In this article, the linear and nonlinear shear rheological behaviors of polylactide (PLA)/clay (organophilic-montmorillonite) nanocomposites (PLACNs) were investigated by an Advanced Rheology Expanded System rheometer. The nanocomposites were prepared by master batch method using a twin-screw extruder with poly(ecaprolactone) (PCL) as a compatibilizer. The presence of org-MMT leads to obvious pseudo-solid-like behaviors of nanocomposite melts. The behaviors caused by the formation of a ''percolating network'' derived from the reciprocity among the strong related sheet particles. Therefore, the storage moduli, loss moduli, and dynamic viscosities of PLACNs show a monotonic increase with MMT content. Nonterminal behaviors exists in PLACNs nanocomposites. Besides the PLACNs melts show a greater shear thinning tendency than pure PLA melt because of the preferential orientation of the MMT layers. Therefore, PLACNs have higher moduli but better processibility compared with pure PLA.

In order to explore the applicability of waste engine oil and waste cooking oil used in aged asphalt, the effect of waste engine oil and waste cooking oil on aged asphalt recycling was studied through the analysis of the improvement of its physical, chemical, and rheological properties. Six aged asphalt binders with different aging times were obtained by indoor test simulation using the Thin Film Oven Test at 163 °C. Then, waste engine oil and waste cooking oil with five different dosages were added to investigate improvement performances. The results clearly demonstrated that waste engine oil and waste cooking oil could soften and recover the work ability of aged asphalt effectively. Furthermore, the physical, chemical, and rheological performances of six aged asphalts could be improved to normal level of virgin asphalt if the content of waste engine oil or waste cooking oil was suitable. The rheological properties of aged asphalt with waste cooking oil had better improvement than that with waste engine oil. Overall, the good applicability would provide waste oil a much wider service range in asphalt pavement recycling field. It also provided a method of developing new rejuvenating agent with the two waste oils to achieve complex synergism effect. Moreover, it realized the waste cyclic utilization and environmental protection.

No abstract

No abstract

The Triassic Baikouquan Formation in the Junggar Basin has developed a large number of dense sandstore conglomerate reservoirs, which belong to ultra-low permeability and ultra-low permeability refractory reservoirs. In recent years, the productivity of single well is improved by selecting potential production wells for multi-stage steering fracturing. In order to realize the forced steering of fractures, it is very important to study the sealing pressure of temporary plugging agent. According to the actual needs of Baikouquan steering fracture, the net pressure model of steering fracture is established. The net pressure value in the seam is calculated according to the change of ground stress after steering, then calculated the minimum temporary plugging agent sealing pressure needed for a single fracture. Based on the net pressure model, the corresponding software is developed and applied to the field. The practical application effect is good, which provides economical and effective technical technical support for the continuous and stable production of low permeability oil field.

No abstract

The delayed polymer crosslinking technique is used for profile control in deep fractured reservoirs with low permeability. Its mechanism, formulation and injection process have been researched for reservoirs with low permeability, low porosity, heterogeneity and both natural and artificial fractures. The weak gel has a dual function for both profile control and polymer flooding. It is an effective method for improving the flooding efficiency of fractured reservoirs with low permeability and low yield. P. 169

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractFoam combination flooding is one of the most capable tertiary oil recovery techniques. For the pilot test of foam combination flooding performed in Sa-Nan, Daqing, gas hydrates affect the normal gas injection badly. The designed gas injection is 182 days, however, due to the influence of gas hydrates, only 59 days of gas injection is conducted. The injected gas is just about 36 days' work in the design. Based on the pilot test in Sa-Nan, this paper elucidates the structure, phase state and forming condition of gas hydrates and proposes a number of effective measures to prevent and remove the formation of gas hydrates in the process of foam combination flooding. Two models for predicting the forming condition of gas hydrates for foam combination flooding are presented in this paper. Phase-equilibrium-constant method is proved to be more accurate and reliable than empirical graphic method and is recommended for use in research work and field practice to determine the forming condition of gas hydrates in foam combination flooding. With this method, the forming condition of gas hydrates in Sa-Nan pilot is calculated. The result shows that gas hydrates will generate at temperature lower than 73.4°F. Three ways are proved effective to prevent the formation of gas hydrates for foam combination flooding, which are reducing the water content of natural gas, improving the injection technology to avoid the contact of water with gas and adding certain suitable inhibiting agent. Heating, lowering pressure and adding deicing agent are suggested as the three good measures to get rid of the plugging in injection pipelines caused by gas hydrates for foam combination flooding. SI Metric Conversion Factorspsia × 6.894757* E+00= KP a (°F -32*)×5*/9* = °C * Conversion factor is exact.