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We present a numerical methodology for the study of convective pore‐fluid, thermal and mass flow in fluid‐saturated porous rock basins. In particular, we investigate the occurrence and distribution pattern of temperature gradient driven convective pore‐fluid flow and hydrocarbon transport in the Australian North West Shelf basin. The related numerical results have demonstrated that: (1) The finite element method combined with the progressive asymptotic approach procedure is a useful tool for dealing with temperature gradient driven pore‐fluid flow and mass transport in fluid‐saturated hydrothermal basins; (2) Convective pore‐fluid flow generally becomes focused in more permeable layers, especially when the layers are thick enough to accommodate the appropriate convective cells; (3) Large dislocation of strata has a significant influence on the distribution patterns of convective pore‐fluid flow, thermal flow and hydrocarbon transport in the North West Shelf basin; (4) As a direct consequence of the formation of convective pore‐fluid cells, the hydrocarbon concentration is highly localized in the range bounded by two major faults in the basin.

We present the finite element simulations of reactive mineral‐carrying fluids mixing and mineralization in pore‐fluid saturated hydrothermal/sedimentary basins. In particular we explore the mixing of reactive sulfide and sulfate fluids and the relevant patterns of mineralization for lead, zinc and iron minerals in the regime of temperature‐gradient‐driven convective flow. Since the mineralization and ore body formation may last quite a long period of time in a hydrothermal basin, it is commonly assumed that, in the geochemistry, the solutions of minerals are in an equilibrium state or near an equilibrium state. Therefore, the mineralization rate of a particular kind of mineral can be expressed as the product of the pore‐fluid velocity and the equilibrium concentration of this particular kind of mineral. Using the present mineralization rate of a mineral, the potential of the modern mineralization theory is illustrated by means of finite element studies related to reactive mineral‐carrying fluids mixing problems in materially homogeneous and inhomogeneous porous rock basins.

The prediction of soil erosion by the action of water has been based largely on the universal soil loss equation and its variations, derived from data collected from agricultural land in the USA. Open pit mining creates waste rock or spoil dumps at the angle of repose of the material (typically 35° to 40°). Even after regrading these slopes, relatively steep slope angles will remain, typically steeper than 6° to 8°. Topsoiling is generally required to facilitate revegetation, but bare topsoil is particularly prone to erosion. Mine slopes are therefore quite unlike the agricultural slopes on which the predictive tools for erosion by water were based. The paper discusses the prediction of erosion from steep mine waste slopes in the light of some erosion data collected from laboratory flume and field studies for open pit coal and gold mining situations in Queensland, Australia. Alternative interpretations of the data are presented, which result in different trends when the data are extrapolated up to angle of repose slopes. The effectiveness of both coarse‐grained riprap on the surface and revegetation in limiting erosion are highlighted.

In 1990 we compiled an annotated bibliography of official state lists of endangered, threatened, and rare species. In gathering information for that bibliography, which appeared in Reference Services Review in Spring 1991, we found numerous unofficial sources of state lists, such as those developed by universities, institutes, and Natural Heritage Programs, which also provide valuable information on statuses of endangered, threatened, and rare species. A comprehensive search for unofficial lists results in this second bibliography.

The purpose of this paper is to give an explanation of the new data available about surface subsidence above the depleted gas reservoir Ravenna Terra. These data confirm the existence after end of exploitation of a reversed subsidence bowl with minimum subsidence above the reservoir, as opposed to conventional subsidence bowls during exploitation which show maximum subsidence in the same location.

The paper analyses these new data about the existence after end of exploitation of a reversed subsidence bowl. The observed behaviour is reproduced successfully with a fully coupled two phase flow code in deforming reservoir rocks which incorporates a constitutive model for partially saturated porous media.

The paper provides successful simulations. These allow affirming with confidence that the explanation for the peculiar behaviour is reservoir flooding and partially saturated rock behaviour.

Further research: other case studies where similar behaviour is expected, e.g. Ekofisk.

The paper includes implications for better management of reservoir exploitation schedules to minimize the observed phenomenon.

This paper explains the peculiar behaviour of subsidence above the depleted gas reservoir Ravenna Terra and confirms the conjecture that constitutive behaviour of partially saturated rocks is the origin of the observed phenomenon.

Natural gas leak from underground pipelines could lead to serious damage and global warming, whose spreading in soil should be systematically investigated. This paper aims to propose a three-dimensional numerical model to analyze the methane–air transportation in soil. The results could help understand the diffusion process of natural gas in soil, which is essential for locating leak source and reducing damage after leak accident.

A numerical model using finite element method is proposed to simulate the methane spreading process in porous media after leaking from an underground pipe. Physical models, including fluids transportation in porous media, water evaporation and heat transfer, are taken into account. The numerical results are compared with experimental data to validate the reliability of the simulation model. The effects of methane leaking direction, non-uniform soil porosity, leaking pressure and convective mass transfer coefficient on ground surface are analyzed.

The methane mole fraction distribution in soil is significantly affected by the leaking direction. Horizontally and vertically non-uniform soil porosity has a stronger effect. Increasing leaking pressure causes increasing methane mole flux and flow rate on the ground surface.

Most existing gas diffusion models in porous media are for one- or two-dimensional simulation, which is not enough for predicting three-dimensional diffusion process after natural gas leak in soil. The heat transfer between gas and soil was also neglected by most researchers, which is very important for predicting the gas-spreading process affected by the soil moisture variation because of water evaporation. In this paper, a three-dimensional numerical model is proposed to further analyze the methane–air transportation in soil using finite element method, with the presence of water evaporation and heat transfer in soil.

This study aims to investigate the compositional characteristics of aromatic hydrocarbons extracted from coals and to describe how the sulfur content influences the properties of coals and whether widely accepted maturity parameters are suitable for medium- to high-sulfur coal.

Four samples of medium- to high-sulfur coal were obtained from Fenxi, Shanxi Province, and studied using gas chromatography and gas chromatography–mass spectrometry (GC-MS).

The GC-MS results showed that there were five series of compounds were identified in the aromatic fractions: naphthalenes, phenanthrenes, oxygen-containing compounds, biphenyls and sulfur-containing compounds. The substituent group was mainly methyl. The content of dibenzothiophenes was high, which was attributed to their high thermodynamic stability. The presence of sulfur reduced the content of oxygen-containing compounds. A depositional environment that facilitated the formation of organic sulfur compounds led to a higher content of naphthalenes.

The development of methods for removing organic sulfur compounds would benefit from a study of their nature, which would be important for improving the use of coal.

Casing damage problems are increasingly prominent in oil fields, most of which were caused by casing external squeezing loads. The traditional calculation method of casing external squeezing loads is not very accurate now, especially in complex formation. The purpose of this paper is to propose a new calculation method to solve the problem of actual casing loads under above conditions.

Based on Lame’s model of elastic mechanics, a new calculation method of casing external squeezing loads is deduced. Comprehensive influence laws of the loads which caused by in-situ stress, internal pressure, formation parameters, cement annulus parameters and casing parameters are analyzed.

The paper provides a new calculation method of casing external squeezing loads, by which the dispersion effect of internal liquid pressure caused by casing wall material is eliminated. The main influence factors of casing external squeezing loads are in-situ stress and formation elastic modulus.

The model and boundary conditions used in the paper is based on elastic mechanics. The accuracy of the calculation results depends on the quality and accuracy of the input formation parameters.

This paper proposes a new method to calculate casing external squeezing loads. And compared with traditional methods, this method is more practical.

To reduce environmental impact caused by excessive use of ordinary Portland cement (OPC) and to mitigate scarcity of base materials such as natural coarse aggregate (NCA), industrial by-products can be carefully used as alternatives to OPC and NCA, in production of concrete. This paper aims to describe the performance of using ground granulated blast furnace slag (GGBS), fly ash (FA) as a complete replacement to OPC and ferrochrome slag (FCS) as replacement to NCA in production of novel FCS based alkali activated slag/fly ash concretes (AASFC) and evaluate their performance at elevated temperatures.

Two control factors with three levels each i.e. FA (0, 25 and 50 per cent by weight) and FCS (0, 50 and 100 per cent by volume) as a GGBS and NCA replacement, respectively, were adopted in AASFC mixtures. Further, AASFC mixture specimens were subjected to different levels of elevated temperature, i.e. 200°C, 400°C, 600°C and 800°C. Compressive strength and residual compressive strength were considered as responses. Three different optimization techniques i.e. gray relational analysis, technique for order preference by similarity to ideal solution and Desirability function approach were used to optimize AASFC mixtures subjected to elevated temperatures.

As FA replacement increases in FCS based AASFC mixtures, workability increases and compressive strength decreases. The introduction of FCS as replacement to NCA in AASFC mixture did not show any significant change in compressive strength under ambient condition. AASFC produced with 75 per cent GGBS, 25 per cent FA and 100 per cent FCS was found to have excellent elevated temperature enduring properties among all other AASFC mixtures studied.

Although several studies are available on using GGBS, FA and FCS in production of OPC-based concretes, present study reports the performance of novel FCS based AASFC mixtures subjected to elevated temperatures. Further, GGBS, FA and FCS used in the present investigation significantly reduces CO₂ emission and environmental degradation associated with OPC production and NCA extraction, respectively.