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Hongjie Wang ¹, Jianen Gao ¹, Hong Wang ², Li Liu ¹

Affiliations
1 College of Water Resources and Architectural Engineering, Northwest A & F University, 712100, Yangling, CN
2 Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, CN

Abstract

The impact of the soil and water conservation measures in the process of river runoff and sediment discharge has caused wide attention. The Wei River, which has a serious water shortage and a high sediment concentration, was selected as the research watershed. Based on the measured data of rainfall, runoff and sediment, the statistical methods of wavelet analysis, Mann-Kendall test, and double cumulative curve were used to analyse the impact of soil and water conservation on runoff and sediment environment in Wei River Basin. The results showed that the river transported sediment increased during 1930s-1970s, and the average increasing rate was about 0.035×108 t/a. And the river transported sediment decreased after 1970s and the average decreasing rate was about 0.047×108 t/a. The relationship between water and sediment in Wei River Basin can be divided into two phases i.e., from 1940-1970s and after 1970s. From the 1940s to 1970s, there was less human activity, such as soil and water conservation, in the Wei River Basin, so the runoff and sediment yield changes were mainly affected by climate change. When the runoff was larger, the sediment load was larger and when the runoff was smaller, the sediment load was also smaller. After 1970s, large-scale measures of soil and water conservation were developed, which has great impact on soil erosion and sediment yield of basin and resulted in changing of laws between the runoff and sediment load. When the runoff was larger, the sediment load was smaller and when the runoff was smaller, the sediment load was also smaller, especially after 1997. It was concluded that the soil and water conservation play an important role in the reduction of the sediments of river. And when the comprehensive treatment reaches a certain level of governance, it has positive environmental benefits for both sediment and runoff.

Keywords

Soil and Water Conservation, Runoff Sediment, Mann-Kendall Test, Wavelet Analysis.

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Li Liu ¹, Jing Li ¹, Ya Gong ¹, Yaiming Pi ², Libo Yang ³

Affiliations
1 Northeast Petroleum University, Daqing 163 318, CN
2 EnerTech-Drilling & Production Co., CNOOC, Tanggu Tianjin 300 457, CN
3 The second operation area of gas production branch of Daqing Oilfield Co, Ltd., Daqing 163 318, CN

Abstract

In view of a certain block of First Production Plant in Daqing Oilfield, this paper conducted physical simulation experiments of three hydrophobic associated polymers flooding which is in two conditions that equal concentration and equal viscosity after polymer flooding. As a result, injecting equals the multiples of pore volume under equal concentration. Enhanced recovery effect range: 20.73% of Huading I hydrophobic associated polymer flooding is the largest; 12.22% of Haibo BI hydrophobic associated polymer flooding is the most un-conspicuous. Injected equal the multiples of pore volume under equal viscosity. Enhanced recovery effect range : 20.73% of Huading I hydrophobic associated polymer flooding is the largest; 14.48% of Haibo BI hydrophobic associated polymer flooding is still the most un-conspicuous. Combined with the indoor experimental result, it can be seen that the poly table agent of Huading I is the best of the three kinds in driving the residual oil after polymer flooding, and its effect is the most obvious.

Keywords

Physical Simulation Experiments, Hydrophobic Associated Polymers, Equal Concentration, Equal Viscosity, Enhanced Recovery Effects.

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Li Liu ¹, Yanming Pi ², Ying He ¹, Zhenxing Zhang ³, Zetian Meng ⁴, Zhipeng Dai ¹

Affiliations
1 Northeast Petroleum University, Daqing 163 318, CN
2 EnerTech-Drilling & Production Co., CNOOC, Tanggu 300 457, CN
3 CNOOC EnerTech-Safety & Environmental Protection Co., Toutai Company of Daqing Oil field.166 512, CN
4 No.6 Oil Production Company of Daqing Oilfield Co., Ltd. 163 114, CN

Abstract

The offshore oilfield are mostly viscous oil reservoirs. Tertiary oil recovery technology is mainly composed of the injection of the polymer solution. It is a problem to be solved for researchers to improve the oil recovery further. In the current study, we designed the heterogenetic physical model for the typical offshore area. The comparative study was carried out by experiments. In the meantime, we discussed the plan optimization of the chemical flooding after the polymer flooding in an offshore oilfield and evaluated the production level under different injection mode. The experimental results proved that the alkaline-polymer flooding is the preferred mode of chemical flooding after the polymer flooding in offshore typical area.

Keywords

Viscous Oil, Polymer Flooding, Chemical Flooding, Alkaline-Polymer Flooding.

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Li Liu ¹, Jing Li ¹, Naiyuan Zhang ², Jinsheng Hao ³, Yanfen Sui ⁴, Yanfu Pi ¹

Affiliations
1 Northeast Petroleum University, Daqing 163 318, CN
2 Daqing Oilfield Production Technology Institute 163 453, CN
3 The Second Oil Production Plant of Daqing Oilfield Co., Ltd. 163 414, CN
4 No.1 Oil Production Company of Daqing Oilfield Co., Ltd. 163 000, CN

Abstract

Aiming at the problem of large precision error of oil saturation monitoring in the current physical simulation process, a self-made oil saturation monitoring system was used to measure oil saturation distribution in the displacement process of Huading I polymer surfactant and Haibo BI polymer surfactant flooding after polymer flooding. And the system is based on the theory of rock electricity and improved method of conventional saturated oil steady-state method. Under the injection of the same PV number, it is obvious that Haibo polymer surfactant is easier to use the unswept area of polymer flooding in various layers. The result shows that Haibo BI polymer surfactant can greatly expand the sweep efficiency of each layer, and Huading I polymer surfactant has a strong oil displacement efficiency.

Keywords

Physical Simulation, Polymer Surfactant Flooding, Oil Saturation Distribution, Sweep Efficiency, Oil Displacement Efficiency.

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