterministic design analysis using long crested head sea and statistical average omnidirectional weather for the planned drilling operations.

The conceptual design of floating ship shape platform for well maintenance, survey and workover in prospective fields of Russian Arctic and Sakhalin Island shelf (further The platform) was developed by Krylov State Research Centre specialists with the assistance of CDB “Korall”. The platform under design intended for operation in the Arctic conditions and designed to resist the ice formations such as continuous thin first-year ice and broken ice being the first one in the world practice. The form and chosen hull ice strengthening class allow ensuring safe operation in the mentioned ice conditions. The main purpose for development of the platform was to minimize the offshore wells downtime providing the cost effective way for maintenance of subsea production systems comparing with floating drilling rigs and drilling vessels that takes a significant investment. The economic assessments have shown that operation of such platform will cost two to three times less than renting of a rig or drillship. Having the working deck space of about 1,000 m2 and the ability to download a variety of equipment the platform can perform a variety of testing and wells repairing procedures both for underwater wellhead and for wells operated on fixed platforms.

Railroad signaling systems are a vital part of the national railroad that detect trains on the track, identify track fractures, prevent derailments, and alert signal crossing stations when a train approaches. Failures in the signal wire attachments (studs) to rail create uncertainty in the system resulting in reduced train speeds, additional inspection and reinstallation costs, which translate into train delays, downtime, lost productivity and lost profitability for the railroads. Current methods of attaching studs to rails appear to exceed the critical (phase transformation) temperature in the rail material. There have been cases where this has resulted in formation of martensite in the stud-to-rail bond area during cooling. A brittle phase like martensite can produce fractures when stress is applied. Additionally, liquid metal embrittlement has been found in weld joints that involve the use of a brazing compound or solder to attach a signal wire. Methods that involve drilling for a plug attachment through the neutral axis of the rail result in decreased but acceptable fatigue performance. In an effort to avoid damage to the rail, studs have been moved from their ideal location (on the side of the rail head) to the middle of the web, close to or at the rail neutral axis. However, this location for studs causes other problems — wires and studs are highly prone to interfere with maintenance-of-way equipment. Under funding from the Federal Railroad Administration, EWI has developed and patented an inertia friction welding (IFW) process that is a field-portable, repeatable, and reliable solution for signal-wire attachments; in addition, the solid-state bonding mechanism provides advantages over the existing bonding solutions. IFW is used to weld a stud of dissimilar metal to rail, which in turn allows a signal wire to be connected. Several weld stud alloys were chosen for process feasibility trials. These trials identified parameters that produced solid-state welds between the stud and rail with no martensite at or near the bond line. Further experimental trials were conducted to define a range for rotational speed and welding thrust load. Repeatability testing was also conducted to ensure that there is no evidence of martensite at or near the bond line after multiple stud weld-remove-and-repair cycles. A conceptual design of a field-portable rail inertia welder, based on EWI’s patented portable inertia welding technology, has been completed. The welder is lightweight and capable of being powered by a small electric motor. Internal timing and process controls can maintain and deliver weld quality. The simplicity of the process will yield consistent joint performance with minimal operator training and a variety of environmental conditions. Research is being conducted to examine the reliability of the process through a series of bending fatigue tests, corrosion tests and in service testing.