Environmental response nanosilica for reducing the pressure of water injection in ultra-low permeability reservoirs

2017 ◽  
Vol 19 (12) ◽  
Author(s):  
Peisong Liu ◽  
Liyong Niu ◽  
Xiaohong Li ◽  
Zhijun Zhang
Keyword(s):  
Water Injection ◽  
Low Permeability ◽  
Environmental Response ◽  
Low Permeability Reservoirs

The Research and Evaluation of Finely Layered Water Injection Standard in Low-Permeability Reservoirs - A Case from Block A in one Low-Permeability Reservoir

2014 ◽  
Vol 1073-1076 ◽  
pp. 2310-2315 ◽  
Author(s):  
Ming Xian Wang ◽  
Wan Jing Luo ◽  
Jie Ding
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Injection Pressure ◽  
Injection Rate ◽  
Low Permeability ◽  
Reservoir Permeability ◽  
Engineering Parameters ◽  
The Common ◽  
Common Problems ◽  
Low Permeability Reservoirs

Due to the common problems of waterflood in low-permeability reservoirs, the reasearch of finely layered water injection is carried out. This paper established the finely layered water injection standard in low-permeability reservoirs and analysed the sensitivity of engineering parameters as well as evaluated the effect of the finely layered water injection standard in Block A with the semi-quantitative to quantitative method. The results show that: according to the finely layered water injection standard, it can be divided into three types: layered water injection between the layers, layered water injection in inner layer, layered water injection between fracture segment and no-fracture segment. Under the guidance of the standard, it sloved the problem of uneven absorption profile in Block A in some degree and could improve the oil recovery by 3.5%. The sensitivity analysis shows that good performance of finely layered water injection in Block A requires the reservoir permeability ratio should be less than 10, the perforation thickness should not exceed 10 m, the amount of layered injection layers should be less than 3, the surface injection pressure should be below 14 MPa and the injection rate shuold be controlled at about 35 m3/d.

Research on Flow Units of Extra-Low Permeability Reservoirs in Fault Block Sheng554 of Shengping Oilfield

2013 ◽  
Vol 295-298 ◽  
pp. 3162-3165
Author(s):  
Lu Lu Zhou ◽  
Zi Nan Li ◽  
Jun Gang Liu ◽  
Yan Yun Zhang ◽  
Guang Qiang Shu
Keyword(s):  
Fluid Flow ◽  
Water Injection ◽  
Type A ◽  
Low Permeability ◽  
Type B ◽  
Flow Units ◽  
Fault Block ◽  
Remaining Oil ◽  
Type C ◽  
Low Permeability Reservoirs

Taking the example of the fourth member of the Lower Cretaceous Quantou formation reservoirs in fault block Sheng554 of Sanzhao sag, this article discusses the methodology of flow units in extra-low permeability reservoirs. The research on flow units in such reservoirs can be divided into two ranks, one is to determine the distribution of seepage barriers and inner connected sands， the other is to analyze the differentia of fluid flow in the inner connected sands so as to subdivide the flow units. The result shows that the pelitic barriers are rather developed in fault block Sheng554. Through the analysis of differentia of fluid flow, according to the value of flow zone index (FZI), the inner connected sands can be classified into three types of flow units, among which type A with FZI value greater than 1.0 has better permeable property and higher intensity of water injection, and the ability of permeability and water injection of type B with FZI value between 0.5 and 1.0 takes the second place, and type C is the worst flow unit with the worst permeable property and intensity of water injection with FZI value less than 0.5. Among the three types of flow units, type A poorly develops, while type B and type C develops well. The research on flow units can provide reliable geologic bases for forecasting the distribution of remaining oil in extra-low permeability reservoirs and for developing remaining oil in the study area.

scholarly journals Semi-analytical modeling of advanced water injection in low permeability reservoirs under non-Darcy-flow condition

2019 ◽  
Vol 11 (5) ◽  
pp. 168781401984676 ◽  
Author(s):  
Chengyong Li ◽  
Jing Yang ◽  
Jianwen Ye ◽  
Jun Zhou ◽  
Ran Zhang ◽  
...  
Keyword(s):  
Flow Condition ◽  
Analytical Modeling ◽  
Water Injection ◽  
Darcy Flow ◽  
Low Permeability ◽  
Low Permeability Reservoirs

The Research of Layer System Subdivision and Adjustment Methods in YSL Block of the Low Permeability Reservoirs

2013 ◽  
Vol 274 ◽  
pp. 153-156
Author(s):  
Rong Hua Li ◽  
Jun Ting Zhang ◽  
Cheng Lin Zhang ◽  
Huan Huan Zhang ◽  
Peng Qu
Keyword(s):  
Water Injection ◽  
Oil Field ◽  
Thin Layers ◽  
Water Flooding ◽  
Low Permeability ◽  
Layer System ◽  
Oil Distribution ◽  
Major Adjustment ◽  
Low Permeability Reservoirs ◽  
Oilfield Development

Layer system subdivision and adjustment is applied in oilfield development to ease the contradiction in inner-layer and interlayer and implement separated layer water flooding well, which is a major adjustment measure to improve developing effects. YSL is a typical low-permeability oil field, whose petrophysics is poor, and which exist many problems, such as apparent contradictions between layers, and poor development effects through separated zone water injection and so on. In this article, the thickness of barriers, injection profile, permeability contrast and remaining oil distribution are analyzed comprehensively. So a reasonable method is also proposed. Much weakness that factors are not comprehensive in adjustment method and that the problems in the development process are not accurately reflected is overcome, which exists in the past methods. The adjustment means can utilize poor thin layers better, reduce invalid water injection and ease the contradictions between layer, and oilfield development effects are improved eventually. It is a reference and guidance for other blocks or oilfield which exist the same problems.

Permeability Limits of Advanced Water Injection Technology in Low Permeability Reservoirs

2016 ◽  
Author(s):  
Shuai Wang ◽  
Ji Tian ◽  
Xianhong Tan ◽  
Ling Wang ◽  
Shaohui Zhang
Keyword(s):  
Water Injection ◽  
Low Permeability ◽  
Injection Technology ◽  
Low Permeability Reservoirs

Best Practices in Development and Production Optimization of Offshore Low Permeability Reservoir

2021 ◽  
Author(s):  
Lijian Zhang ◽  
Panpan Tian ◽  
Chuanheng Xing ◽  
Ruiting Bai ◽  
Yanjun Yin ◽  
...  
Keyword(s):  
Water Injection ◽  
Liquid Extraction ◽  
Oil Wells ◽  
Production Optimization ◽  
Low Permeability ◽  
Electric Pump ◽  
Efficient Operation ◽  
Well Pattern ◽  
Geological Conditions ◽  
Low Permeability Reservoirs

Abstract The development effect of low permeability reservoirs of offshore Shahejie Formation in China is poor with fast formation pressure drop, rapid production decline and numerous abnormal wells due to the influence of low permeability, strong heterogeneity, ultra-high reservoir temperature and pressure and high wax and asphaltene content. To overcome these difficulties, this paper takes geological conditions, reservoir potential, stimulation technology and actual wells situation into consideration on the basis of the reservoir performance research, and gives full play to the integration of reservoir and mechanical recovery. A set of production enhancement and efficiency improvement technologies has been formed, including moderate periodic water injection based on pressure fluctuation theory, liquid extraction optimization for low permeability fields, modified compound plugging removal technology, small flowrate and broad width electric pump selection technology, and pump stuck early warning technique to achieve the efficient development of offshore low-permeability oilfields. Moderate periodic water injection not only makes full use of the imbibition effect to achieve the equilibrium displacement, but also avoids the water channeling in fracture area; eight main controlling factors are used to classify and evaluate the liquid extraction potential and select the well group at level-1 for the workover with the effect of daily oil increase of 42 m3; modified compound plugging removal technique completely removes the pollution and plugging of the formation and the wellbore to release the potential of the oil wells to the greatest extent and cumulative oil increase of 6 well times is expected to be 12.44×104 m3; small flowrate and broad width electric pump selection technology applied for more than 30 well times improves the adaptability of the pumps substantially and extends the pump inspection cycle to 857 days; real-time pump stuck warning technique through the dual pattern of analyzing both conventional and high-frequency data guarantees the efficient operation of oil wells. The technologies in this paper have been applied in the target low-permeability field with daily oil production of 429 m3, oil recovery rate of 1.1%, natural decline rate drop year by year and the expected recovery factor of 20.9% under current well pattern. The key technologies in this paper have improved the target reservoir development effect significantly and provided important reference significance for other offshore low-permeability reservoirs development.

Review and Outlook on Technologies for Developing PetroChina Low-Permeability Reservoirs

2013 ◽  
Vol 838-841 ◽  
pp. 1869-1872
Author(s):  
Xiu Juan Fu ◽  
Shu Hong Ji
Keyword(s):  
Water Injection ◽  
Horizontal Wells ◽  
Low Permeability ◽  
Future Technology ◽  
The Past ◽  
Low Permeability Reservoirs ◽  
Technology Trend

The technologies applied to develop PetroChina low-permeability reservoirs are summarized in the past more than 20 years. These technologies include water injection in advance, waterflood pattern optimization, fracturing and horizontal wells, etc. In addition, future technology trend is also forecasted.

Optimized Cyclic Water Injection Strategy for Oil Recovery in Low-Permeability Reservoirs

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Xiaofei Sun* ◽  
Yanyu Zhang ◽  
Jie Wu ◽  
Mengke Xie ◽  
Hang Hu
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Tracer Tests ◽  
Oil Prices ◽  
Fuzzy Comprehensive Evaluation ◽  
Low Permeability ◽  
Operational Parameters ◽  
Recovery Method ◽  
Low Permeability Reservoir ◽  
Low Permeability Reservoirs

With the worldwide decline in conventional oil production, tremendous unconventional resources, such as low-permeability reservoirs, are becoming increasingly important. Cyclic water injection (CWI) as an oil recovery method has attracted increasing attention in the present environment of low oil prices. However, the optimal CWI strategy is difficult to determine for a mature oilfield due to the involvement of multiple wells with multiple operational parameters. Thus, our main focus in this paper is to present a novel and systematic approach to optimize CWI strategies by studying a typical low-permeability, namely, reservoir G21. To this end, a comprehensive method that combines the advantages of streamline simulation and fuzzy comprehensive evaluation (FCE) was proposed to identify water channeling in the reservoir. Second, the reliability of the method was verified using tracer tests. Finally, a new hybrid optimization algorithm, the simulated annealing-genetic algorithm (SAGA), coupled with a reservoir simulator was developed to determine an optimal CWI strategy for the low-permeability reservoir. The results show that the CWI technique is viable as a primary means in the present environment of low oil prices to improve the waterflood performance in low-permeability reservoirs. The oil recovery of the most efficient strategy increases by 6.8% compared to conventional waterflooding. The asymmetric CWI scheme is more efficient than the symmetric CWI scheme for the low-permeability reservoir.

A Study of Seepage Characteristics of Unsteady Waterflooding Development for Fractured Ultra-Low-Permeability Reservoir

2021 ◽  
Author(s):  
Qing Liu ◽  
Xiangfang Li ◽  
Jian Yang ◽  
Sen Feng ◽  
Minxia He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Water Injection ◽  
Injection Rate ◽  
Low Permeability ◽  
Tensor Model ◽  
Capillary Imbibition ◽  
Low Permeability Reservoir ◽  
Water Cut ◽  
Low Permeability Reservoirs

Abstract Unconventional fractured ultra-low-permeability reservoirs play an important role in continental sedimentary basins in China, and their formation characteristics and seepage laws are greatly different from that of traditional reservoirs. In this paper, the influence of microfractures and unsteady waterflooding on the productivity of fractured ultra-low permeability reservoirs are studied deeply. The reservoir parameters used in the study are from an actual fractured ultra-low-permeability reservoir in Ordos Basin, where microfractures are developed but macroscopic fractures are not. The microfractures have a small opening and are widely distributed in the reservoir, so the reservoir numerical simulation model adopts the equivalent continuous matrix model to simulate waterflooding. On one hand, the physical model of micro-fractured reservoir and the permeability tensor model of the equivalent continuous matrix are established. The results show that the existence of microfractures can increase the permeability of matrix by 1.4 times. On the other hand, an ideal heterogeneous numerical simulation model composed of pure matrix and equivalent continuous matrix considering microfracture is established according to actual geological parameters of the fractured ultra-low-permeability reservoir. To simulate and compare the unsteady waterflooding and continuous waterflooding development in 10-year development under the condition of constant annual injection rate, the results indicate that unsteady waterflooding development make higher productivity and lower water cut and lower formation water saturation than that of continuous waterflooding. By conducting unsteady waterflooding development simulation for sensitivity analysis, the results demonstrate that the greater the capillary force, the better the role of capillary imbibition in a certain range, meanwhile, the unsteady waterflooding has the best exploitation effect when the value of water injection cycle time is 100 days and the fluctuation amplitude of water injection rate is 1. At the above situation, the displacement and capillary imbibition and pressure disturbance achieve the desired effect of reducing water cut and increasing oil production.

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