Applied Mechanics and Materials Vol. 700

Abstract: Two conversion methods were used to correct regional errors of geochemical data. The results showed that both normalization method and conversion method of standard normal distribution could correct regional errors of geochemical data well. Normalization method had simple correction course but lower accuracy. Conversion method of standard normal distribution was more complex than normalization method, but correction effect was better. There was no obvious regional error in geochemical isograds with data which had been converted.

Abstract: The best is to read these instructions and follow the outline of this text. To improve the injection steam enthalpy is the key technology in ultra-heavy oil thermal development. The wellbore heat insulation technology is needed to keep the process of steam injection hot enthalpy, to reduce heat loss utmost, to prevent the damage of the casings and cement mantle in high-temperature steam. The conventional cased-hole completions require the borehole thermally insulating insulation technology in thermal recovery, and generally adopt insulated tubing steam injection, ordinary tubing transfer pumping, which will cause frequent operations and enlarge the accidental risks caused by a number of down hole tools which are tripped in wellbore. Insulation casing well completion technology can effectively solve the wellbore insulation problems, and improve the casing and cement mantle security, increase the production rate. The field applications in Henan Oilfield have obtained excellent results; two wells were operated with completion technique by heat insulated casings. Compared with the same types of wells in the pilot test ultra-heavy oil block, the production is about twice as much as those of other wells, and the economic effect is obvious.

Abstract: According to the Darcy - Stokes equations of fractured-vuggy porous medium, using COMSOL Multiphysics software, we calculated several typical conceptual model pressure field distribution, analyzed the influence of fractured-vuggy porous medium internal vug and fractured geometric configuration on the pressure field in the model.

Abstract: Based on the oil slick pervasion theory and hydrodynamic model, a risk prediction model was established for the oil-spill simulation in open-ocean coastal port. The model was calibrated with the typical hydrological and meteorological data of the study area, to predict the environmental impact on Yantai west harbor dock. The results indicate that on account of the wind from south-south-west and south-west, the spilled oil will reach the shore in 2 hours and 4 hours respectively, the spreading range can be controlled in Zhifu Bay dock basin. But under the condition of westerly winds, oil slick will drift out of the dock basin in 2 hours, affecting two ecological fragile areas in 6 hours and 12 hours successively, which means a significant risk for open-ocean area.

Abstract: The nonlinear spherical seepage flow model has been established for the composite reservoir model. The nonlinear spherical seepage flow model considers the well produce at a constant rate, and the quadratic gradient term under three outer boundary conditions (closed, constant pressure and infinite). Firstly, through variable substitutions, the seepage flow equation is linearized; then the model is transformed into the boundary value problem of an ordinary differential equation by employing the Laplace transform method. It has been confirmed that the Laplace space analytic solutions of such boundary value problems has a formula under different external boundaries, using the Similar Constructive Method(it is a simple and effective new idea for solving this class seepage flow model, complicated calculus calculation is avoided). The prospect of this new method is promising for understanding and studying the inherent laws of fluids flow.

Abstract: In order to decide the formula of ASP system to be used in Henan oilfield, the weak base ternary composite system compounded with petroleum sulfonate(Ss), polymer and weak base; the alkali ASP system compounded with alkylbenzene sulfonates(Sy), polymer and alkali were studied, and the oil-water interface behaviour of Henan oilfield with weak base ASP system compounded with surfactant SHSA-HN6 and ZL-Ⅱ polymer was evaluated. The results showed that the interfacial tension reduction effect of Weak base ternary system is better than that of Alkali ternary system; the interfacial tension between oil and water can be reduced significantly by the weak base ternary system compounded with surfactant (Ss) and polymer (ZL-Ⅱand KYPAM). After adding 1.2% Na₂CO₃ to the mixture of surfactant (SHSA-HN6) and polymer, the interfacial tension of Henan oil-water was reduced to the ultra-low level(>10^-3mN/m).

Abstract: Through the method of physical simulation, the seepage flow characteristics of polymer solution with different mass concentrations were studied, which polymer is from Daqing Refining & Chemical Company with molecular weights of 9.7 million, 19 million, 25 million. In the condition of same slug combinations, the displacement effect of polymer solution with different mass concentrations and molecular weights were studied. The results show that the polymer solution (molecular weight is 1.9×10⁷, concentration is 1500mg/L) has a good match with the artificial core of this tract; and with the increase of polymer molecular weight, oil recovery of chemical flooding and total recovery raise up; in the condition of the same molecular weight, the oil recovery of chemical flooding will increase with the polymer mass concentration.

Abstract: Fluid seepage needs to overcome threshold pressure gradient in low permeability reservoir and heavy oil reservoir. A conclusion about the research progress of threshold pressure gradient was made by summarizing the literatures, which includes: the existence and experimental study of threshold pressure gradient, research of seepage theory considering threshold pressure gradient and applications. These can supply reference for the researching and engineering staffs engaged in related work.

Abstract: Fluidized beds are widely used in a variety of industrial processes. The air distributor being an integral part of the fluidized bed, the air flow characteristic through it is of great importance as far as the design and working of it is concerned. Inappropriate design will lead to an incomplete fluidization and improper mixing of the air and bed particles. The current study was carried out to investigate the flow characteristics and predict non-uniformity in flow through the annular distributor of a Swirling Fluidized Bed and its variation with various aspects of the distributor like blade overlap angle and blade inclination. In this study, the commercial CFD package FLUENT 6.3 was used for analysis. The velocity and pressure profiles for various blade designs were investigated at the distributor outlet based on several operating variables including air inlet velocities, blade overlap angles (9^o, 12^o, 15^o, and 18^o), blade inclinations (10^o and 15^o), along with variations in the opening between the distributor blades. The most significant finding of this work is that the fluid tends to flow through a path with least resistance. The flow path with the largest cross section area and shortest path length has been identified and explains the velocity profile at blade exit.

Abstract: Erosion-corrosion behavior in downhole tubulars and oilfield ground gathering transferring system is interesting in optimum design. This work is addressed to investigate erosion-corrosion behavior of hydraulic perforating equipment during fracturing. The typical fracturing fluid of 0.2% hydroxypropyl guar gum solution mixed with quartz grain was selected. The relationship between erosion-corrosion rate and flow displacement, the effect of the flow impact angle on erosion-corrosion rate is performed on a jet impingement experimental apparatus. In the experiment situation, the erosion-corrosion rate reaches highest at the impact angle of 45°. The erosion-corrosion rate increased exponentially with the increase of flow displacement. The surface morphology of specimen suffer from erosion-corrosion is analyzed by scanning electron microscopy (SEM) to characterize the erosion-corrosion damage mechanisms.