A fine control method of flowing pressure in single-phase flow section of high-rank CBM gas development wells: A case study from the Fanzhuang-Zhengzhuang Block in the Qinshui Basin

被引：0
|
作者：
Hu Q. [1 ]
Jia H. [1 ]
Qi K. [1 ]
Fan B. [1 ]
Yu J. [1 ]
Liu C. [1 ]
Xie L. [2 ]
Zhang Q. [1 ]
He J. [2 ]
机构：
[1] CBM Exploration and Development Branch, PetroChina Huabei Oilfield Company, Jincheng, 047000, Shanxi
[2] No.3 Oil Production Plant, PetroChina Huabei Oilfield Company, Hejian, 062400, Hebei
来源：
Natural Gas Industry | 2018年 / 38卷 / 09期
关键词：
Bottom hole flowing pressure; CBM wells; Fanzhuang-Zhengzhuang Block; Fine control method; High-rank coal; Production increase; Qinshui Basin; Single-phase flow; Water production law;
D O I：
10.3787/j.issn.1000-0976.2018.09.010
中图分类号：
学科分类号：
摘要：
The existing CBM well production control technologies don't take into consideration the effect of the variation of water supply amount of coal seams, so the frequency regulation of pumping unit is less effective and so often to result in the fluctuation of flowing pressure, and consequently reservoirs are damaged. In this paper, No.3 coal seam of Shanxi Fm, Lower Permian in the Fanzhuang-Zhengzhuang Block of the Qinshui Basin, was taken as the study object. After the water production laws of coal seams when a CBM well is in the stage of single-phase flow and the drainage laws of pumping unit system in a CBM well were investigated, a fine control method was determined for bottom hole flowing pressure by theoretically deriving the bottom hole flowing pressure control method based on water production laws of coal seams. Then it was tested on site. And the following research results were obtained. First, when a CBM well is in the stage of single-phase flow, daily water production increases linearly with the decrease of the bottom hole flowing pressure, and the slope is different due to the differences of reservoir physical properties. Second, it is the linear relationship between the theoretical displacement and the actual value of the pumping unit system in the new production wells, and the displacement coefficient is about 0.888. The daily water production of a CBM well in the stage of single-phase flow is proportional to the frequency of pumping unit. Third, the slope and intercept of the frequency-cumulative production time trend line of pumping unit under the reasonable daily pressure decline amplitude are determined by conducting field tests. During the production of gas wells, the actual daily pressure decline amplitude can be guaranteed to be equal to the reasonable value so long as the frequency of pumping unit strictly increases linearly with the increase of cumulative production time according to the reasonable slope. In conclusion, the bottom hole flowing pressure of the CBM wells in the stage of single-phase flow can be controlled precisely by virtue of this method, which plays an active role in promoting the high yield of CBM wells. © 2018, Natural Gas Industry Journal Agency. All right reserved.
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页码：76 / 81
页数：5
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