Life-cycle cost of rotary drilling rigs: Cost control in procurement, operation and maintenance

        In the current booming construction industry, market competition is becoming increasingly fierce, and cost control has become a core element for the survival and development of enterprises. For construction companies, the level of cost management directly affects the profitability of projects and even determines their competitiveness in the market. Among the various cost components, rotary drilling rigs, as key equipment for pile foundation construction, have their full life cycle cost control particularly important.Take a large-scale commercial complex project undertaken by a well-known construction company as an example. The total investment of this project was several billion yuan, and the pile foundation project was carried out using rotary drilling rigs. Initially, due to insufficiently precise control over the procurement cost of rotary drilling rigs, the company chose equipment with relatively high prices but not outstanding cost performance. During the usage period, due to the lack of scientific planning, the equipment was idle for a long time and had a low utilization rate. In the later maintenance stage, due to insufficient attention, frequent faults occurred, and the maintenance costs were high. As a result, the cost of the pile foundation project far exceeded the budget, severely compressing the profit margin         of the project and leading to poor performance in terms of profitability. In sharp contrast, another company, in a similar project, attached great importance to the full life cycle cost control of rotary drilling rigs. From the procurement stage, involving extensive research and careful selection, to the usage stage, with reasonable scheduling and efficient utilization, and then to the maintenance stage, with regular maintenance and timely repairs, every link was strictly controlled in terms of cost. As a result, not only was the pile foundation project completed smoothly, but the cost was also kept within the budget, laying a solid foundation for the high profit of the entire project and enhancing the company's reputation and market competitiveness in the industry.It can be seen that strengthening the full life cycle cost control of rotary drilling rigs can effectively reduce the operating costs of enterprises and improve the profitability of projects. It runs through the entire process from equipment procurement, usage, to later maintenance, and even final disposal. Each link contains space and potential for cost control, which is worthy of in-depth research and practice by enterprises.

Clarify requirements, make precise selections

        Different engineering projects are like distinct stages, each having unique parameter requirements for the "main character" - the rotary drilling rig. In the pile foundation construction of urban high-rise buildings, due to limited site space and complex surrounding environment, a rotary drilling rig with moderate torque, a drilling depth of 30 - 80 meters, and a diameter of 1 - 2 meters is often needed. Such a drilling rig must have flexible maneuverability and precise operating performance to cope with operations in confined spaces and high-precision pile foundation requirements. In large bridge construction, in the face of complex geological conditions of rivers and high requirements for the bearing capacity of pile foundations for large-span bridges, a rotary drilling rig with large torque, such as 300 - 500kN・m, a drilling depth of 80 - 150 meters, and a diameter of 2 - 3 meters is required to ensure that it can penetrate deep cover layers and firmly establish piles in hard bedrock.

        If the selection is inappropriate, it is like asking a sprinter to participate in a marathon, which will inevitably lead to waste of resources and increased costs. Once there was a small residential construction project, mistakenly choosing a large, high-torque rotary drilling rig. This drilling rig not only had a high purchase cost, but also was difficult to operate in the narrow construction site, inconvenient to operate, and consumed much more fuel than expected. At the same time, its powerful functions were completely "overkill" for the simple geological conditions and ordinary pile foundation requirements of this project, resulting in serious waste of equipment resources and greatly increasing the procurement cost and subsequent operating costs of the project. Therefore, understanding the geological conditions of the project, pile type design, and project schedule requirements, and making precise selections based on the actual project conditions is the key first step in controlling procurement costs, just like finding the right pair of crystal shoes for Cinderella, so as to dance lightly on the path of cost control.

Conduct multi-channel research and compare prices from different sources

        In the information age, online platforms have provided us with convenient channels to learn about the prices and performance of rotary drilling rigs. On various engineering machinery websites and industry forums, there are numerous parameters, quotations, user reviews, etc. of different brands of rotary drilling rigs. Through these platforms, we can quickly screen out equipment that meets basic needs and conduct preliminary comparisons of products from different brands and models. For example, on a certain engineering machinery website, one can clearly see the detailed parameters and approximate price ranges of different models of rotary drilling rigs from brands such as Sany, XCMG, and Zongli Heavy Industry. One can also refer to the usage experiences and actual cases shared by other users, thereby gaining a more intuitive understanding of the equipment.

        Attending engineering machinery exhibitions is an excellent opportunity to get close contact with the equipment. At the exhibitions, one can not only see the real displays of various rotary drilling rigs, intuitively feel their appearance, structure, and craftsmanship, but also watch the operation demonstrations of the equipment, understand its actual working performance and efficiency. At the same time, having face-to-face communication with the salespeople and technicians of the manufacturers can obtain the most direct and accurate product information, and also learn about the latest product developments and market trends. For example, the Bauma China (Shanghai BMW Exhibition) held every year, many domestic and foreign well-known brands will showcase their latest rotary drilling rigs, attracting a large number of industry professionals to visit and exchange.

        Consulting peers is also an effective way to obtain real information. Peers have accumulated rich experience in actual use, and their personal experiences and suggestions have extremely high reference value. By participating in industry exchange conferences and joining relevant industry communities, one can establish contact with peers, ask for their experiences and lessons learned in the procurement and use of rotary drilling rigs, understand the performance of different brand equipment in actual work, and the quality of after-sales service of each manufacturer, etc. Through multi-channel research, comprehensively understand the market situation, and be able to select high-value-for-money products from among numerous brands and suppliers, avoiding the cost loss caused by blind purchasing.

Negotiation Skills and Purchase Timing

        Procurement negotiations are like a non-violent war. Mastering certain strategies is crucial. When negotiating with suppliers, it is essential to fully understand the market conditions and the quotations of competitors, so as to have a clear understanding and increase the confidence in the negotiation. The "comparing prices from multiple sources" strategy can be adopted, where inquiries are made from multiple suppliers, and the favorable terms of other suppliers are used as negotiation leverage to force the current supplier to lower the price or offer more concessions. For example, when negotiating with a certain supplier, mentioning that another supplier offers a lower price and a longer warranty period, this can be used to require the other party to make concessions on the price or provide additional services, such as free training for operators or free replacement parts.

        Monitoring market dynamics and seizing the right purchase timing can also effectively reduce costs. During promotional periods, suppliers, in order to increase sales and recover funds, often launch a series of discount activities, such as discounts, price reductions, and gift giveaways. When new products are launched, in order to open the market, manufacturers may also offer certain price discounts or additional services. For example, when a certain brand launched a new rotary drilling rig, to attract customers, not only was a price lower than the average market level provided, but it also promised to provide equipment maintenance and service free of charge within a certain period, which is undoubtedly a good opportunity for the purchaser to reduce costs. In addition, during the off-season of market demand, suppliers have a greater inventory pressure, and at this time, purchasing is more likely to secure favorable conditions.

Optimizing construction plan

        Reasonably arranging the construction schedule and equipment dispatch is the key to improving the efficiency of rotary drilling machines and reducing costs. When formulating the construction schedule, it is necessary to fully consider the actual situation of the project, such as geological conditions, pile position distribution, and the size of the construction site. For areas with complex geological conditions, the construction sequence should be reasonably arranged. Start with the more difficult piles and gradually move to the relatively easier areas to avoid wasting time and resources due to frequent changes in construction sites and equipment debugging.

        In terms of equipment dispatch, different construction stages require flexible allocation of rotary drilling machines. For example, in a large residential complex's pile foundation construction project, at the beginning of the project, multiple buildings are simultaneously conducting foundation construction, and the demand for rotary drilling machines is large. Through reasonable scheduling, multiple rotary drilling machines are arranged in different construction areas of the buildings and operate simultaneously, greatly improving the construction efficiency and shortening the construction period. In the later stage of the project, the pile foundation construction of some buildings is completed, and the construction area decreases. At this time, timely adjusting the equipment dispatch, allocating the redundant rotary drilling machines to other urgently needed projects, avoids equipment idleness and reduces the usage cost of the equipment. According to statistics, through scientific and reasonable construction plans and equipment dispatch, the equipment utilization rate of this project increased by 30%, and the construction cost was reduced by 15%.

Reduce energy consumption

        As a large-scale construction machinery, the energy consumption of a rotary drilling rig constitutes a significant part of the operating cost. Its energy consumption is mainly influenced by the performance of the equipment itself, the operating method, and the construction conditions. The performance parameters such as the engine power and the efficiency of the hydraulic system directly determine its energy consumption level. In terms of operation, frequent rapid acceleration, rapid deceleration, and unreasonable speed control will increase energy consumption. In terms of construction conditions, drilling in hard ground requires more power than drilling in soft ground, and thus energy consumption also increases accordingly.

        To reduce energy consumption, the first step is to select energy-efficient equipment. Some new rotary drilling rigs have adopted advanced energy-saving technologies, such as intelligent speed control technology. Through intelligent programming, the equipment can intelligently control the engine speed according to the operating environment, providing excellent fuel consumption performance regardless of smooth driving, downhill, climbing, or drilling conditions, just like equipping the equipment with a virtual fuel-saving trainer. Secondly, optimizing the operation process is also crucial. Operators should avoid bad operation habits such as rapid acceleration and rapid deceleration and maintain a stable operation rhythm. During the drilling process, reasonable adjustment of the drilling speed and torque according to the ground conditions can avoid excessive force and increase energy consumption. For example, when drilling in soft ground, appropriately reducing the drilling speed and torque can ensure construction quality while reducing energy consumption. In addition, energy conservation can also be achieved by reasonably matching power and load. According to different construction conditions, precisely control the output power of the engine to match the load, avoiding the engine running under high load or low efficiency, and reducing energy waste.

Personnel Management

        Personnel are the key factors in the rotary drilling machine construction process. Their skill levels, work attitudes, and teamwork abilities directly affect the construction efficiency and costs. Regular training for the operators is an important way to enhance their skill levels. The training content should cover equipment operation norms, maintenance knowledge, safety precautions, and energy-saving techniques, etc. Through professional training, operators can master the operation methods of the equipment, reduce equipment damage and construction delays caused by improper operation, and thereby reduce costs.

        A reasonable salary incentive mechanism can fully mobilize the work enthusiasm and initiative of the operators. Linking salaries with work performance, giving corresponding rewards to operators with excellent performance, high construction efficiency, and low energy consumption, such as bonuses, honorary certificates, etc.; imposing appropriate penalties on those who are not serious about work and make mistakes. This can encourage operators to focus more on their work, improve work quality and efficiency.

        Good teamwork is the foundation for ensuring the smooth progress of construction. In the rotary drilling machine construction team, operators, technicians, managers, etc. should closely cooperate. Operators should promptly report the equipment operation status and problems encountered during construction to technicians, and technicians should promptly provide technical support and solutions; managers should reasonably arrange work tasks, coordinate various resources, and ensure construction progress and quality. For example, in a bridge pile foundation construction project, due to the narrow construction site, the parking and transfer of the rotary drilling machine were difficult. Operators promptly reported this situation to managers, and managers and technicians discussed together, formulated reasonable site planning and equipment transfer plans, and organized construction personnel to assist in the equipment transfer, so that the construction could proceed smoothly, avoiding project delays and cost increases caused by site issues.

Preventive Maintenance Plan

    Preventive maintenance is like giving a "precautionary shot" to a rotary drilling rig, which can effectively reduce the probability of failures and ensure the stable operation of the equipment. Formulating a detailed regular inspection plan, clearly defining the time intervals, items, and standards for inspections is the key to preventive maintenance. For example, weekly inspections of key parts of the equipment, such as the engine, hydraulic pump, and motor, are conducted to check for abnormal noises, vibrations, or overheating; monthly comprehensive inspections of the electrical system, including cables, switches, and sensors, are carried out to ensure secure electrical connections and good insulation of the lines, and that the sensors are functioning properly; quarterly non-destructive testing of structural components, such as drill rods, drill bits, and masts, is conducted to check for cracks, deformations, etc. Based on the usage conditions of the equipment and the manufacturer's recommendations, a reasonable plan for replacing wear parts is also very important. For the wear parts of the rotary drilling rig, such as filters, oil seals, and bucket teeth, they will gradually wear or age during long-term use, losing their original performance. Timely replacement of these wear parts can avoid small problems leading to major failures. For example, clogged filters will cause contamination of the hydraulic system, damaging hydraulic components; aging oil seals will cause oil leakage, affecting the normal operation of the equipment; severely worn bucket teeth will reduce drilling efficiency and increase energy consumption. Generally, hydraulic oil filter elements should be replaced every 200 - 500 hours based on the equipment's working environment and the cleanliness of the hydraulic oil; air filter element filters in dusty environments may need to be cleaned weekly and replaced every 1 - 3 months; bucket teeth should be replaced when they reach a certain degree of wear.

        Although preventive maintenance requires a certain amount of time and cost, compared to post-failure repair, it can save a significant amount of expenses. Post-failure repair not only incurs high repair costs, including component replacement costs, labor costs, etc., but also causes equipment downtime, affecting construction progress and causing indirect economic losses. However, preventive maintenance can effectively avoid the occurrence of failures by detecting and resolving potential problems in advance, reducing equipment downtime, lowering maintenance costs, and improving the equipment's service life and economic benefits. According to statistics, implementing an effective preventive maintenance plan can reduce equipment maintenance costs by 30% - 50%.

Maintenance Management

        Choosing high-quality maintenance services is crucial for ensuring that rotary drilling rigs can resume normal operation quickly. When selecting a maintenance service provider, one should consider factors such as their technical strength, service quality, reputation, and price comprehensively. A high-quality maintenance service provider should have a professional technical team that is familiar with the structure, principles, and common faults of rotary drilling rigs, and can quickly and accurately diagnose faults and provide effective solutions. They should also have a complete after-sales service system that can respond promptly to customers' maintenance needs and provide on-site maintenance services to shorten equipment downtime. At the same time, attention should be paid to the reputation of the maintenance service provider, which can be obtained by checking customer reviews and consulting peers. Price is also an important factor, but it should not be the only consideration. Instead, one should comprehensively consider the maintenance quality and service level to choose a maintenance service provider with good value for money.

        Establishing detailed maintenance records is important for equipment maintenance management. These records include information such as the fault phenomena, causes, maintenance time, maintenance content, and replaced parts of the equipment. Analyzing these records can help understand the fault patterns of the equipment and identify its weak points, providing a basis for formulating more scientific maintenance plans. For example, if it is found that the hydraulic system of a rotary drilling rig frequently fails, analyzing the maintenance records may reveal that it is due to the unstable quality of a certain brand of hydraulic oil, causing damage to the hydraulic components. Then, in subsequent maintenance, the brand of hydraulic oil can be replaced, or the inspection and maintenance of hydraulic components can be strengthened, thereby reducing the probability of hydraulic system failures.

        Regularly analyzing maintenance data and summarizing the causes and patterns of faults is an important means to optimize maintenance strategies. Based on the analysis results, maintenance plans can be adjusted specifically, and inspections and maintenance of components prone to failure can be strengthened, taking preventive measures in advance to reduce the risk of faults. At the same time, maintenance data can be fed back to the equipment manufacturer to provide references for product improvement and upgrading, thereby enhancing the reliability and stability of the equipment. For example, by analyzing the maintenance data of multiple rotary drilling rigs, it is found that the engine of a certain model of rotary drilling rig often has problems with the fuel injector. Then, in the maintenance plan, the fuel injector can be inspected and cleaned in advance, or it can be replaced in a timely manner when it reaches a certain service life to avoid engine performance decline or shutdown due to fuel injector failure.

Case Background Introduction

        This large-scale bridge construction project is 5 kilometers long and spans a wide river. The geological conditions of this project are complex, with a thick overburden layer and a hard rock layer beneath. The requirements for the bearing capacity and stability of the pile foundation are extremely high. To meet the project's needs, [Brand Name] of [specific model] rotary drilling rig was selected. This drilling rig has a torque of up to 350kN・m and a drilling depth of up to 100 meters, which can effectively cope with complex geological conditions. The construction site is located by the river, with limited space, and is affected by seasonal water level changes, which poses certain challenges to the construction.

Cost control measures implementation

        During the procurement stage, the project team established a professional research group to conduct in-depth investigations of multiple rotary drilling machine suppliers in the market. Through online platforms, they collected product information, participated in construction machinery exhibitions to understand the performance of the equipment in person, consulted peers to obtain usage experience, and after several months of research and analysis, finally selected three suppliers that met the project requirements. During the negotiation process, the project team fully utilized negotiation skills, based on detailed market research reports, conducted multiple rounds of arduous negotiations with the suppliers on aspects such as price, after-sales service, and spare parts supply. Eventually, they successfully purchased the desired rotary drilling machine at a price 15% lower than the budget, and secured the supplier's commitment to providing two-year free maintenance and maintenance services, as well as the promise to supply spare parts at discounted prices during the first three years of equipment use.

        During the usage stage, the project team utilized advanced project management software to formulate detailed construction schedule plans and equipment dispatch plans. Based on the distribution of bridge pile foundations and the construction sequence, they reasonably arranged the operation time and location of the rotary drilling machine to ensure continuous and efficient operation of the equipment and reduce idle time. At the same time, they provided strict training and assessment for the operators, requiring them to operate strictly in accordance with operating procedures to avoid equipment damage and construction delays due to improper operation. To reduce energy consumption, the project team also equipped the rotary drilling machine with an intelligent fuel consumption monitoring system, which could monitor the fuel consumption of the equipment in real time, adjust the operation mode and construction parameters in a timely manner, and reduce fuel consumption by 10%.

        During the maintenance stage, the project team formulated comprehensive daily maintenance and preventive maintenance plans. After each construction day, the operators would conduct a comprehensive cleaning, lubrication, and inspection of the rotary drilling machine, promptly discovering and addressing potential problems. Professional technicians were scheduled to conduct in-depth inspections of the equipment every week, and a comprehensive maintenance and repair were carried out every quarter. Based on the equipment's usage and manufacturer's recommendations, spare parts were reserved in advance to ensure timely supply when replacements were needed. A detailed maintenance file was established, and the repair records of the equipment were analyzed and summarized each time to identify weak points in the equipment and strengthen maintenance and repair in a targeted manner.

Key Points for Review

        The cost control throughout the entire lifecycle of the rotary drilling rig covers multiple critical aspects such as procurement, usage, and maintenance. In the procurement stage, clarifying requirements and making precise selections is the foundation, while exploring multiple channels and comparing prices are the means, and mastering negotiation skills and seizing the right timing are the key points. Through these strategies, it is possible to effectively reduce procurement costs and select equipment with high cost-effectiveness.

        During the usage process, optimizing the construction plan, reasonably arranging the construction schedule and equipment dispatch can increase equipment utilization; reducing energy consumption, starting from equipment selection, operation procedures, and power load matching, can reduce energy consumption; strengthening personnel management, through training to enhance personnel skills, establishing a reasonable salary incentive mechanism to motivate personnel, promoting team collaboration, thereby improving construction efficiency and reducing usage costs.

        In the maintenance stage, conducting regular maintenance, including cleaning, lubrication, and inspection of key components; formulating preventive maintenance plans, conducting regular inspections and replacing wear parts; strengthening maintenance management, choosing high-quality maintenance services, establishing maintenance files and analyzing data, these measures can effectively reduce the probability of equipment failure, reduce maintenance costs, and extend the service life of the equipment.

Future Trends

        With the rapid development of technology, the application of new technologies in the rotary drilling rig field will bring new opportunities for cost control. The continuous advancement of intelligent technology will enable rotary drilling rigs to possess more powerful intelligent monitoring and fault diagnosis functions. By monitoring the operating status of the equipment and the wear conditions of key components in real time, potential faults can be detected in advance, and timely maintenance measures can be taken to avoid sudden equipment failures that cause downtime losses and high maintenance costs. For example, intelligent sensors can collect various data of the equipment in real time, and through data analysis, potential problems of the equipment can be predicted, providing more accurate basis for preventive maintenance.

        The application of new energy technologies will also have a profound impact on the cost control of rotary drilling rigs. For instance, the emergence of electric rotary drilling rigs offers advantages such as lower energy consumption and less pollution compared to traditional fuel-powered rotary drilling rigs. With the continuous breakthroughs in battery technology, the range and power performance of electric rotary drilling rigs will continue to improve, and the usage cost will further decrease. At the same time, the maintenance cost of new energy equipment is relatively lower, which also helps to reduce the total life cycle cost.

        In terms of new concepts, the in-depth promotion of the green construction concept prompts enterprises to pay more attention to the environmental performance of rotary drilling rigs in the construction process. This not only reduces potential costs caused by environmental pollution issues, such as fines and compensation, but also enhances the social image of the enterprise. The popularization of the full life cycle management concept enables enterprises to view the cost control of rotary drilling rigs from a more macro perspective, comprehensively considering all stages from procurement to scrapping of the equipment, to achieve the optimization control of costs.

        In the future, the cost control of the entire life cycle of rotary drilling rigs will continue to innovate and improve under the promotion of new technologies and new concepts, providing more powerful support for the sustainable development of construction enterprises. Enterprises should keep up with the times, actively introduce new technologies, practice new concepts, continuously optimize cost control strategies, and gain greater advantages in the fierce market competition.