scholarly journals Research on the Construction of a Petrophysical Model of a Heterogeneous Reservoir in the Hydrate Test Area in the Shenhu Area of the South China Sea (SCS)

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Xing Lei ◽  
Liu Xueqin ◽  
Liu Huaishan ◽  
Qin Zhiliang ◽  
Ma Benjun
Keyword(s):  
Influence Factors ◽  
Elastic Model ◽  
Shenhu Area ◽  
Pore Filling ◽  
Correction Model ◽  
Three Phase ◽  
Petrophysical Model ◽  
Occurrence Characteristics ◽  
Cementation Factor ◽  
Hydrate Reservoirs

The occurrence characteristics of hydrates in the Shenhu area reflect a typical inhomogeneity in terms of spatial distribution. It is difficult to accurately describe the petrophysical properties of a reservoir using a petrophysical model considering a single cementation factor parameter. According to the analysis of a mathematical model and the estimation results of V p and V s , the unique structure of foraminiferal sediment particles provides opportunities for forming a diversified hydrate occurrence in the foraminiferal area. In areas where hydrates are thin and interbedded, hydrate reservoirs are generally three-phase media, with obvious thermoelastic properties. Therefore, the parameters of the three characteristic models of the pore-filling model, particle cementation model, and thermodynamic elastic model are all included in the correction model. The weights of the influence factors are then changed to realize an accurate description of the petrophysical characteristics of the correction model in different drilling areas and at different formation depths, reducing the limitations of using a single petrophysical model to describe the petrophysical characteristics of heterogeneous regions under the influence of multiple factors.

scholarly journals Three-Phase Text Error Correction Model for Korean SMS Messages

2009 ◽  
Vol E92-D (5) ◽  
pp. 1213-1217 ◽  
Author(s):  
Jeunghyun BYUN ◽  
So-Young PARK ◽  
Seung-Wook LEE ◽  
Hae-Chang RIM
Keyword(s):  
Error Correction ◽  
Error Correction Model ◽  
Correction Model ◽  
Three Phase

The Carbonic Acid Reaction of Phosphogypsum Decomposition Slag in the Three-Phase Fluidized Ded

2012 ◽  
Vol 550-553 ◽  
pp. 2921-2926 ◽  
Author(s):  
Yu Hang Chen ◽  
Li Ping Ma ◽  
Ren Yang ◽  
Hang Zhang ◽  
Long Gui Xie ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Gas Flow ◽  
Carbonic Acid ◽  
Influence Factors ◽  
Fluidized Bed Reactor ◽  
Inhibitory Effect ◽  
Co2 Gas ◽  
Solid Ratio ◽  
Three Phase ◽  
Acid Reaction

Through the study on influence factors of the carbonic acid reaction of phosphogypsum decomposition slag in the three-phase fluidized bed, the effect of different factors on the transformation of CaS in the phosphogypsum decomposition slag was discussed. Experiments show that Increasing CO2 gas flow and extending reaction time have benefit for the transformation of CaS. The conversion rate of CaS was increased firstly and then tended to flatten with the increase of the liquid-solid ratio. The rise of reaction temperature has a weak inhibitory effect for the transformation of CaS. Comparing with tank reactor, three-phase fluidized bed reactor is more advantageous to the carbonic acid reaction of phosphogypsum decomposition slag.

scholarly journals A Study on the Electrical Characteristics of Fractured Gas Hydrate Reservoirs Based on Digital Rock Technology

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Hu Yang ◽  
Xiaojun Xue ◽  
Xianghui Chen ◽  
Junyu Xie ◽  
Qinglong Zheng
Keyword(s):  
Gas Hydrate ◽  
Turning Point ◽  
Water Saturation ◽  
Electrical Anisotropy ◽  
Saturation Curve ◽  
Electrical Characteristics ◽  
Pore Filling ◽  
Digital Rock ◽  
Hydrate Saturation ◽  
Hydrate Reservoirs

Abstract The electrical characteristics of fractured gas hydrate reservoirs were investigated through the diffusion-limited aggregation model, digital rock technology, and the finite element method. The results show that the fracture and gas hydrate have a significant effect on the electrical characteristics of rock partially saturated with gas hydrate, where the matrix pore and fracture mixed gas hydrate form a dual-porosity system. Due to the fracture and gas hydrate effect, the electrical characteristics of fractured gas hydrate reservoirs cannot be described well by traditional Archie equations. The resistivity index vs. water saturation curve of fractured gas hydrate reservoirs shows a nonlinear relationship for different gas hydrate pore habits (pore-filling, cementing, and grain-coating types), and this curve consists of two parts with different gas hydrate saturation exponents for pore-filling and cementing gas hydrate and presents a curve without a fixed water saturation exponent for grain-coating gas hydrate. Fractured gas hydrate reservoirs with different fracture apertures, different gas hydrate pore habits, and saturation features will lead to macroscopic electrical anisotropy. The results of theoretical analysis and numerical simulation show that the electrical anisotropy coefficient of fractured gas hydrate reservoirs is a function of gas hydrate saturation. The function curve consists of three segments with the turning point for pore-filling and cementing gas hydrate, and this curve can be divided into two parts through the turning point. The findings of this study can help for a better understanding of the electrical characteristics of fractured gas hydrate reservoirs, which have great significance for the exploration and development of gas hydrate resources.

A minimisation algorithm with application to optimal design of reinforcements in textiles and garments

2007 ◽  
Vol 19 (3/4) ◽  
pp. 159-166
Author(s):  
Željko Šomodi ◽  
Anica Hursa ◽  
Dubravko Rogale
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Objective Function ◽  
Influence Factors ◽  
Element Model ◽  
Geometrical Parameters ◽  
Elastic Model ◽  
Element Analysis ◽  
Elliptic Paraboloid ◽  
Content Type

PurposeThis paper aims to develop an efficient two‐variable minimisation algorithm and to apply it in engineering optimisation of buttonhole reinforcements.Design/methodology/approachAn iterative extreme search is based on quadratic approximation of objective function, locating approximate solution at the minimum of corresponding elliptic paraboloid. Stress analysis is performed using plane stress finite element model. Optimal selection of geometrical parameters of buttonhole‐type reinforcement is done in terms of balance between maximum stress and material consumption.FindingsAdopted minimisation algorithm is assessed in a selected test example and proven to perform well in comparison with methods available in literature. In the selected case two local minima have been found within the predefined optimisation domain, with slight difference in objective function values.Research limitations/implicationsResearch is limited to homogeneous isotropic elastic model and a single representative load case. Objective function is restricted to two influence factors and predefined optimisation domain.Practical implicationsThe method can be useful for engineers/practitioners in the branch of clothing technology as a tool for computational estimate of optimal design of structural reinforcements.Originality/valueThe main quality of the paper is in software fusion of finite element analysis and advanced optimisation algorithm. The proposed theoretical‐numerical model is discussed in terms of applicability in parameter setting on buttonholer in garment production.

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