负压开采与泡沫排水复合采气工艺在致密砂岩气藏的应用

Application of the composite gas production technology to tight sandstone gas reservoirs: Negative-pressure production and foam-assisted dewatering

肖庆华 文涛 粟超

XIAO Qinghua WEN Tao SU Chao

中国石油川庆钻探工程有限公司地质勘探开发研究院 四川恒溢石油技术服务有限公司

Research Institute of Geological Exploration and Development, CNPC Chuanqing Drilling Engineering Co., Ltd., Chengdu 610051, Sichuan, China Sichuan Hengyi Petroleum Technical Services Ltd., Chengdu 610051, Sichuan, China

为提高苏里格致密砂岩气藏气水同产井在低压、低产阶段排采效果，提出了负压开采与泡沫排水复合采气工艺。通过对典型区块气井单位压降产量、低压低产阶段剩余可采储量和生产系统节点分析，对复合工艺适应性进行了研究，结合适应性研究结果、复合工艺增产原理及负压开采设备关键参数制定了复合工艺选井原则，并优选了3口井进行现场试验。结果表明：复合工艺对低压、低产阶段不能正常携液生产的气井具有较好的适应性，当井口油压降至0 MPa时，能使气井产量在0.2×10⁴ m³/d左右时仍正常携液生产，在泡沫排水的基础上可进一步降低停喷地层压力。优选Ⅰ类、Ⅱ类、Ⅲ类3口试验井，措施期间日均增气量分别为0.50×10⁴ m³/d、0.39×10⁴ m³/d、0.28×10⁴ m³/d，能将井口油压最低降至−0.05 MPa，可见复合工艺能有效降低气井井口压力，释放气井产能，同时储层品质越好的气井复合工艺应用效果越好。

To improve the drainage performance of the low-pressure low-rate wells with co-production of gas and water in the Sulige tight sandstone gas reservoir, the composite gas production technology of negative-pressure production and foam-assisted dewatering was developed. The applicability of the composite production technology was analyzed in accordance with the gas production of wells per unit drawdown pressure, remaining recoverable reserves in the low-pressure low-rate production stage and production system nodal analysis of the representative Sulige block. Moreover, the well candidate criteria were proposed for the composite production technology, considering the applicability analysis, production stimulation mechanisms and key parameters of the negative-pressure production equipment, and field testing was performed in three wells selected correspondingly. The results showed that the presented technology is highly applicable to gas wells that can no maintain normal commingled flow of water and gas in the case of low pressure and low production rates. As the tubing pressure at the wellhead drops to zero, normal mixed flow of water and gas can be maintained even with the gas production of about 0.2×10 m/d. The quit-flowing pressure can be further lowered, with the help of foam-assisted dewatering. Three wells of Type-Ⅰ, Ⅱ and Ⅲ, respectively were selected for field testing. The average daily production gains were 0.50×10 m/d, 0.39×10 m/d and 0.28×10 m/d respectively during the testing, and the minimal wellhead tubing pressure reached −0.05 MPa. Hence, the composite production technology can effectively lower down wellhead pressure of gas wells and tap the gas production potential. Also, better performance of the presented production technology is expected in reservoirs with higher quality.

10.13639/j.odpt.202206042