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DOE High-Power Slim-Hole Drilling System
This project used a systems approach to improve slim-hole drilling performance. A high power mud motor, having a double-length power section, and hybrid PDC/TSP drill bit were developed to deliver maximum horsepower to the rock while providing a long life down hole. This high-power slim-hole drilling system drills much faster than conventional slim-hole motor and bit combinations and holds significant potential to reduce slim-hole drilling costs. The oil and gas industries have been faced with downward price pressures since the 1980s. These pressures are not expected to be relieved in the near future. To maintain profitability, companies have had to find ways to reduce the costs of producing oil and gas. Drilling is one of the more costly operations in the production process. One method to reduce costs of drilling is to use smaller more mobile equipment. Slim holes have been drilled in the past using this principle. These wells can save money not only from the use of smaller drilling equipment, but also from reduced tubular costs. Stepping down even one casing size results in significant savings. However, slim holes have not found wide spread use for three reasons. First, until recently, the price of oil has been high so there were no forces to move the industry in this direction. Second, small roller bits and motors were not very reliable and they drilled slowly, removing much of the economic benefit. The third and final reason was the misconception that large holes were needed everywhere to deliver the desired production. Several factors have changed that will encourage the use of slim holes. The industry now favors any method of reducing the costs of producing oil and gas. In addition, the industry now understands that large holes are not always needed. Gas, in particular, can have high production rates in smaller holes. New materials now make it possible to manufacture improved bits and motors that drill for long periods at high rates. All that remains is to gather all the elements together and demonstrate the savings of slim hole drilling
停留精巣の研究 第3報: 停留精巣患者における精巣内複合糖質の組織化学的研究
3~37歳の停留精巣患者23例の停留精巣および対側陰嚢内精巣において, 光顕組織化学的方法にて複合糖質の変化を観察し, さらに正常精巣組織と比較した.停留精巣精細管壁及び間質では, 正常精巣に比べ酸性ムコ多糖(精細管壁:コンドロイチン硫酸A及びC, 間質:コンドロイチン硫酸B)が減少し, 特に精細管壁において顕著であった.なお, 患側精細管上皮においては, 思春期前から思春期以後を通じ, グリコーゲン及びガラクトース含有量の減少が認められたThe complex carbohydrates in the undescended and contralateral scrotal testes of patients with cryptorchidism, were examined by light microscopic histochemical methods, in comparison with those of normal testes. In the undescended testes, histochemical reactions for acidic and neutral complex carbohydrates were apparently weaker than in the normal testes, especially pronounced in the seminiferous tubular walls. In the germinal and supporting cells of the undescended testes, the amount of galactose residues in the complex carbohydrates decreased from the prepubertal to post-pubertal periods. Periodic acid-Schiff reaction also revealed a decrease in the glycogen content in the germinal and supporting cells of the undescended testes from pre-pubertal to post-pubertal periods