Advanced Materials Research Vols. 634-638

Abstract: Flotation characteristics of the fine-disseminated copper-nickel sulfides containing Pt and Pd and thermodynamic properties of high amounts of serpentine gangues by diluted acidic leaching in the ore sample of Yunnan were investigated by bench flotation tests and acidic leaching tests and their combination tests have also been conducted to exploit the harmonious design to extract all the values from the ore sample. Based on the results of bench flotation tests, it has been suggested that traditional flotation with the target of only metallic values in the ore was not available and profitable due to the fact that it was inevitable of the deteriorated dilution of serpentines in the flotation concentration using common various kinds of flocculants or depressants, in which the content of MgO in the concentrate was around 20.0%, while leaching tests by waste acids from producing TiO2 indicated that this may be a promising method to extract MgO andα-Fe2O3 from the ore sample, since it can weaken the disturbance of serpentines significantly and lead a satisfied results of the Cu-Ni sulfide flotation. In this study, a harmonious flow-sheet, which involves leaching by waste acids and traditional flotation process, had been designed with the objective of extracting the metallic values and two non-metallic products, which includesα-Fe2O3 and MgO, from the ore sample. It is worthy noticed that the acidic waste liquids from a TiO2 company in Panzihua was used as leaching agent, which can dissolve 98.81% Mg2+ and 78.43% Fen+ with little Ni2+ and Cu2+. By the comparison of the flotation results and benefits between traditional flotation alone and harmonious design, besides the two more qualified non-metallic products, α-Fe2O3 and MgO, a better concentrate containing a grade of only 2.64% MgO at the grades of 2.58% Cu, 2.97% Ni and 81.02 g/t Pt+Pd with the recoveries of 93.79% Cu, 83.14% Ni and 79.19% Pt+Pd respectively, were harvested from the harmonious design.

Abstract: The paper briefly introduces the phosphate rock resources situation and the processing method of commonly used phosphate rock. Including flotation, scrub off mud, heavy medium dressing, chemical processing method, biological leaching and other methods.

Abstract: When charging in water-filled-hole with emulsion mixed loading truck, if the charging hose can not reach the borehole bottom, there will be a water column in the charge. Emulsion explosive charging in water-filled-hole is simulated under three conditions with different water levels, charging velocity and hole diameter when the hose of the explosive mixed loading truck does not reach the hole bottom. The results show that explosive can not reach the bottom of the blasthole if the water depth exceeds the maximum effective range of the jet flow, which is proportional to charging speed and hole diameter, and there will exist a water column at the bottom of the hole. To prevent that, the distance between the hose outlet and the hole bottom must be shorter than the effective range when charging. Besides, increasing charging velocity also works.

Abstract: In order to know the sealing ability under axial alternating tension load, a 88.9mm×6.45mm P110 premium tubing connection is established with multiple linear elastic plastic finite element model, stress and contact pressure on sealing surface and torque shoulder are analyzed under axial alternating tension load and 80 MPa inner pressure. The results show that tubing connection slide by the axial tension, while the maximum contact pressure on seal surface reduced. With the increasing of alternating cycle, the maximum equivalent stress on seal surface increased and the maximum contact pressure on seal surface decreased. And, under limited loads, contact pressure on torque shoulder is affected little caused by alternating load.

Abstract: The strength safety of perforated string is the premise of safety production of oil well test, detonation parameters of perforating charge is an important factor that affects strength safety of perforated string. On the basis of correctly calculating the detonation parameters such as detonation temperature, detonation heat, detonation volume, detonation pressure and detonation velocity, then adopting the related thermodynamic theory and analyzing the surge pressure of perforated interval, "pocket"of down hole and the packer, thus get the impulsive load of perforation moment and then according to Buckling theory of string to analyze the strength safety of perforated interval tubing string. Considering the fitting sex between the analytic method of the strength safety of perforated interval tubing string and the practical situation of real well cases is very good, and the result of analysis can reflect the state of strength safety of perforated interval tubing string at the moment of detonation, therefore this method can provide primary reference analysis data for the design of strength safety of perforated interval tubing string.

Abstract: By measuring the change of confining pressure penetration on sandstone samples of a gas reservoir in Daqing Oil Field, it has been proven that stress sensitivity existed in this gas reservoirs. The measuring results also show that the stress sensitivity levels of mafic is from weak to medium weak due to the better glutinosity and the greater rock hardness. However, some sandstone samples generally do not have stress sensitivity. The impact of stress sensitivity should be thoroughly considered during the development of natural gas, because the existence of cracks which often result in stronger stress sensitivity.

Abstract: In deep wells and ultra-deep wells the complex geological conditions often result in serious casing wear. In order to be able to accurately measure the wear efficiency and friction coefficient required in the process of the prediction of casing wear, a ring-block drill pipe and casing wear tester is specifically designed and produced, the scheme of tester is proposed, and the design of structure, driving device, and the detecting system of the friction and contact forces of tester is completed. Adopting the ring block drill pipe casing wear tester and simulating down hole conditions P110 casing wear experiments are finished. The results show that the ring block drill pipe casing wear tester meets the requirement of down hole casing wear experiment. P110 casing wear efficiency decreased with the increasing of wear time. The friction coefficient between the P110 casing and the drill pipe sample is about 0.25.

Abstract: In order to research the effects of the concentration of foaming agent and gas-liquid ratio on the steady seepage pressure of the foam, surfactants of HY-3 and HABS are used as foaming agents in this paper. And compared with the steady seepage pressure of the process of injecting CO2 individually and injecting CO2 accompany with dripping water, the results shows that these two kinds of foaming agents both can solve the problem of injecting gas breakthrough and injecting water difficultly, and the effect of HY-3 is better than that of HABS. By the evaluation experiment of the effect of the foam system which was applied in the ultra low permeability reservoirs with crack, it can be seen that these two kinds of foaming agents both can play the role of adjusting gas injection profile. The plugging ability and shunting effect of HY-3 is superior to that of HABS.

Abstract: A mechanical model of casing, formation and cement is established under the action of the in-situ stress in the cementing section. According to the continuous displacement and radial stress conditions, the calculation formulas of loads applied to casing and cement are developed. The influences of geometrical and physical parameters of cement on loads and stresses of the casing and cement are analyzed. The result shows that the increase of Young’s modulus of cement results in that the casing load increases firstly, and then decreases. The bigger Young’s modulus of cement, the more load of cement. Along with the increase of Poisson's ratio of cement, cement and casing load become bigger. Cement load is greater than the casing one, so it can avoid damaging casing.

Abstract: Worn casing often appears in deep and ultra deep well which effected by many factors in drilling process, such as casing grades, drilling fluid density and contact forces, and so on. Using polysulfide water-based drilling fluid, simulating the actual bit pressure, rotary speed and other influencing factors, the wear experiments of TP140,VM140,P110 and N80 casing which often are adopted in the oilfield are completed, and the wear efficiency and friction coefficient which are adopted to predict down hole casing wear are obtained. The experimental results show that the higher casing steel grade, the greater the hardness, the better wear performance. The experiments can help deepen the understanding of the mechanism of casing wear. Adopting the results which are obtained in research the prediction accuracy of down hole casing wear can be improved.