低渗透气藏开发过程中普遍存在非线性渗流,研究非线性渗流对采收率影响对于合理开发此类气藏具有一定意义。选取塔里木某低渗透气藏的岩心开展不同渗透率和含水饱和度条件下的非线性渗流实验,实验表明低渗透气藏存在启动压力梯度和较强的应力敏感性。渗透率越低、含水饱和度越高,启动压力梯度越大,应力敏感性越强,非线性渗流特征越明显。非线性渗流对低渗透气藏采收率有较大影响。启动压力梯度越大、应力敏感性越强的气藏,最终地层废弃压力越高,采收率越低。在低渗透气藏开发部署时,尽量寻找较高渗透率和较低含水饱和度的储层,优先开发。同时,井网加密调整、储层改造、降低含水饱和度也是提高低渗透气藏采收率的有效途径。
Non-linear seepage generally exists in the development of low permeability gas reservoirs. It is meaningful to study the effect of non-linear seepage on recovery factors for reasonably exploiting these low permeability gas reservoirs. Cores from the Tarim gas field are adopted and non-linear seepage experiments are conducted under different permeabilities and different water saturations. The experiment results show that low permeability gas reservoirs exhibit a start-up pressure gradient and strong stress sensitivity. The lower the permeability and the higher the water saturation, the larger the start-up pressure gradient, the stronger the stress sensitivity, and the more obvious the non-linear seepage behavior. Non-linear seepage impacts the recovery factor of low permeability gas reservoirs strongly. With the increase of start-up pressure gradient and stress sensitivity, the abandonment pressure of the gas field rises, and the recovery factor declines. During the development and deployment of low permeability gas reservoirs, the area with high permeability and low water saturation should be exploited firstly. Furthermore, well pattern infilling, reservoir stimulation and reducing water saturation are the effective methods to improve the recovery factor of low permeability reservoirs.
[1] 郭平, 张茂林, 黄全华, 等. 低渗透致密砂岩气藏开发机理研究[M]. 北京: 石油工业出版社, 2009. Guo Ping, Zhang Maolin, Huang Quanhua, et al. Low permeability tight sandstone gas reservoir development mechanism[M]. Beijing: Petroleum Industry Press, 2009.
[2] 公言杰, 柳少波, 姜林, 等. 致密砂岩气非达西渗流规律与机制实验研究——以四川盆地须家河组为例[J]. 天然气地球科学, 2014, 25(6): 804-809. Gong Yanjie, Liu Shaobo, Jianglin, et al. Experimental study of seepage characteristic and mechanism in tight gas sands: A case from xujiahe reservoir of Sichuan basin[J]. Natural Gas Geoscience, 2014, 25(6): 804-809.
[3] 熊健, 黄亮, 崔玲. 非线性流下井筒压降影响的水平井产能分析[J]. 科技导报, 2012, 30(35): 33-38. Xiong Jian, Huang Liang, Cui Ling. Effect of wellbore pressure drop on the horizontal well productivity with non-linear seepage[J]. Science & Technology Review, 2012, 30(35): 33-38.
[4] Fulton P F. The effect of gas slippage on relative permeability measure-ments[J]. Producers Monthly, 1951, 15(12): 14-19.
[5] 朱光亚, 刘先贵, 李树铁, 等. 低渗气藏气体渗流滑脱效应影响研究 [J]. 天然气工业, 2007, 27(5): 44-47. Zhu Guangya, Liu Xiangui, Li Shutie, et al. A study of slippage effect of gas percolation in low permeability gas pools[J]. Natural Gas Indus-try, 2007, 27(5): 44-47.
[6] 罗瑞兰, 程林松, 朱华银, 等. 研究低渗气藏气体滑脱效应需注意的问题[J]. 天然气工业, 2007, 27(4): 92-94. Luo Ruilan, Cheng Linsong, Zhu Huayin, et al. Problems on the study of slippage effect in low permeability[J]. Gas Reservoirs Natural Gas In-dustry, 2007, 27(4): 92-94.
[7] 于忠良, 熊伟, 高树生, 等. 致密储层应力敏感性及其对油田开发的影响[J]. 石油学报, 2007, 28(4): 95-98. Yu Zhongliang, Xiong Wei, Gao Shusheng, et al. Stress sensitivity of tight reservoir and its influence on oilfield development[J]. Acta Petro-lei Sinica, 2007, 28(4): 95-98.
[8] 王新海, 宋岩, 王玮, 等. 塔里木油田砂岩储层压力敏感系数变化规律研究[J]. 钻采工艺, 2008, 31(1): 66-67. Wang Xinhai, Songyan, Wangwei, et al. Variation law of coeeficient of sensitivity to pressure in sandstone reservoir in tarm oilfield[J]. Drill-ing& Production Technology, 2008, 31(1): 66-67.
[9] 赵明跃, 王新海, 雷霆, 等. 储层参数压力敏感性研究[J]. 油气井测试, 2001, 10(4): 3-4. Zhao Mingyue, Wang Xinhai, Lei Ting, et al. Study on sensitivity to pressure on reservoir factors[J]. Well Testing, 2001, 10(4): 3-4.
[10] 李士伦. 天然气工程[M]. 北京: 石油工业出版社, 2000. Li Shilun. Gas engineering[M]. Beijing: Petroleum Industry Press, 2000.
[11] 田冷, 李杰, 何顺利, 等. 储层流动单元划分方法在苏里格气田的应用[J]. 天然气工业, 2005, 25(10): 44-46. Tian Leng, Li Jie, He Shunli, et al. Application of the division method of reservoir flow unit in sulige gas field[J]. Natural Gas Industry, 2005, 25(10): 44-46.
[12] 毛美丽, 李跃刚, 王宏, 等. 苏里格气田气井废弃产量预测[J]. 天然气工业, 2010, 30(4): 64-66. Mao Meili, Li Yuegang, Wang Hong, et al. Prediction of gas well aban-donment production in the Sulige gas field[J]. Natural Gas Industry, 2010, 30(4): 64-66.
[13] 李涛, 王乐之. 天然气藏可采储量标定新思路及增加可采储量的技术途径[J]. 断块油气田, 2000, 7(4): 45-47. Li Tao, Wang Lezhi. Thought of recoverable reserves calibration for natural gas and technical method to improve recoverable reserve[J]. Fault-block Oil & Gas Field, 2000, 7(4): 45-47.
[14] 黄全华, 王富平, 尹琅, 等. 低渗气藏气井产能与动态储量计算方法 [M]. 北京: 石油工业出版社, 2012. Huang Quanhua, Wang Fuping, Yin Lang, et al. The computing meth-ods of productivity and dynamic reserves for low permeability gas res-ervoirs[M]. Beijing: Petroleum Industry Press, 2012.
