Applied Mechanics and Materials Vol. 733

Abstract: In this paper, several aspects of the improvement of the oil recovery were analyzed theoretically based on the mechanism that equi-fluidity enhances the pressure gradient. These aspects include the increase of the flow rate and the recovery rate, of the swept volume, and of the oil displacement efficiency. Also, based on the actual situation, the author designed the oil displacement method with gathered energy equi-fluidity, realizing the expectation of enhancing oil recovery with multi-slug and equi-fluidity oil displacement method.

Abstract: Yushulin oilfield Fuyang reservoir belongs to typical low porosity and permeability reservoirs. The internal sand body has complex pore structure and serious heterogeneity. The well logging response doesn't change significantly after the reservoir is flooded. In order to improve the identification precision of the water flooded layer, this paper divides the reservoir into the thick reservoir which is mainly to fluvial facies and estuarine dam deposition and the thin and poor reservoir which is mainly to sheet sand and far sand dam two class. The qualitative identification chart of water flooded layer was established. The chart coincidence rate is more than 75 %, providing a strong basis for perforation scheme of infill wells. The research method of the peripheral oilfield flooded layer identification has wide applicability.

Abstract: In order to overcome the disadvantages of rapid acid-rock reaction rate, short penetration distance, and poor acidification results exist in the process of traditional acidification in Putaohua reservoir, this paper has developed research on retarded acidification technique and optimized its formula and injection parameters. With the operations of complex formulation, screening and optimization among main agent, scale-fromingion inhibitor clay stabilizer corrosion inhibitor retardant, a kind of retarded unplugging formula with good combination property suits for environment of high temperature has been developed. According to research, this developed formula system has permeability improving rate of 60% on natural core, suggest good characteristics of corrosion inhibition, retardation and permeability increasing.

Abstract: Due to the particularity of its percolation of low permeability reservoirs, water injection is very difficult and damage to the reservoir, especially the impurities in injection Wells, at the same time affect the injection efficiency, it will ultimately affect the recovery of the reservoir and the oilfield production. So it is necessary to carry out the ingredients and the causes of impurities in injection wells, clearing the Source for different kinds of impurity to provide the basis for reduce the impurity content in injection wells. In this paper, the author analyzed impurities particle size, composition and content in oilfield injection water In Longhop Oilfield through the indoor experiment, and with the comparison between the ion content and composition of the filtered water samples, analyzing the cause of the impurity within the wellbore. Experimental results show that in oil field water injection well, impurities particle size are mainly distributed between 2.6 and 5.4 um, impurity content mainly changes between 0.003746% and 0.017189%, the main ingredients of impurities is Fe₂O₃ and acid insoluble substances (SiO₂). Fe₂O₃ mainly comes from the injection water; acid insoluble substances mainly come from the formation sand production.

Abstract: By using polymer solution with high viscosity, polymer flooding can enhance oil recovery by reducing the mobility ratio of displacing fluid and oil in formation. Therefore, the core of polymer flooding's ground transportation is to keep the viscosity of polymer solution unchanged. According to the process layout of polymer ground transportation, the experimental device was designed and manufactured to determine viscosity loss of pipelines and elbow. We obtained the viscosity loss variation law of the polymer solutions of different concentrations at different flow velocities when they flow through the pipeline and elbow. The experimental results showed that the viscosity of polymer solution will decrease after the polymer solution flow through pipelines and elbow, due to the shear effect. The higher the velocity, the more significant the viscosity loss.

Abstract: Liquid production per unit thickness is the important indicator which reflect production capacity, and it is magnitude is the radio of well’s daily fluid production rate and sandstone thickness. It is an important job for petroleum reservoir engineering to study the effect of different sandstone thickness type combination to liquid production per unit thickness. Each sandstone thickness type has different size of reservoir thickness, porosity, permeability, etc.so the different sandstone thickness type will produce different degrees of influence to the size of liquid production per unit thickness. The relationship between each sandstone thickness radio and liquid production per unit thickness is obtained by studying all kinds of sandstone thickness radio under different liquid production per unit thickness.

Abstract: In order to improve the grade and recovery of antimony, antimony ore in the process of flotation, this exploratory experiment by reagent addition, process selection to realize. The main parameters of the first set of experiments; grinding fineness of 70% lead nitrate, 200g, Black Powder 100g, directly add collector, did not add kerosene decarburization, choose a coarse, two sweep, two fine flotation process; and the second group of experiments the main parameters; grinding fineness of 70% 200g, lead nitrate, xanthene’s, the choice of a coarse, two sweep, two fine flotation process. The combination of two different groups of flotation experiment comparison, makes the antimony ore grade and recovery can be increased.

Abstract: The pale geomorphology of Lower Xingouzui Formation is controlled by synsedimentary faults. The pale geomorphology controls the distribution of depositional systems, the development of underwater distributary channel controlled by groove and structural slope break belt, combination features of underwater distributary channel and mouth bar controlled by sedimentary slope break, beach bar developed in paleo-uplift, shore-shallow lacustrine and semi-deep lake developed in sag zone.

Abstract: Recently, there has been an increased interest in optimizing horizontal multi-frac completion technologies used to complete offshore low permeability reservoirs in Western South China Sea, but the high-risk and high operating costs are the key problems to hold back the application of this technology, so the impact of economic factors should be taken into full account before fracturing design. This paper shows an new optimization approach of fracturing design by considering the relationship between economic aspects, reservoir size and fracturing treatment size, each fracturing stage of horizontal well is approximated by a rectangular drainage areas and the unified fracture design method is used to calculate the dimensionless productivity index, and an Optimal Proppant Index Function is established with maximization of economic profit as the objective function, while the Optimal Proppant Index Function is determined, the optimal fracture volume and parameters would be obtained.

Abstract: The Nanpu 5th construct is in the western part of Huanghua Depression Nanpu Sag of Bohai Bay Basin, was a complicated anticline belt that develops between Jian Dong fault and the downthrown side of the southwestern Zhuang fault and the favorable exploration area is 120km2. On the basis of the region's large number of multi-channel seismic data analysis and interpretation, the trap types, structural characteristics and distribution of local structures between the layers of the region are researched. Interlayer local structures in the area are mainly divided into nose structure and small anticline. The fault zone is a structural high in the region, to promote oil and gas to migrate and accumulate to the low-potential zones that become favorable zones for hydrocarbon accumulation, but the real decisive construct parts of the hydrocarbon accumulation is positive local structure in favorable zones which point out the region for hydrocarbon accumulation.