3D line-support grid flattening for more accurate geostatistical reservoir population with petrophysical properties

Reservoir models are essential if we need to clearly understand the fossil resources and, hence, to make better use of them. Feeding these models with physical properties on the basis of wells data is a key step in their construction. Line-support (LS) grid is the most popular grid in reservoir engineering, it is massively used for reservoir simulations. In the current methods used to populate with properties the LS grid of a reservoir unit, a Cartesian grid of equivalent size (in each direction), obtained by averaging the edge lengths, is first of all completed. The properties calculated in this way are then transferred as they are into the initial LS grid, because there is cell-for-cell correspondence. This leads to distortion of the Cartesian grid, making it fit the shape of the LS grid. This has the effect of altering calculations of correlation distances between well markers in geostatistical population simulations. Consequently, this primarily induces distortions on the simulated bodies. To resolve this problem, in this paper, we propose innovative methods for a “smooth” conversion from the LS grid of the structural space to the Cartesian grid of the geostatistical population space. The basic principle is to calculate the correlation distances between wells on the basis of “quasi-isometric” flattening of the stratigraphic unit LS grid in the population space. This same flattening technique is then used for inverse transfer of the properties from the population space to the structural space.     

Influence of Heating Rate on Ferrite Recrystallization and Austenite Formation in Cold-Rolled Microalloyed Dual-Phase Steels

Compared with other dual-phase (DP) steels, initial microstructures of cold-rolled martensite-ferrite have scarcely been investigated, even though they represent a promising industrial alternative to conventional ferrite-pearlite cold-rolled microstructures. In this study, the influence of the heating rate (over the range of 1 to 10 K/s) on the development of microstructures in a microalloyed DP steel is investigated; this includes the tempering of martensite, precipitation of microalloying elements, recrystallization, and austenite formation. This study points out the influence of the degree of ferrite recrystallization prior to the austenite formation, as well as the importance of the cementite distribution. A low heating rate giving a high degree of recrystallization, leads to the formation of coarse austenite grains that are homogenously distributed in the ferrite matrix. However, a high heating rate leading to a low recrystallization degree, results in a banded-like structure with small austenite grains surrounded by large ferrite grains. A combined approach, involving relevant multiscale microstructural characterization and modeling to rationalize the effect of the coupled processes, highlights the role of the cold-worked initial microstructure, here a martensite-ferrite mixture: recrystallization and austenite formation commence in the former martensite islands before extending in the rest of the material.     

Fusing Loop Detector and Probe Vehicle Data to Estimate Travel Time Statistics on Signalized Urban Networks

Abstract: This article presents a methodology that integrates cumulative plots with probe vehicle data for estimation of travel time statistics (average, quartile) on urban networks. The integration reduces relative deviation among the cumulative plots so that the classical analytical procedure of defining the area between the plots as the total travel time can be applied. For quartile estimation, a slicing technique is proposed. The methodology is validated with real data from Lucerne, Switzerland and it is concluded that the travel time estimates from the proposed methodology are statistically equivalent to the observed values.     

Identification of delay dominant recycle systems

A new identification method for single-input–single-output delay dominant recycle systems is presented in this paper. Identification of recycle systems is similar to that of closed loop systems. However, identification of recycle systems poses certain challenges in that the input-equivalent signal in the closed loop identification is not available for recycle systems. Therefore, special identification routines are required to ensure consistency of recycle and forward models. It is shown that consistent estimates of delay dominant recycle systems can be obtained by treating a delayed output as one of the inputs. Asymptotic variance expressions for the estimates of forward and recycle models are provided. These are then used in designing an optimal excitation signal for recycle systems. The results are illustrated through an industrial example.     

Strong Vortex Pinning in the Low–Temperature Superconducting Phase of (U1−xThx)Be13

We have found a sharp transition at T _c2 = 350 mK in the vortex creep rate of a single crystal of (U _1–x Th _x )Be ₁₃ with T _c = 523 mK (x = 0.0275). For T T _c2 , no creep of vortices is observed in a time scale of 10⁵ s, while for T _c2 < T < T _c , vortices creep at very high rates (30% of decay from a metastable configuration in the first 10⁵ s at T = 400 mK). The sharp transition occurs at the same temperature at which the second jump in the specific heat appears in these samples. Similar low levels of creep rates have been reported by us in the low–T superconducting phase of UPt ₃.¹     

Differential patterns of cell cycle regulatory proteins expression in transgenic models of thyroid tumours

Cell cycle proteins regulate the transitions from G1 to S and G2 to M phases. In higher eukaryotes, their function is controlled by intracellular cascades regulated by extracellular growth factors. We have studied in previously described transgenic mouse models for thyroid proliferative diseases the expression of the key proteins regulating the cell cycle by Western blotting and immunohistochemistry, and have correlated the observations with the known actions of the transgenes on the signal transduction cascades. In the adenosine A2a receptor model, the cyclic AMP pathway, upstream of the Rb family cell division block, is constitutively activated. In the model expressing HPV 16 E7 protein, the Rb-like proteins are inhibited. Cyclin-dependent kinases cdk4, cdk2 and cdc2, and the associated cyclins D, E and A have been studied. Cyclin D3 appears as the major cyclin D subtype expressed in mouse thyroid epithelial cells in normal and transgenic mice. In the adenosine A2aR model, all cell cycle proteins tested were accumulated. In the E7 model, all cell cycle proteins except for D-type cyclins and cdk4 were also accumulated. A similar pattern was observed in thyroids coexpressing both transgenes, suggesting a dominant effect of E7 over the consequences of the cAMP cascade activation. The cyclin-dependent kinase inhibitors p21cip1/waf1 and p27kip1 were not downregulated in these proliferating thyroids which suggest other roles than the inhibition of the cell cycle progression.     

Varying mercury exposure with varying food source in a James Bay Cree community

James Bay Quebec Crees are exposed to methylmercury (MM) through fish consumption. Hair mercury concentrations were measured in women of child-bearing age and men and women 40 years of age and above in a small Cree community of James Bay (with traditionally low exposure to MM) before and after fishing expeditions to inland lakes where fish were contaminated with methylmercury. Median hair mercury concentrations in persons 40 years and above increased from 4.1 mg/kg to 9.9 mg/kg and the highest value from 17.4 to 47.2 mg/kg. A similar increase was seen after a second fishing expedition where the median hair concentration increased from 3.4 mg/kg to 7.2 mg/kg and the highest value from 17.7 to 49.9 mg/kg. Populations with traditionally low exposure to MM can become highly exposed with changes in sources or quantities of fish consumed.     

Bronchoalveolar carcinoma: histopathologic study of evolution in a series of 105 surgically treated patients

BACKGROUND: Liposarcoma arising within a phyllodes tumor is extremely rare. To the best of our knowledge, a malignant phyllodes tumor with liposarcomatous stroma diagnosed by fine needle aspiration (FNA) has not been reported before. CASE: A 39-year-old female had a malignant phyllodes tumor with liposarcomatous stroma diagnosed by FNA cytology. Two subtypes of liposarcomatous stroma, including lipomalike differentiated and myxoid, were found in the aspirates. The cytologic findings were very representative of the histologic features. CONCLUSION: It is very important to recognize the cytologic features of such rare tumors. An accurate diagnosis preoperatively by FNA permits better therapy planning.