The influence of flushing fluids rheological properties on rock breaking efficiency when drilling wells by pellet impact drilling method

Introduction. Pellet impact drilling method which is basically the destruction of rocks by blows of pellets, has been studied by many researchers. Despite this, the rheological properties of the drilling fluid used in pellet impact drilling have not been investigated yet. All bench and field tests were carried out using service water. The use of a drilling fluid with a higher viscosity than water has the potential to expand the field of application of pellet impact drilling. Therefore, it becomes urgent to study the effectiveness of destruction of rocks when using flushing fluids with different rheological parameters. Objective of this research is to investigate the efficiency of rock destruction in the process of drilling wells using the pellet impact drilling method at various rheological parameters of the drilling fluid. Methods of research. A scaled laboratory bench was used in the research. The bench was a closed system of circulation of the drilling fluid (drilling mud). The solution was prepared separately on a high-speed mixer. The main part of the bench was a scaled pellet drill bit located in a simulated well. After the experiment, the destructed rock volume and the rheological parameters of the flushing fluid were measured. A series of experiments was carried out with a gradual increase in the viscosity of the flushing fluid. A biopolymer (xanthan gum) in various concentrations was used to thicken the flushing fluid. Drilling fluid rheological parameters were measured using an eight-speed rotary viscometer and a Marsh funnel. Results. For the first time, a relationship has been established between the efficiency of rock destruction during pellet impact drilling and the rheological parameters of the drilling fluid used. It was found that with an increase in the concentration of biopolymer and an increase in viscosity, at first, there was a significant increase in the volume of drilled rock per unit time, and with a further increase in concentration, a gradual decrease occurs. Conclusions. The results obtained expand the field of application of pellet impact drilling. The reliability of predicting the drilling speed is improved depending on changes in the properties of the drilling fluid. Based on the results, recommendations were made for the selection of the optimal parameters of the drilling fluid, depending on the drilling conditions.

Energy Auditing for Efficient Planning and Implementation in Commercial and Residential Buildings

The ideology of ensuring energy-efficient design and construction of buildings by providing minimum requirements is the core objective of this work. Energy audit was conducted to improve the design of the building with incremental requirements to further enhance the energy efficiency. The Energy Conservation Building Code (ECBC) has been modified extensively over the years, starting from its initial deployment in the year 2011 to its latest modifications in the year 2019. The energy conservation standards in ECBC apply to building envelope, heating ventilation, air conditioning, lighting, service water heating, and electric power distribution. It should also be ensured that all-electric systems, transformers, energy-efficient motors, and diesel generators must meet the regulated set of mandatory requirements. From among the various software types that have been approved for ECBC design and application, this study has employed Energy Plus software to simulate the design based on the given input and the selected location. The location that has been chosen for this study was Bhubaneshwar, India. All necessary details ranging from latitude, longitude, weather, time zone, elevation, building area, lighting, heating, cooling, and much more have been covered in the simulation. Utilizing ECBC regulated standards for an energy-efficient building design has resulted in an increase in the energy savings by 27.4%, and thus, the building qualifies to be regarded as an ECBC compliant building.

Urbanisation and Infrastructural Development in Nagaland: A Case Study of Kohima and Mokokchung District

Urbanisation is now becoming a global phenomenon, high rate of population growth; declining opportunities in rural areas and shift from stagnant and low paying agriculture sector to more paying urban occupations, largely contribute to urbanization process. This paper studies the level of physical and social infrastructural progress in Kohima and Mokokchung districts using seven indicators such as education institution, health, banking, postal service, water supply, surface road cover and electricity. Research survey was conducted in Kohima and Mokokchung in 2017-18. The sample wards were selected using random sampling methods. The data’s collected were than analyzed using Principal Components Analysis Model. The findings shows that 50% of urban areas are in developed and 37.5% in moderately developed and 12% in less developed with regard to surface road, medical facilities, education, postal service, banking and water supply. The study highlights that urbanisation has positive impact on infrastructure development in sample districts. The study also found the urban areas of Kohima are in leading position than Mokokchung with regard to social and physical infrastructure. The paper concludes by suggesting suitable policies for developing and less developed areas. Keywords: Urbanisation, Social and Physical Infrastructure

DCPD and strain gauge based calibration procedure for evaluation of low temperature creep behavior

Creep cracking is one of the key forms of structural material SCC damage with respect to nuclear power. Accurately obtaining the amount of creep deformation is also an important basis for estimating the service life of structural parts. However, because the primary circuit of nuclear power occurs in a high-temperature and high-pressure service water environment, it is not possible to use a conventional extensometer to obtain accurate creep of gauge length under these conditions. Considering that DCPD is an important method for monitoring crack propagation in a high-temperature water environment, by taking the austenite 304 stainless steel commonly used for nuclear power as a research object, a calibration method based on a combination of DC potential drop (DCPD) and strain testing to obtain the creep deformation of the specimen was established. By comparing theoretical research with experimental results, it can be concluded that the calculation results of the model are close to the experimental results and consistent with the theory, thus proving the feasibility of using DCPD technology to obtain the creep deformation amount.

Sludge water stabilization treatment

Technologically contaminated water, formed during processing of coal slurries, finds its application in modern technological cycles of coal enrichment. Limitation of use of untreated recycled water of coal concentration plants is caused by a high degree of its mineralization by various salts, presence of insoluble solid particles and presence of flotation reagents, coagulants and flocculants. Part of technical water purified from mineral and organic contaminants can be used in heating systems and heat exchange equipment of industrial enterprises, including the coal industry. For this purpose, it is necessary to reduce the scale-forming ability of service water (to reduce the content of soluble calcium and magnesium salts in water). One of the most effective and advanced methods is the stabilization treatment of water with an electric field. In addition, this method is environmentally safe, low-cost and simple. The article gives the foundation of the method of stabilization treatment of recycled water of concentrating plants by an electric field, a description of the methodology of the laboratory experiment for scaling reduction, and the analysis of the results.

Bearing Capacity Analysis of Spun Pile Foundation in Gas Engine for Electrical Power Plant Project of Selayar

Gas Engine for Electrical Power Plant Project of Selayar is a power plant which will be built in Selayar Regency. This plant uses gas and biodiesel as a fuel. The facilities needed in the power plant construction includes a Gas Engine, Service Water Tank and Biosolar Tank. This study aims to obtain the allowable bearing capacity of the prestressed spun pile foundation for the three buildings based on soil investigation data of SPT (Standard Penetration Test) at BH-1 (gas engine), BH-2 (service water tank) and BH-3 (biosolar tank). The Meyerhof formula is used for the calculation of ultimate bearing capacity analysis on prestressed spun piles with various diameters for each depth. Calculation of the allowable bearing capacity (Qa) of the foundation at a depth of 19 meters, using a spun pile with a diameter of 300 cm, obtained a Qa value of 94.17 tons at BH-1, 94.20 tons at BH-2, and 74.65 tons at BH-3. Using a spun pile with a diameter of 400 cm, the Qa values were 116.71 tons on BH-1, 117.64 tons on BH-2, and 91.92 tons on BH-3. Using a spun pile with a diameter of 500 cm, the Qa values were 168.67 tons on BH-1, 172.09 tons on BH-2, and 131.49 tons on BH-3. Meanwhile, the values of Qa obtained were 229.85 tons on BH-1, 236.66 tons on BH-2, and 177.79 tons on BH-3 with the use of a spun pile with a diameter of 600 cm.