Based on the panel data of Jinzhou, Panjin, Songyuan, Daqing, Yangzhou, Dongying and other 20 oil and gas resource-based cities from 2010 to 2018, combined with DEA-SBM model and Malmquist-Luenberger index, using DEA-SOLVERPro 5.0 and MaxDEA software. This paper evaluates the green growth efficiency of oil and gas resource-based cities from static and dynamic perspectives.The results show that the average static efficiency of green growth of the main oil and gas resource-based cities in China does not reach 1, there is efficiency loss, and it does not reach Pareto optimum.The static efficiency of green growth of the eastern oil and gas resource-based cities is higher than that of other regions, which is in line with the law of the Environmental Kuznets Curve. The environment has been improved. More than half of the oil and gas resource-based cities have a dynamic efficiency value of green growth greater than 1, and the development trend of green growth is better.
In the development of multi-layer co-production heterogeneous reservoirs, problems such as serious inter-layer heterogeneity and interference always exist, resulting in an unclear understanding of inter-layer production. A clear understanding of the interference mechanism and influence of main controlling factors of multi-layer heterogeneous reservoirs on the production of small layers is the key to the effective development of the reservoirs. On the basis of clarifying the main controlling factors affecting the production of multi-layer heterogeneous reservoirs, this paper developed a multi-pipe parallel displacement experiment system to carry out indoor heterogeneous reservoir multi-layer water injection flooding experiments. Combined with dynamic and static parameters, the experiments simulated and evaluated the effects of factors such as permeability ratio, water cut, shutting down high permeability layers, production pressure difference, and change in crude oil viscosity in high permeability layers. The primary objective of this work is to reveal the mechanism of small-layer interference under different conditions, and clarify the influence of main control factors on the production of small-layer. The results show that the smaller the permeability ratio is, the weaker the difference in physical properties among layers along the vertical direction is. The reduction in the difference in seepage resistance decreases the dynamic interference among layers. The reduction in the water ratio among layers and shutting down high permeability layers can reduce the interlayer interference effectively. Increasing production pressure difference effectively improves the oil displacement efficiency of reservoirs with poor physical properties. A lower fluidity in the high permeability layers can effectively improve the oil displacement efficiency of other layers.
At present, more than 90% of China’s oil production equipment comprises rod pump production systems. Indicator diagram analysis of the pumping unit is not only an effective method for monitoring the current working condition of a rod pump production system but also the main way to prevent, detect, and rectify various faults in the oil production process. However, the identification of the pumping unit indicator diagram mainly involves manual effort, and the identification accuracy depends on the experience of the monitoring personnel. Automatic and accurate identification and classification of the pumping unit indicator diagram using new computer technology has long been the research focus of studies for monitoring the pumping unit working condition. In this paper, the indicator diagram is briefly introduced, and the AlexNet model is presented to distinguish the indicator diagram of abnormal wells. The influence of the step size, convolution kernel size, and batch normalization (BN) layer on the accuracy of the model is analyzed. Finally, the AlexNet model is improved. The improved model reduces the calculation cost and parameters, accelerates the convergence, and improves the accuracy and speed of the calculation. In the experimental analysis of abnormal well diagnosis, the data are preprocessed via data deduplication, binary filling, random line distortion, random scaling and stretching, and random vertical horizontal displacement. In addition, the image is expanded by transforming several well indicator diagrams. Finally, data sets of 10 types of indicator diagrams are created for better adaptability and application in the analysis and classification of indicator diagrams, and the ideal application effect is achieved in actual working conditions. In summary, this technology not only improves the recognition accuracy but also saves manpower. Thus, it has good application prospects in the field of oil production.
The productivity evaluation of CBM wells can yield significant insights into exploring the patterns of CBM production, predicting the effectiveness of the CBM well and reservoir stimulation, optimizing the gas reservoir development program, and developing a reasonable production system, for the purpose of facilitating efficient development of CBM. In particular, to accurately evaluate CBM productivity, we should establish the corresponding mathematical model of fluid flow through porous media and productivity evaluation model based on a clear understanding of CBM occurrence states and mechanisms of its flow through porous media. After considering the effects of slip flow, Knudsen diffusion, surface diffusion, stress sensitivity, and matrix shrinkage on fluid mass transfer, we have put forward a triple-porosity and dual-permeability mathematical model to predict CBM productivity that incorporates matrix gas desorption, complex flow in matrix pores, and gas–water two-phase flow in a cleat system. In combination with reservoir characteristic parameters, a case study of Ma-26 well in the Mabidong block in the south of the Qinshui Basin, we carried out a numerical simulation of the productivity of a fractured CBM well and analyzed the effects (on production performance) of occurrence states, cleat system permeability, complex flow regimes in the matrix, Langmuir pressure, and Langmuir volume on production are provided. The results show that 1) in the initial drainage and production stage of CBM wells, both free gas and adsorbed gas are produced simultaneously, while adsorbed gas dominates the production in later stages; 2) the peak output and cumulative output of CBM wells increase significantly with the rise in cleat system permeability; 3) the increase of Langmuir pressure, volume, and matrix porosity are conducive to the increase of CBM production. The research has considerable reference value for work on mechanisms of CBM flow in porous media and post fracturing productivity evaluation of CBM and also provides a theoretical basis for fieldwork in CBM development.
Deepwater gas fields have high bottom water energy and a high risk of seeing water. Higher requirements are put forward for the water control process to control the water effect. This article is based on the actual background and well design of the X gas field in the South China Sea and on three sets of physical simulation experiments and three sets of numerical simulation experiments. An analysis and comparison of the water control effect of a combination of continuous packer, continuous packer and variable density screen tube, and their adaptability evaluation in deepwater gas reservoirs were performed. The results obtained from the numerical and physical simulations are consistent. The experimental results show that the water control process of a continuous packer is mainly based on the water-seeing and water-blocking ability. It is less capable of extending the time to produce water in the horizontal section. However, its water-blocking ability is strong and is able to seal the water spot quickly. It extends the total production time by 12.29% and increases the total gas production by 5.96%; the combined water control process of the continuous packer and variable density screen tube can effectively play their respective advantages of water control. The combination of the continuous packer and variable density screen tube can effectively be advantageous of their respective water control processes, enabling the gas–water interface to advance in a balanced manner, extending the water-free gas recovery period by 11.61%, extending the total gas production time by 15.76%, and increasing the total gas production volume by 13.75%. Both water control processes have good applicability in deepwater gas fields and have certain sand control capability. It is conducive to the one-time completion operation for the commissioning of deepwater gas fields.