Mechanical cleaning of calcite scaling with rotating control head preventer in a geothermal well

This paper presents the mechanical methods used for calcite scale cleaning of wells in the Kizildere geothermal field in Western Turkey. A geothermal power plant with a capacity of 20.4 MWe has been operating in the field since 1984. During production well diameter reduces because of calcite scaling which has been a continuous problem since the beginning of energy production from the field. The calcite scaling decreases power generation from 15 MWe to 10-12 MWe, increase capital cost, pumping costs and cleaning and maintenance costs. Scaling in the wells has been mechanically reamed periodically since 1984 to increases the production from the wells. Since mechanical cleaning with mud or water circulation causes reservoir contamination, KD 7 well was reamed while the well was flowing using Rotating Control Head Preventer (RCHP) for the first time in 1990. This method has been used successfully since 1991 at all wells. In this study the results of the mechanical cleaning with mud or water, and mechanical cleaning with Rotating Control Head Preventer methods were evaluated

An indolent course of multiple myeloma mimicking a solitary thyroid cartilage plasmacytoma

Multiple myeloma, solitary plasmacytoma, and extramedullary plasmacytoma constitute a continuum of a disease spectrum, which is called plasma cell neoplasms. These three entities can not be differentiated from each other on a histological basis and, for this reason, clinical evaluation is important in their differential diagnoses. Differential diagnosis guides the proper planning of treatment and helps in estimation of survival. Multiple myeloma located within the larynx is very rare. Because of its rarity, any established diagnostic and treatment criteria do not exist. In this report, a case of laryngeal multiple myeloma is presented for its extraordinary presentation and also for educational purposes

A new approach to rock brittleness and its usability at prediction of drillability

Rock brittleness is one of the most important issues in rock drilling and cutting. The relations between drillability and brittleness will assist engineers in excavation works. The demand for representative rock parameters related to planning of underground excavations is increasing, as these parameters constitute fundamental input for obtaining the most reliable cost and time estimates. In rock cutting mechanics, the effects of the rock and brittleness on the efficiency of drilling and excavation are examined by many researchers. In this study, 41 different rock types were tested in laboratory to investigate the relations between the drilling rate index and different brittleness values. Firstly, the relations defined in literature are tested. Strength tests are made according to International Society for Rock Mechanics standards. In addition Norwegian University of Science and Technology standards are used to determine drilling rate index. Then, a new brittleness index is proposed which is the arithmetic average of uniaxial compressive strength and tensile strength. Considering the regression analysis carried out, it was seen that the proposed formula showed good correlation for these samples handled in this study. As a result of this study, a high correlation is obtained between the proposed index and drilling rate index values (R:0.84). The results are found to be at least reliable as well as other brittleness equations given in literature. © 2016 Elsevier Ltd.2007KBFEN53This study was supported by Scientific Research Coordinator of Dokuz Eylul University under the project number of 2007KBFEN53. The authors gratefully acknowledge reviewers for contribution to the study and also special thanks to Prof. Dr. Bjorn Nilsen (NTNU, Norway), Filip Dahl (SINTEF, Norway) and Prof. Dr. Amund Bruland (NTNU, Norway) for developing drilling rate index test procedures

A case study for an open pit coal mine induced slope failure affecting an industrial plant in Turkey

Can Lignite Establishment belonging to T.K.I (Turkish Coal Enterprises) has been operating an open pit over two decades. Three years ago, the boundary of the open pit came close to one of the biggest Ceramic Factory in Turkey namely Canakkale Ceramic Factories. Since the be,beginning of the coal extraction in the area, small scale slope Failures including several benches have been observed. But in 17 August 1999, due to catastrophic earthquake centred in Golcuk, huge amount of material started sliding. Bigger size of landslide provoked by both the earthquake and activities in open pit mining showed itself with tension cracks in backyard of the Ceramic Factory. This paper introduces the measurement done to define the slip surface then what precautions have been taken to stop slope Failure