Although numerous studies have investigated how shocks and vibrations contribute to bottomhole assembly (BHA) failures during hole-making, very few have explicitly focused on shock and vibrational behaviors during drillpipe connections. This study adopts a data-driven approach to explore various connection practices and their associated shocks and vibrations, aiming to propose optimum "connection recipes" that minimize negative drillstring impacts during connections. This study utilized data from surface sensors as well as downhole accelerometers and gyroscopes installed both at a downhole sub and the bit. In total, 520 connections from 5 lateral sections were studied. Several quality checks and corrections were performed to ensure synchronization between surface and downhole data. The analyses focused on two connection phases specifically: going off-bottom and going back to bottom. The presence of stick-slip events and high magnitudes of both maximum and root mean squared (RMS) radial accelerations were examined together with the associated surface drilling parameters. Various visualization approaches were performed to help demonstrate the vibration and shock behaviors resulting from different going off-bottom and going back to bottom practices. The analyses showed that restarting surface rotational speed at low values (≤ 40 RPM) risks inducing stick-slip events when going back to bottom. When the surface RPM was increased sufficiently, a notable reduction in RMS radial acceleration was observed. Maximum radial acceleration magnitude was highest before WOB application, which could be mitigated by immediate WOB re-application. Appreciable variation in the maximum radial acceleration was apparent when restarting at low (≤ 15 klbf) WOB values. When going off-bottom, drilling off should be accompanied by a reduction in the surface rotational speed to avoid a jump in the maximum radial acceleration values. This work provides suggestions on how to execute better connections. Since the impacts of shocks and vibrations during connections have previously been largely overlooked, this study fills a knowledge gap to help establish better practices and automation routines to improve the lifespan of the bit and downhole tools.
In this study, evolution of microstructural, hardness value, and dimensional crosshead valve that has been welded with Ni-Cr-B-Si-C alloys deposit are investigated. Ni-Cr-B-Si-C alloys has deposited to replace nickel alloys on component that have wear. The process that used is GTAW welding process with variation of amperes and with or without using water backing technique. Result from this study, on weld metal microstructure with variation of heat input and water backing method made same structure like original materials. On base metal microstructure, resulting same structrue as original material that consist of ferrite and pearlite. However, on HAZ which used 140 A on welding current and water backing method produced martensite structure. The greater heat input make a greater hardness value on weld metal and water backing can keep the original hardness from material. In addition, heat input and water backing that used in this processs not cause a deformation on crosshead components result from dimensional test which still suitable with original component specification.
Pack carburizing is one method of adding carbon into the steel surface. This method is done to improve the mechanical properties of steel so as to reduce the risk of material failure due to static and dynamic load. It has been done in this research about pack carburizing with mixed bintaro charcoal media with coconut shell on ST 41 steel. Carburizing method is done by heating steel which is given a mixture of charcoal at 900 celsius temperature with variation of holding time (1h, 1.5h, 2h) And variation of the charcoal mix ratio with BaCO3 (90: 10, 85: 15, 80: 20). Conducted testing of microstructure, jominy, and the composition so it is known that the mixture of bintaro charcoal and coconut shell quite effectively used as a media pack carburizing. It can be seen that the hardness value of carbon steel has increased with the highest value of 65 HRC, metallographic test results showed good carburizing coating with the best thickness value of 30.9 µm, in jominy testing showed the low hardness carbon steel ability increased with the highest distance from the specimen quench-ends about ¾ inch and on the compositional test results showed an increase in carbon content in steel more than 200%.
Guru Madrasah masih memiliki kecenderungan melakukan pembelian barang dalam memenuhi kebutuhan dasarnya tanpa memperhatikan prinsip finansial yang ada. Penelitian ini bertujuan untuk mengetahui persepsi guru terhadap model pengelolaan keuangan dan perilaku konsumtif.Metode yang digunakan dalam penelitian ini adalah kualitatif deskriptif. Desain penelitian ini menggambarkan fenomena objek penelitian, mengumpulkan informasi tentang fenomena objek penelitian, dan melaporkannya secara naratif tentang temuan yang didapatkan.Lokasi penelitian ini adalah Madrasah Aliyah Al Fatah yang terletak di Desa Temboro, Kecamatan Karas, Kabupaten Magetan.Jenis sumber data menggunakan data primer dan data sekunder. Adapun sumber data primer penelitian ini adalahguru sertifikasi. Sedangkan data sekunder meliputi foto-foto selama kegiatan penelitian berlangsung. Teknik pengumpulan data yang digunakan adalah teknik wawancara, observasi, dan dokumentasi.Hasil penelitian menunjukkan bahwa guru sertifikasi memiliki kesadaran mengenai pentingnya memiliki pengetahuan dan keterampilan dalam mengelola keuangan, meliputi perencanaan seperti mengelola dana tabungan, mengelola investasi, dan mengikuti program asuransi yang melibatkan jasa perbankan sehingga dapat menghindari perilaku konsumtif
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