延川南煤层气田氮气扰动增产技术试验及效果分析

Nitrogen disturbance technology test and effect analysis in southern Yanchuan coalbed gas field

延川南煤层气田目前面临的主要问题是存在大量的低产低效井,产能没有得到充分释放。国内专家和学者对低产低效井增产的技术进行了大量研究,尝试了冲击波、氮气泡沫压裂等技术,但是成本高增产效果有限,在这些技术的研究基础上,设计出一种新的增产技术——氮气扰动技术,该技术目前正处于试验阶段。该技术在延川南煤层气田经过20多口井的试验,发现大多数低产低效井经过氮气扰动试验后大幅度增产,但停止试验后又恢复低产或停产,说明氮气扰动是一种增产辅助手段,可根据经济效益反复应用。氮气扰动技术适用于曾经水力压裂、裂缝通道较完整、初期产量较高、抽采周期短、递减率较高的低产低效井或停产井。氮气扰动是煤层气低产低效井增产改造的创新性技术,值得在延川南煤层气田进一步探索和应用推广。

Southern Yanchuan coal field faces main problem is that there are a large number of inefficient low-yielding wells,and the productivity has not been fully released.The research on stimulation technology of inefficient low-yielding wells has been going on.Various experts and scholars have done a lot of research such as shock wave,nitrogen foam fracturing and other technologies,but the cost is high and the yield is limited.On the basis of the research of these technologies,a new stimulation technology-nitrogen disturbance technology has been produced and is currently in the test stage.Recently,a new technology nitrogen disturbance technology has been obtained through the exploration of predecessors.The technology has been tested in more than 20 wells in South Yanchuan coalbed gas field,most of the inefficient low-yielding wells have been greatly increased after nitrogen disturbance test,but after stopping the test,return to low production or shut-down,which shows that nitrogen disturbance is an auxiliary means of increasing production and can be repeatedly applied according to economic benefits.Nitrogen disturbance technology is suitable for low production and low efficiency wells or lying down wells with hydraulic fracturing,complete fracture channel,high initial production,short pumping period and high decline rate.Nitrogen disturbance is an innovative technology for stimulation of low yield and low efficiency CBM wells,which is worthy of further exploration and application in Southern Yanchuan coal field.