The Numerical Simulation of Hydraulic Transmission in the Process of Coalbed Methane (CBM) Wells Drainage in the South Block of Shizhuang

2013 ◽  
Vol 318 ◽  
pp. 541-546
Author(s):  
Xiang Hao Wang ◽  
Yan Bin Wang ◽  
Sha Sha Gao ◽  
Jia Hui Cheng ◽  
Hui Jie Xu ◽  
...  

Based on the data of CBM vertical well’s exploration and development in the south block of Shizhuang. This paper applies the method of comparison and adopts the software Visual Modflow4.2. The software simulated the 8th well whose original permeability and modified permeability is both poor and the groups of wells when draining for the rule of hydrostatic transmission. Results show that the relationship between original permeability and modified permeability determine the track of hydraulic transmission. When single well is draining, the hydraulic transmission can be seen as several concentric circles whose center is wellbore, but when the groups of wells are draining, regularity is the change of water level is not obvious because of the heterogeneity of coal reservoir. After draining for a long time, the water level difference between drained area and not drained area has appeared. The potential energy of underground water has a trend that overall downward, but did not form effective interference between the wells. Therefore, the original permeability and modified permeability become the key factor whether a region has high yield or not.

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jinkuang Huang ◽  
Shenggui Liu ◽  
Songlei Tang ◽  
Shixiong Shi ◽  
Chao Wang

Coalbed methane (CBM) has been exploited in the deep area of the coal reservoir (>1000 m). The production of CBM vertical wells is low because of the high in situ stress, large buried depth, and low permeability of the coal reservoir. In this paper, efficient and advanced CBM development technology has been applied in the Libi Block of the Qinshui Basin. According to the characteristics of the coal reservoir in the Libi Block, the coiled tubing fracturing technology has been implemented in four cluster horizontal wells. Staged fracturing of horizontal wells can link more natural fracture networks. It could also expand the pressure drop range and control area of the single well. This fracturing technology has achieved good economic results in the Libi Block, with the maximum production of a single horizontal well being 25313 m3/d and the average single well production having increased by more than 60% from 5000 m3/d to 8000 m3/d. Based on the data regarding the bottom hole pressure, water production, and gas production, the production curves of four wells, namely, Z5P-01L, Z5P-02L, Z5P-03L, and Z5P-04L, were investigated. Furthermore, a production system with slow and stable depressurization was obtained. The bottom hole pressure drops too fast, which results in decreasing permeability and productivity. In this work, a special jet pump and an intelligent remote production control system for the CBM wells were developed; hence, a CBM production technology suitable for the Libi Block was established. The maximum release for the CBM well productivity was obtained, thus providing theoretical and technical support for CBM development with geological and engineering challenges.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 644 ◽  
Author(s):  
Xinlu Yan ◽  
Songhang Zhang ◽  
Shuheng Tang ◽  
Zhongcheng Li ◽  
Yongxiang Yi ◽  
...  

Due to the unique adsorption and desorption characteristics of coal, coal reservoir permeability changes dynamically during coalbed methane (CBM) development. Coal reservoirs can be classified using a permeability dynamic characterization in different production stages. In the single-phase water flow stage, four demarcating pressures are defined based on the damage from the effective stress on reservoir permeability. Coal reservoirs are classified into vulnerable, alleviative, and invulnerable reservoirs. In the gas desorption stage, two demarcating pressures are used to quantitatively characterize the recovery properties of permeability based on the recovery effect of the matrix shrinkage on permeability, namely the rebound pressure (the pressure corresponding to the lowest permeability) and recovery pressure (the pressure when permeability returns to initial permeability). Coal reservoirs are further classified into recoverable and unrecoverable reservoirs. The physical properties and influencing factors of these demarcating pressures are analyzed. Twenty-six wells from the Shizhuangnan Block in the southern Qinshui Basin of China were examined as a case study, showing that there is a significant correspondence between coal reservoir types and CBM well gas production. This study is helpful for identifying geological conditions of coal reservoirs as well as the productivity potential of CBM wells.


2018 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Chia-Nan Wang ◽  
Dinh-Chien Dang ◽  
Nguyen Van Thanh ◽  
Pham Ky Quang

The current situation in Vietnam is that patients with their illness can easily go to drugstores to buy medicine by their own prescriptions or drugstore ones. This exists for a long time. This research is not focus on the ways to combat this phenomenon, but we aim to study the factors that are affecting behaviors of patients in choosing drugstores in the South of Vietnam. We employed both quantitative and qualitative methodologies for this research; 400 people responded to survey questions and 10 people involved in interviews. Briefly analysis from quantitative study showed that the affected factors are price and process, which is convenient, and people answered to interview agreed that price and product are the important factors for them to go to drugstores. Hence, the sales and policies makers should pay attention to the needs of customers in doing business of drugstores.


2019 ◽  
Vol 116 (32) ◽  
pp. 16121-16126 ◽  
Author(s):  
Ying Zhang ◽  
Yan Xiong ◽  
Renyi Liu ◽  
Hong-Wei Xue ◽  
Zhenbiao Yang

Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.


2013 ◽  
Vol 373-375 ◽  
pp. 743-751
Author(s):  
Wen Li ◽  
Xiao Mei Wang ◽  
Xue Ke Luo

In order to solve data lack of underground water research and monitoring situation, a wide range underground water lever dynamic information monitoring network system was designed. Remote monitoring terminal based on the techniques of embedded and wireless transmission monitored the change of underground water level; Monitoring analysis center based on the JAVA technology of B/S architecture was designed to inquiry the real-time data,set parameter and analyze data, etc. An approximate water level point was obtained by adopting the modified small period prediction model and the weight distribution method. This enhances reliability of monitored data. By utilizing the technology of GPRS wireless data transmission and Ethernet technology, a remote and real-time data transmission channel was build. Large area application in Shanxi Province shows that the system has the stable performance and the reasonable structure. System can provide long-term reliable data for underground water research.


2018 ◽  
Vol 38 (1) ◽  
pp. 8-15
Author(s):  
Salim Etsouri ◽  
Ferhat Kaci ◽  
Mohamed Bouaziz

The Continental intercalary groundwater is highly sought for its water as resources hugely mobilized in Northern Sahara. A very high flow rate and output pressure characterizes this underground water. It amounts from 50 to 400 l.s-1 for the flow, and from 5 to 40 bar for pressure. A survey of the Northern Sahara Aquifer System was essential to prove the existence of this potential. This energy appears into the artesian form, which remains very considerable for a very long time in most drilling. We have realised that this energy is immense, as well as the expanded volume of the groundwater, and the importance of its use in agriculture. Unfortunately, this potential remains untapped to this day and the energy of this water is completely neglected. Several turbo generator and/or inverted pump (PATs) integration tests were undergone. The new concept of reflection with respect to the environment and sustainable development has led us to structure our work towards the extension of this potential in order to extract the exploitable energy.


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