低渗气田压裂气井合理产量的确定

Confirming reasonable production of fractured gas wells in low permeability gas field

万怡妏 李治平 周金应

WAN Yi-wen LI Zhi-ping ZHOU Jin-ying

中国地质大学, 北京 100083

China University of Geosciences, Beijing 100083, China

低渗透气藏如果压裂后配产不合理,将导致出砂、裂缝闭合等不利情况,达不到增产的目的。综合考虑影响低渗压裂气井出砂产量的各方面因素,运用质点动力学的方法,建立了裂缝中存在压裂砂情况下的临界气流速度公式,只要气井产量小于该临界产量就不会破坏裂缝中的支撑砂粒,能使裂缝保持长期的有效性。得出裂缝宽度、裂缝高度、支撑剂砂粒直径、支撑剂砂粒密度及气体密度是影响压裂气井产量的因素。研究了保持压裂裂缝导流能力的最大生产产量的确定方法,能使裂缝保持长期的有效性,为矿场的合理生产奠定基础。通过对Cq气田某井的计算分析,表明所建立的模型是正确合理的。

Sand production and fracture closure will by caused by the unreasonable production of low permeability after fracturing.So the production of low permeability will not increase.This paper based on considering all the factors of sanding and applying the method of particle dynamics,establishes the critical gas flow velocity formula.The propping sand in the fracture will not be damaged if the output of gas well is less than the critical output,making the fracturing be available for a long time.In addition,the factors that influence the production of fractured gas wells are determined,such as the fracture width,fracture height,propping sand diameter,propping sand density,and gas density.It also researches the method to determine the largest output for keeping fracture flow capacity,laying a solid foundation for the reasonable production of gas field.According to the analysis of a well in cp gas field,it proves that the formula established above is reasonable.

10.3969/j.issn.1000-7393.2007.01.033