Automatic Measurement and Monitoring Technology for Oil Well

Measurement technology of oil well develops and improves constantly at present. Reducing operation cost and energy consumption and improving efficiency of labor provides reliable technical guarantee for simplifying and optimizing ground process system. According to the needs of parametric measurement and monitoring for oil well, the paper combines with actual situation of the second factory in Dagang Oilfield, the second factory proposes the research on automatic measurement and monitoring technology for wireless oil well and application project, and scientific and information department in Dagang Oilfield ratifies the project. The paper studies automatic measurement and monitoring technology for wireless oil well, and evaluates the economic and social benefit

Study on flow unit division and production dynamics of tight sandstone reservoir in Huaqing oilfield

758-764In this paper, the Chang 6 ultra-low permeability reservoirs in Huaqjing area of Ordos Basin are studied. The reservoir is divided into four types of flow units by using Q-type multi-parameter clustering analysis and SPSS statistical analysis software. The characteristics of reservoir physical properties, sedimentary characteristics, capillary pressure curve and production dynamics were analyzed. The rationality of the results were verified from the static and dynamic points of view. Results show that I type flow unit has good reservoir properties and development effect is fast. The main development target is to maintain long-term stability. The distribution areas of II and III types are large, and cover the main production layer of oil field development and the remaining oil enrichment area. The reservoir properties of the IV type flow unit are worst, and the development is difficult. Efficient development of such reservoirs through the scientific division of the flow unit is important and of practical significance

Advances in multifield and multiscale coupling of rock engineering

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Experimental Investigation of Pore Structure and Movable Fluid Traits in Tight Sandstone

Whether the variation of pore structures and movable fluid characteristics enhance, deteriorate, or have no influence on reservoir quality has long been disputed, despite their considerable implications for hydrocarbon development in tight sandstone reservoirs. To elucidate these relationships, this study systematically analyzes pore structures qualitatively and quantitatively by various kinds of direct observations, indirect methods, and imaging simulations. We found that the uncertainty of porosity measurements, caused by the complex pore-throat structure, needs to be eliminated to accurately characterize reservoir quality. Bulk water was more easily removed, while surface water tended to be retained in the pores, and the heterogeneity of pore structures was caused by the abundance of tiny pores. The rates of water saturation reduction in macropores are faster than those for tiny pores, and sandstones with poor reservoir quality show no marked descending of lower limits of movable pore radius, indicating that the movable fluid would advance exempted from the larger pores. This study suggests that the deterioration of reservoir quality is strongly affected by the reduction of larger pores and the aqueous phases tended to remain in the tiny pores in the forms of surface water

Role of Gas Viscosity for Shale Gas Percolation

Viscosity is an important index to evaluate gas flowability. In this paper, a double-porosity model considering the effect of pressure on gas viscosity was established to study shale gas percolation through reservoir pressure, gas velocity, and bottom hole flowing pressure. The experimental results show that when pressure affects gas viscosity, shale gas viscosity decreases, which increases the percolation velocity and pressure drop velocity of the free state shale gas in matrix and fracture systems. And it is conducive to the desorption of adsorbed shale gas and effectively supplemented the bottom hole flowing pressure with the pressure wave propagation range and velocity increasing, so that the rate of pressure drop at the bottom of the well slows down, which makes the time that bottom hole flowing pressure reaches stability shortened. Therefore, the gas viscosity should be fully considered when studying the reservoir gas percolation

The impacts of diagenetic facies on reservoir quality in tight sandstones

The impact of diagenetic minerals and the characteristics of pore structures on reservoir qualities has been studied separately in the past years. However, the difference in the reservoir quality with different pore structures and having same or similar content of diagenesis minerals has not been ascertained. In this study, based on the core samples derived from Chang 6 member in the Ordos basin, various tests were performed to examine the sandstone diagenesis and investigate the pore structure. The results showed that there were five diagenetic facies by diagenetic and pore structure analyses, and the best reservoir quality rocks were found to have relatively low percentage of illite, carbonate cement, pore-filling chlorite, authigenic quartz, and relatively high proportion of intergranular pores. Smectite-to-illite reaction and chemical compaction were main sources for quartz cementation at 60–120°C, and carbonate content was found to increase toward source rocks. The porosity depth trends significantly affected the diagenetic facies. The diagenetic and the pore structure pathways of various diagenetic facies were reconstructed by integrated petrographic, mineralogical, and pore system data. This study provides insights into the porosity evolution and diagenetic pathways of various diagenetic facies of tight sandstones, and the influence of diagenesis minerals and pore structures on their reservoir quality

Microscopic pore structure characteristics and logging response characteristics of different diagenetic facies reservoirs and their impact on the distribution of high quality reservoirs

567-579Distribution of high quality diagenetic facies is controlled jointly by sedimentary facies, diagenesis and pore structure, and especially throat distribution is the main factor for controlling sandstone reservoir permeability.  Reservoir in the hydromica cementation--residual intergranular pore facies and hydromica cementation--feldspar corrosion facies is distributed mainly in semi-deep lacustrine gravity flow composite channel turbidites; fine--tiny throats are developed, the connectedness of pore throats is good, and their percolation capacity is the best; oil and water are of relatively uniform seepage flow, and the oil and gas in pores are produced via throats extremely easily. The reservoir in the chlorite cementation facies and hydromica cementation weak corrosion facies is located in the margin of branch channels and distributed in island shape; the pore throat radius is small but is distributed uniformly, and the percolation capacity of pore throats is medium to bad.  Reservoir in the carbonate cementation facies and carbonate + hydromica cementation facies is developed mainly between branch channels; the development degree of the pore structure is low, throats are fine and small, and pore throat connectedness is bad; the oil and gas rich in pores are difficult to pass small throats, and the recovery ratio is low

Cybersecurity For Digital Manufacturing

Digital manufacturing aims to create highly customizable products with higher quality and lower costs by integrating Industrial Internet of Things, big data analytics, cloud computing, and advanced robots into manufacturing plants. As manufacturing machines are increasingly retrofitted with sensors as well as connected via wireless networks or wired Ethernet, digital manufacturing systems are becoming more accessible than ever. While advancement in sensing, artificial intelligence, and wireless technologies enables a paradigm shift in manufacturing, cyber-attacks pose significant threats to the manufacturing sector. This paper presents a review of cybersecurity in digital manufacturing systems from system characterization, threat and vulnerability identification, control, and risk determination aspects as well as identifies challenges and future work

The Influential Factors and Characteristics of Tight Sandstone Gas Reservoir: A Case Study in Ordos Basin in China

To analyze the impact of the factors on physical properties and the mechanism of tightness as well as favorable accumulation space of tight sandstone reservoir, comprehensive analysis is conducted using various kinds of experiments. The results show that the predominant rock type is medium-coarse grained lithic quartzarenite, and the main accumulating space is the dissolved secondary pores. Reservoir pore-throat structures can be divided into four categories. Based on morphologies and parameters which derived from capillary pressure curves, the physical properties rank in the following descending sequence: Type I>Type II>Type III>Type IV. The reservoir quality is influenced by both sedimentation and diagenesis synthetically. The underwater distributary channel is the dominant space for favorable reservoir. Compaction and cementation play dominant roles in the reduction of permeability. The loss of primary pores caused by both those diagenesis are 20.52% and 16.91%, respectively. Secondary pores formed by dissolution improve the reservoir quality by increase the porosity (2.68%). This suggests that weak diagenesis greatly contributes to the improvement of reservoir quality

Quantitative Study of Residual Oil Distribution during Water Flooding through Digital Core Analysis

The character of residual oil formed during water flooding, one important technique to enhance oil recovery, is helpful to further study permeability and recovery in tight sandstone oil reservoirs. In this paper, we take a tight sandstone reservoir in Ordos Basin as the research object and use in situ displacement X-CT scanning technology to analyze the dynamic characteristics of oil during water flooding. Firstly, core pore radius and oil storage space radius were measured from digital cores which are acquired in different water flooding stages by X-CT scanning technology. Secondly, analytical and evaluation methods were established to describe fluid distribution in the pore space of the core in different water flooding stages based on curve similarity. Finally, by numerical results, we analyzed the oil distribution features in the process of water flooding for core samples. In this paper, the oil distribution characteristics during water flooding are revealed based on digital core analysis. Also, a quantitative evaluation method is given to provide theoretical guidance