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Drainage of irrigated land
Published in Willem F. Vlotman, Lambert K. Smedema, David W. Rycroft, Modern Land Drainage, 2020
Willem F. Vlotman, Lambert K. Smedema, David W. Rycroft
In all cases it holds that the economic feasibility of well drainage is considerably enhanced when the quality of the pumped water is good enough to be used for irrigation. Well drainage is therefore widely applied in fresh groundwater zones but not in saline groundwater zones. In the latter zones, pipe drainage is often preferred as streamlines go less deep and therefore mobilize less salt from the deeper layers. In zones with saline substrata, the effluent from pipe drainage is generally less saline than from well drainage, making it easier for the drainage water to be reused (e.g., when mixed with the irrigation water) or to dispose of it in an environmentally acceptable manner (see also section 16.5.2).
Transient modeling of plunger lift with check valve for gas well deliquification in horizontal well
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Youliang Jia, Shuqiang Shi, Wei Tian, Bo Tan, Yacong Yang, Xuri Li
Figure 8 depicts the instantaneous gas production and cumulative gas production curve. The instantaneous gas production rapidly increased when the gas well was opened. Subsequently, it gradually decreased until the gas production was stable. The well discharge liquid when the liquid column above the plunger reached the wellhead, the gas discharge channel was blocked, the instantaneous gas production curve fluctuated. The instantaneous gas production abruptly increased after the liquid was completely discharged. Subsequently, it gradually decreases, and finally it stabilized until it reached the shut-in stage. The calculated cumulative gas production of plunger lift with check valve was 5063 m3 compared with that of the actual cumulative gas production (4958 m3) in a cycle, and the relative error was 2.11%. Figure 9 demonstrates the instantaneous liquid production and cumulative liquid production curve. It can be observed from the Figure 8 that the duration of gas-well drainage was shorter than that of gas production. The predicted cumulative liquid production of the plunger lift with check valve in one cycle was 0.243 m3, and the relative was 4.29%. It can be observed from the above analysis that the calculated tubing pressure, gas production, and liquid production were in good agreement with that of actual measured value.
Study on foam transport mechanism and influencing factors in foam drainage gas recovery of natural gas well
Published in Journal of Dispersion Science and Technology, 2022
Bin Huang, Xiaohan Nan, Cheng Fu, Wanfu Zhou, Siqiang Fu, Tingwei Zhang
The four curve relationships in Figure. 12 illustrate that the liquid level height in the wellbore is linear with time under different influencing factors in the process of gas well drainage. Within the range of 0–3m3/d of daily production, the effect of daily output on liquid surface height is relatively small, and foaming efficiency has the greatest influence on liquid surface height. This shows that for foam drainage and gas recovery, how to produce foam efficiently is the main factor affecting the foam drainage efficiency. At present, the natural gas wells that use foam drainage can further improve the downhole foaming device or foaming agent to improve the liquid carrying efficiency of foam drainage and gas recovery, and then extend the application time of foam drainage and gas recovery and the recovery period of natural gas wells, which is of great significance to further improve the recovery of natural gas.
Absolute open flow (AOF) potential evaluation for watered-out gas wells in water-drive gas reservoir
Published in Petroleum Science and Technology, 2021
Xiaohua Liu, Fankun Meng, Qian Li, Zhenhua Guo, Weijun Shen, Chun Zhang
Here is a field example to show the procedure of deliverability analysis with production data. The initial reservoir pressure and temperature are 76 MPa and 140 °C, respectively. The density of gas and water at standard conditions, ρgsc and ρwsc, are 0.70 kg/m3 and 1000 kg/m3, respectively. From the inter-well spacing, the well drainage radius re is about 1500 m and default value of rw is 0.1 m. Based on PBU analysis, the skin factor S is −3 and non-Darcy flow coefficient D is 4 × 10−6(m3/d)−1 or 5.7 × 10−6(kg/d)−1. The watered-out gas well is producing with gas production rate qgsc = 30 × 104m3/d and water production rate qwsc = 100m3/d at well bottom-hole flowing pressure pwf = 59.30 MPa, and the current reservoir pressure is depleted to pR = 60.06 MPa. Figure 5 presents the lab tested gas–water relative permeability curve. Figure 6 is the relationship curve between two-phase pseudo-pressure and pressure, in which the pseudo-pressure at reservoir average pressure pR and well bottom-hole pressure pwf can be determined.