Quantitative Model of Optimization on Non-Oil Based Fuel Alternative Energy

Research of “Quantitative Model of Optimization On Non-Oil Based Fuel Alternative Energy” is using goal programing method approach which will generate comprehensive mathematic models to determine policy on alternative energy field beside oil based fuel. The result of the research is sensitivity analytic model and optimization model of nonoil based fuel alternative energy. Developed model is goal programing to optimise alternative energy beside oil based fuel. Model implementation conducted on alternative energy are coal, nature gas and hydro. And the calculation result using Expert Choice Version 9.0 is obtained that coal as alternative energy has relative priority value of 36,8% at overall consistency index 0,04 or 4%. Optimization implemented model conducted at alternative oil based energy plan using calculation of Quantitative System 3.0 program conclude that coal = 9.809274, gas = 0.8409028, hydro = 0. Minimal objective = 18.69225

Th-MOF showing six-fold imide-sealed pockets for middle-size-separation of propane from nature gas

Separation of propane from nature gas is of great importance to industry. However, in light of size-based separation, there still lacks effective method to directly separate propane from nature gas, due to the comparable physical properties for these light alkanes (C1-C4) and the middle size of propane. In this work, we found that a new Th-MOF could be an ideal solution for this issue. The Th-MOF takes UiO-66-type structure, but with the pocket sealed by six-fold imide groups; this not only precisely reduces the size of pocket to exactly match propane, but also enhances the host-guest interactions through multiple supramolecular interactions. As a result, highly selective adsorption of propane over methane, ethane, and butane was observed, implying unique middle-size separation. The actual separation was confirmed by breakthrough experiments, and it is found that both relatively smaller molecules (methane and ethane) and relatively bigger molecules (butane) break through the Th-MOF column within 10 min/g, whereas propane with middle size can maintain very long retention time up to 80 min/g, strongly suggesting middle-size separation and its superior application in direct separation of propane from nature gas. The separation mechanism, as unveiled by both theoretical calculation and comparative experiments, is due to the six-fold imide-sealed pockets that could effectively distinguish propane from other light alkanes through both size effect and host-guest interactions.

Burst Failure Analysis of a HFW Pipe for Nature Gas Pipeline

The burst failure of a high frequency welded (HFW) pipe used for nature gas pipeline in an oilfield was analyzed systematically by macro analysis, physical and chemical property test, scanning electron microscope (SEM), etc., and the limit internal pressure of the pipeline under operation condition was predicted based on finite element method (FEM). The results showed that the chemical composition and mechanical properties of the pipe meet the requirements of relevant standards. The failure results showed that the dent damage of the straight pipe section was at 12 o'clock. In the service of the pipeline, the stress in the dent area exceeds the yield strength, which leads to the plastic deformation of the pipeline, resulting in necking and thinning, and the reduction of wall thickness further leads to the decrease of ultimate internal pressure, until the ultimate bearing capacity of the dent area is less than the internal pressure of pipeline operation, resulting in burst. It is suggested to strengthen the supervision of pipeline construction to avoid the pipeline dent damage. Meanwhile, the operation monitoring of the pipeline with dent damage should be strengthened, and timely repair or depressurization operation should be carried out if necessary.

A Prediction Model of Wellbore Temperature Based on Hydration Kinetics During Well Cementing in Nature Gas Hydrates

Stability of nature gas hydrates (NGH) is greatly impacted by temperature. Because intense heat is released from cement hydration during well cementing, limiting the temperature rise of cement is critical for safe cementing of NGH well. The total heat release by cement slurry has a strong correlation with the mechanical properties of cement slurry. Consequently, reducing the heat of hydration of cement means typically results in lower strength of the cement stone. Traditional evaluation methods do not fully consider the complex interaction between cement hydration reaction and heat transfer in the wellbore, therefore, it is difficult to determine whether the cement slurry formula selected is suitable for well cementing in nature gas hydrates. In this paper, a model to predict cement wellbore temperature was developed by incorporating the complicated interactions between temperature and cement hydration reaction. The model established the relationship between degree of cement hydration and wellbore temperature based on the cement hydration reaction kinetics. Coupled with differential method and numerical calculation, the influence of wellbore temperature on NGH was analyzed during the cementing process. The newly developed model was used to predict the field performance. Model predicted data and field data are within 10.0%. By accurately predicting the change of NGH with wellbore temperature during the cementing process, the model in this paper can not only effectively guide the research and development of low hydration heat cement slurry for NGH well but also find and avoid safety hazards in time during the design process of NGH cementing slurry.

Influence of Particle Size Distribution on the Physical Characteristics of Pore-Filling Hydrate-Bearing Sediment

Nature gas hydrates (NGHs) are regarded as a potential alternative energy source due to their huge reserves and wide distribution. According to the geophysical surveys, the pore-filling hydrates occupy a large proportion of the global hydrate reserves, especially for the marine regions. Therefore, with a novel pore-scale 3D morphological modeling algorithm, this study systematically studied the effect of the particle size on the physical characteristics of the pore-filling hydrate-bearing sediment (HBS). The pore system evaluations and permeability simulations were performed by utilizing pore network modeling (PNM), and the thermal and electrical simulations were conducted by utilizing a finite volume method (FVM). The results show that for the HBS with smaller particle size, the average radius of the pores and throats would also be reduced, and the fractal dimension of the pore system would be increased. In addition, with the increasing hydrate saturation, the fractal dimension of the pore system will increase firstly and then decrease. And these parameter evolutions could impact the physical properties correspondingly; specifically, the decreasing particle size in the HBS would reduce the permeability and electrical conductivity of HBS and enhance the apparent thermal conductivity of HBS.