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The development of anti-rhythmic carbonate reservoirs in the Middle East often encounters challenges such as water hold-up and reverse coning during the water injection process, leading to premature water breakthrough and various water-out issues. The unclear understanding of these phenomena, attributed to strong reservoir heterogeneity, results in a relatively low recovery degree in water injection development. This paper investigates the mechanisms behind water hold-up and reverse coning phenomena, offering detailed solutions. Numerical models of the oil reservoirs were developed, and an extensive study of influencing factors, including reservoir types, Kv/Kh, water injection pressure differential, wettability, and perforation position, was conducted to unveil the underlying mechanisms. Key findings indicate that the water hold-up phenomenon is influenced by capillary force barriers due to wettability and high-perm streaks, while the reverse coning phenomenon depends on the combined forces of gravity, capillary force and downward production differential among which downward production differential is the dominant factor compared to capillary force and gravity. The study also proposes a differential perforation principle tailored to different water-out types to enhance vertical sweep efficiency. The differential perforation principle is as follows: the optimal perforation position is at top layer and the optimal perforation length approximately accounts for 1/4 of the total oil layer thickness for water-out in bottom; the avoidance perforation height in top accounts for 1/6 of the total oil layer thickness and the optimal perforation length approximately accounts for 1/2 of the total oil layer thickness for water-out in top; the avoidance perforation height in top and bottom accounts for 1/5 and 2/5 of the total oil layer thickness respectively for water-out in both top and bottom.

Fly ash (FA) and slag could improve the performance of glazed hollow bead (GHB) thermal insulation mortar, but little research touched on how the FA and slag affect its performance and optimize its component contents. In this study, an experimental and statistical investigation is conducted to analyze the influences of FA and slag variables on the performance of GHB mortar based on the response surface methodology (RSM). The predicted model was proved statistically significant in terms of the fluidity, compressive strength, flexural strength, and thermal conductivity. Then, the validated model was used to identify the critical parameters and discuss their mechanisms of action. It can be found that (i) FA plays a significant role in fluidity and compressive and flexural strength owing to its morphological and physical filler effects; (ii) slag has an obvious influence on compressive strength and thermal conductivity due to its microaggregate effect. Finally, optimization design was conducted using the desirability approach of RSM to give the optimal component of 20.73% FA and 21.49% slag. The predicted combination was validated by confirmatory tests within an error of 1.52%. This study provides a feasible and effective solution for optimizing GHB thermal insulation mortar to achieve higher performance.

In order to enhance the development efficiency of thick and complex carbonate reservoirs in the Middle East, a case study was conducted on M oilfield in Iraq. This study focused on reservoir characterization, injection-production modes, well pattern optimization, and other related topics. As a result, key techniques for the high-efficiency development of thick carbonate reservoirs were established. The research findings include the following: (1) the discovery of hidden "low-velocity" features within the thick gypsum-salt layer, which led to the development of a new seismic velocity model; (2) the differential dissolution of grain-supported limestones is controlled by lithofacies and petrophysical properties, resulting in the occurrence of "porphyritic" phenomena in core sections. The genetic mechanism responsible for reversing petrophysical properties in dolostones is attributed to "big hole filling and small hole preservation" caused by dense brine refluxing; (3) fracture evaluation technology based on anisotropy and dipole shear wave long-distance imaging was developed to address challenges associated with quantitatively assessing micro-fractures; (4) through large-scale three-dimensional physical models and numerical simulations, it was revealed that water–oil displacement mechanisms involving "horizontal breakthrough via hyper-permeability" combined with vertical differentiation due to gravity occur in thick and heterogeneous reservoirs under spatial injection-production modes; (5) a relationship model linking economic profit with well pattern density was established for technical service contracts in the Middle East. Additionally, an innovative stepwise conversion composite well patterns approach was introduced for thick reservoirs to meet production ramp-up requirements while delaying water cut rise; (6) a prediction technology for the oilfield development index, considering asphaltene precipitation, has been successfully developed. These research findings provide robust support for the efficient development of the M oilfield in Iraq, while also serving as a valuable reference for similar reservoirs' development in the Middle East. [ABSTRACT FROM AUTHOR]

To improve the traffic efficiency of bus at a group of intersections and reduce their delay, this paper develops a speed guidance strategy for buses under travel time control at intersection groups. The approach considers the influence of bus departure time, bus station arrival rate, and bus station dwell time. Simulation experiments are carried out on three consecutive intersections along Jinshan Avenue in Fuzhou, China. Results show that the average travel time of buses, the average delay of buses, and the average delay per capita in the priority direction are reduced by 5.5%, 9.9%, and 9.4%, respectively. The optimal rate of the average number of bus stops reached 15.2%. The indicators of the non-priority direction of social vehicles are not significantly affected. It shows that the efficiency of buses has improved after implementing the speed guidance strategy at the intersection groups without affecting the social vehicles as far as possible. [ABSTRACT FROM AUTHOR]

【Background and objective】 Continuously pumping groundwater over the past half century for crop production in northern China has resulted in a series of environmental and ecological issues. The shortage of freshwater resources has become a bottleneck in socioeconomic development of this region. Improving groundwater management is important not only to its sustainable use but also to keeping ecosystems in this region function. Achieving this goal needs to understand how groundwater dynamics responds to environmental changes, as well as its consequent spatial distribution. The objective of this paper is to demonstrate how the SWAT model can be used to evaluate groundwater resource and its spatial distribution at regional scale. 【Method】 We took Jinghe basin as an example. Groundwater flow, surface runoff and their underlying driving factors were simulated using the SWAT model. Monthly measured runoff from hydrological stations at Jingchuan, Yangjiaping and Zhangjiashan was used to calibrated the model parameters; the calibrated model was then used to evaluate changes in groundwater depth, shallow groundwater resource, as well as extractable groundwater in the basin. 【Result】 The calibrated model correctly reproduced the groundwater dynamics in the basin, with R2 and NS between the measured and simulated runoff being 0.83 and 0.71, respectively. The distribution of shallow groundwater depth varied widely in the basin, but it has been in decline. From 2009 to 2016, the shallow groundwater resource had reduced by 6.59 billion m3, decreasing at an average rate of 0.051 billion m3/month. We found that the average recharge rate to the groundwater in the basin was 0.344 billion m3/a, the average subsurface runoff modulus was 0.21 L/(s·km2), and the extractable groundwater resource was 0.189 billion m3/a. 【Conclusion】 The SWAT model is capable of modelling regional surface runoff and shallow groundwater dynamics. It can be used to evaluate groundwater resources and the response of groundwater dynamics to environmental change.