煤层气井产水差异性原因分析及其对产气量的影响
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摘要
本文以沁水盆地长治地区李村区块为例,利用该区141口煤层气井排采动态资料及相关的地质资料,明确了产水来源及断裂发育程度是导致产水差异性大的主要原因,并在此基础上分析了其对产气量的影响,研究结果表明:①高产水井受断裂构造影响,水动力条件活跃,在水力冲洗作用下,吸附气易发生溶解-运移,导致含气性遭受破坏,影响产气量。②高产水排水降压难度大,对排采设备要求高,产能释放困难。③呈片分布的高产水与邻井协同降压作用明显,高产水井对相邻产气井具有助排作用。
Taking the Licun Block in Changzhi area of Qinshui Basin as an example, using the production dynamic data and related geological data of 141 coalbed methane wells in the area, it is clear that the source of water and the degree of fault development are the main reasons for the large difference in water production. Based on this, the influence of water production difference on the gas production is analyzed. The results show that: first, the wells with high water production are affected by fault structure and the hydrodynamic conditions are active. Under the action of hydraulic flushing, the adsorbed gas is prone to dissolution-transport, resulting in the damage to the gas-bearing properties, which will affect the gas production. Second, it is difficult to drain water and reduce the pressure in this kind of wells, the requirements for the drainage equipment are high, and the production capacity is difficult to release. Third, the wells with high water production which are distributed in groups have obvious synergistic effect on the adjacent well, and these wells have the assisting effect on the gas production of their adjacent wells.
Taking the Licun Block in Changzhi area of Qinshui Basin as an example, using the production dynamic data and related geological data of 141 coalbed methane wells in the area, it is clear that the source of water and the degree of fault development are the main reasons for the large difference in water production. Based on this, the influence of water production difference on the gas production is analyzed. The results show that: first, the wells with high water production are affected by fault structure and the hydrodynamic conditions are active. Under the action of hydraulic flushing, the adsorbed gas is prone to dissolution-transport, resulting in the damage to the gas-bearing properties, which will affect the gas production. Second, it is difficult to drain water and reduce the pressure in this kind of wells, the requirements for the drainage equipment are high, and the production capacity is difficult to release. Third, the wells with high water production which are distributed in groups have obvious synergistic effect on the adjacent well, and these wells have the assisting effect on the gas production of their adjacent wells.
引文
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[4] 王金,康永尚,姜杉钰,等.沁水盆地寿阳区块煤层气井产水差异性原因分析及有利区预测[J].天然气工业,2016,36(8):52-58.
[5] 李清,赵兴隆,等延川南区块煤层气井高产水成因分析及排采对策[J].石油钻探技术,2013,41(6):95-99.
[6] 田文广,邵龙义,孙斌,等.保德地区煤层气井产出水化学特征及其控气作用[J].天然气工业,2014,34(8):15-19.
[2] 张星.毕义泉,汪庐山,等.黏土矿物膨胀机理及防膨研究现状[J].精细石油化工进展,2014,15(5):39-43.
[3] 王勃,巢海燕,郑贵强,等.高、低煤阶煤层气藏地质特征及控气作用差异性研究[J].地质学报,2008,82(10):1396-1400.
[4] 王金,康永尚,姜杉钰,等.沁水盆地寿阳区块煤层气井产水差异性原因分析及有利区预测[J].天然气工业,2016,36(8):52-58.
[5] 李清,赵兴隆,等延川南区块煤层气井高产水成因分析及排采对策[J].石油钻探技术,2013,41(6):95-99.
[6] 田文广,邵龙义,孙斌,等.保德地区煤层气井产出水化学特征及其控气作用[J].天然气工业,2014,34(8):15-19.