欠饱和煤层气藏临界解吸压力计算方法

doi:10.13809/j.cnki.cn32-1825/te.2022.04.006

摘要/Abstract

摘要：

为了探讨欠饱和煤层气藏临界解吸压力的物理意义,基于煤层气藏赋存状态,介绍了目前已有的传统临界解吸压力计算方法、液相吸附理论的计算方法以及矿场统计算法,讨论了在煤岩气相湿润前提下的“欠饱和”现象的来源。在修正的气相吸附基础上,解释了临界解吸压力与基质孔隙毛管压力的关系,得到了新的临界解吸压力计算方法。通过对比4种方法在误差分析、理论完备性以及可操作性的优缺点,认为提出的新计算方法理论较为完备、可操作性强、计算简便,并在实例计算中得出了合乎实际生产范围内的结果。由此可得到在煤岩气相润湿前提下,煤层气吸附平衡且临界解吸现象可解释为储层压力与毛管压力之间作用的结果,改进的气相吸附理论与临界解吸压力新计算方法值得进一步研究。

关键词: 煤层气, 临界解吸压力, 气相吸附, 毛管压力, 赋存方式

Abstract:

In order to investigate the physical meaning of critical desorption pressure in undersaturated CBM（coalbed methane） reservoirs, the traditional critical desorption pressure calculation method and the liquid phase adsorption theory commonly used in field are introduced based on the status of the reserves of CBM, and the origin of the “undersaturated” phenomenon under the premise of gas phase wet is discussed. On the basis of the modified gas phase adsorption, the relationship between the critical desorption pressure and the capillary pressure in matrix pores is explained, and a new calculation method of critical desorption pressure is obtained. By comparing the advantages and disadvantages of the four methods in error analysis, theoretical completeness and operability, it is considered that the new calculation method proposed is relatively complete in theory, has strong operability and is easy to calculate, and obtains a reasonable result in an example. It can be concluded that CBM adsorption equilibrium and critical desorption phenomenon can be interpreted as the result of the interaction between reservoir pressure and capillary pressure under the premise of coalbed gas phase wetting. The improved gas phase adsorption theory and the new calculation method of critical desorption pressure are worth the further study.

Key words: CBM（coalbed methane）, critical desorption pressure, gas phase adsorption, capillary pressure, storage state

中图分类号:

TE349

张斯,彭小龙. 欠饱和煤层气藏临界解吸压力计算方法[J]. 油气藏评价与开发, 2022, 12(4): 589-595.

ZHANG Si,PENG Xiaolong. Calculation method of critical desorption pressure in undersaturated CBM reservoirs[J]. Petroleum Reservoir Evaluation and Development, 2022, 12(4): 589-595.

图/表 9

图1

图2

图3

图4

图5

图6

表1

图7

图8

参考文献 22

[1]	秦勇, 刘焕杰, 范秉恒, 等. 山西南部上古生界煤层含气性研究Ⅲ.煤层气采收潜势分析[J]. 煤田地质与勘探, 1998, 26(1):28-32.
	QIN Yong, LIU Huanjie, FAN Bingheng, et al. The studies on gas-bearing characteristics of the upper paleozoic coal seams in the Southern Shanxi, China(Ⅲ). Recoverable potential of coalbed methane[J]. Coal Geology & Exploration, 1998, 26(1): 28-32.
[2]	赵嵘. 井下直接法测定煤层瓦斯压力数值模拟研究及工程指导[D]. 廊坊: 华北科技学院, 2017.
	ZHAO Rong. Numerical simulation research and engineering guidance of underground direct measurement of coal seam gas pressure[D]. Langfang: North China University of Science and Technology, 2017.
[3]	钱鸣皋. 介绍煤及瓦斯突出的性质与力学作用的现代学说[J]. 中国矿业大学学报, 1955, 1(3):92-100.
	QIAN Minggao. The modern theory of nature and mechanical action of coal and gas outburst is introduced[J]. Journal of China University of Mining and Technology, 1955, 1(3): 92-100.
[4]	王凯, 俞启香, 蒋承林. 钻孔瓦斯动态涌出的数值模拟研究[J]. 煤炭学报, 2001, 26(3):279-284.
	WANG Kai, YU Qixiang, JIANG Chenglin. Study of dynamic gas emission during boring process by using numerical simulation[J]. Journal of China Coal Society, 2001, 26(3): 279-284.
[5]	李晓伟. 复杂地质条件下石门及井筒揭煤突出危险性快速预测研究[D]. 徐州: 中国矿业大学, 2009.
	LI Xiaowei. Study on rapid prediction of uncovering coal outburst risk in Shimen and shaft under complex geological conditions[D]. Xuzhou: China University of Mining and Technology, 2009.
[6]	邵军. 关于煤屑瓦斯解吸经验公式的探讨[J]. 煤炭工程师, 1989, 16(3):21-27.
	SHAO Jun. Discussion on empirical formula of coal cinder gas desorption[J]. Coal Engineer, 1989, 16(3): 21-27.
[7]	杨振侠. 解吸法损失瓦斯量计算的探索[J]. 西部探矿工程, 1991, 3(2):33-36.
	YANG Zhenxia. Exploration of gas loss calculation by desorption method[J]. West-China Exploration Engineering, 1991, 3(2): 33-36.
[8]	李传亮, 朱苏阳, 彭朝阳, 等. 煤层气井突然产气机理分析[J]. 岩性油气藏, 2017, 29(2):145-149.
	LI Chuanliang, ZHU Suyang, PENG Zhaoyang, et al. Mechanism of gas production rate outburst in coalbed methane wells[J]. Lithologic Reservoirs, 2017, 29(2): 145-149.
[9]	周昀涵, 罗新荣, 吴丽丽, 等. 井下钻屑解吸瓦斯时瓦斯损失量的探讨[J]. 煤矿安全, 2012, 43(4):109-111.
	ZHOU Yunhan, LUO Xinrong, WU Lili, et al. Discussion of gas loss amount when underground drilling cuttings desorbed gas[J]. Safety in Coal Mines, 2012, 43(4): 109-111.
[10]	吴昊镪, 彭小龙, 朱苏阳, 等. 煤层气井煤粉成因、运移和防控研究进展[J]. 油气藏评价与开发, 2020, 10(4):70-80.
	WU Haoqiang, PENG Xiaolong, ZHU Suyang, et al. Research progress of coal fine formation, migration and control in CBM well[J]. Petroleum Reservoir Evaluation and Development, 2020, 10(4): 70-80.
[11]	肖翠, 王伟, 李鑫, 等. 基于现代产量递减分析的延川南煤层气田剩余气分布数值模拟研究[J]. 油气藏评价与开发, 2020, 10(4):25-31.
	XIAO Cui, WANG Wei, LI Xin, et al. Numerical simulation of residual gas distribution in CBM gas field of south Yanchuan based on advanced production data analysis[J]. Petroleum Reservoir Evaluation and Development, 2020, 10(4): 25-31.
[12]	朱苏阳, 李传亮, 杜志敏, 等. 煤层气的复合解吸模式研究[J]. 中国矿业大学学报, 2016, 45(2):319-327.
	ZHU Suyang, LI Chuanliang, DU Zhimin, et al. Compound desorption model of coalbed methane[J]. Journal of China University of Mining & Technology, 2016, 45(2): 319-327.
[13]	马东民. 煤层气吸附解吸机理研究[D]. 西安: 西安科技大学, 2008.
	MA Dongmin. Research on the adsorption and desorption mechanism of coalbed methane[D]. Xi'an: Xi'an University of Science and Technology, 2008.
[14]	欧成华, 李士伦, 杜建芬, 等. 煤层气吸附机理研究的发展与展望[J]. 西南石油学院学报, 2003, 25(5):34-38.
	OU Chenghua, LI Shilun, DU Jianfen, et al. Development and prospect on adsorption mechanism of coalbed methane in coal seams[J]. Journal of Southwest Petroleum Institute, 2003, 25(5): 34-38.
[15]	朱苏阳. 煤层气的吸附—解吸机理及应用研究[D]. 成都: 西南石油大学, 2018.
	ZHU Suyang. The mechanism and application studies on coalbed methane adsorption and desorption[D]. Chengdu: Southwest Petroleum University, 2018.
[16]	傅雪海, 秦勇, 韦重韬, 等. QNDN1井煤层气排采的流体效应分析[J]. 天然气工业, 2010, 30(6):48-51.
	FU Xuehai, QIN Yong, WEI Chongtao, et al. An analysis of fluid effect during coalbed met hane drainage in the well ONDNI[J]. Natural Gas Industry, 2010, 30(6): 48-51.
[17]	司庆红, 朱炎铭, 曹新款. 煤层气井排采初期井底压降的计算方法[J]. 中国煤层气, 2011, 8(1):37-39.
	SI Qinghong, ZHU Yanming, CAO Xinkuan. Calculation methods of well bottom-hole pressure drop in initial stage[J]. China Coalbed Methane, 2011, 8(1): 37-39.
[18]	张永生, 孙文卿, 高学通. 煤储层理论临界解吸压力与实际排采对比研究[J]. 山西焦煤科技, 2011, 35(1):4-7.
	ZHANG Yongsheng, SUN Wenqing, GAO Xuetong. Comparative study between theoretical critical desorption pressure and actual drainage and mining state of coal reservoir[J]. Shanxi Coking Coal Science & Technology, 2011, 35(1): 4-7.
[19]	彭泽阳. 考虑煤层气孔隙水储量计算与临界解吸压力确定方法[D]. 北京: 中国石油大学(北京), 2019.
	PENG Zeyang. Determination method for gas reserve and critical desorption pressure of coalbed methane by water effect[D]. Beijing: China University of Petroleum(Beijing), 2019.
[20]	李相方, 蒲云超, 孙长宇, 等. 煤层气与页岩气吸附/解吸的理论再认识[J]. 石油学报, 2014, 35(6):1113-1129. doi: 10.7623/syxb201406009
	LI Xiangfang, PU Yunchao, SUN Changyu, et al. Recognition of absorption/desorption theory in coalbed methane reservoir and shale gas reservoir[J]. Acta Petrolei Sinica, 2014, 35(6): 1113-1129. doi: 10.7623/syxb201406009
[21]	彭小龙, 费冬, 朱苏阳, 等. 煤层气吸附-解吸机理再认识[J]. 中国煤层气, 2019, 16(2):9-12.
	PENG Xiaolong, FEI Dong, ZHU Suyang, et al. Reconsideration of coalbed methane adsorption-desorption mechanism[J]. China Coalbed Methane, 2019, 16(2): 9-12.
[22]	周琦忠. 沁南樊庄区块煤层气井产气压力特征及其对产能的影响[D]. 徐州: 中国矿业大学, 2016.
	ZHOU Qizhong. Characteristics of gas production pressure and its influence on productivity in Fanzhuang Block of Southern Qinshui Basin[D]. Xuzhou: China University of Mining and Technology, 2016.

参数	传统气相吸附	液相吸附	井底流压反推	改进的气相吸附
误差	较多	一般	较多	一般
理论完备	一般	最好	一般	较好
可操作性	一般	一般	较差	最好