摘要
水平井多级压裂和储层低孔低渗特性使页岩气呈现长期的瞬态线性流,吸附气的解吸和纳米级基质孔隙中气体的滑脱效应使页岩气藏的产气规律不同于常规气藏。基于瞬态线性流和吸附气解吸的特点,考虑基质孔隙中气体的滑脱效应,建立并求解页岩气多级压裂水平井产能评价模型。在此基础上,通过数值反演和计算机编程绘制页岩气多级压裂水平井产量典型曲线,总结出页岩气多级压裂水平井包含裂缝线性流、双线性流、基质线性流和边界效应4个流动阶段。参数敏感性分析发现储容比、窜流系数、气藏尺寸对典型曲线的影响较大。通过分析滑脱效应对产能的影响,得到滑脱效应考虑与否的判定图版,对页岩气产能模型的选择具有指导意义。
Multi-stage fracturing of the horizontal wells and low porosity and permeability characteristics of the reservoirs make shale gas present a long-period transient linear flow in production, the absorbed gas desorption and the gas slippage effect in nano-pore matrix make shale-gas producing laws different from the conventional ones. Based on the features of the transient linear flow and desorption, considering the slippage effect, the production forecasting model for these kinds of horizontal wells is established and calculated. On the basis of the above, through the numerical inversion and computer programming, the typical curves of the well production are drawn. And furthermore four flow stages are summarized in the production of multi-stage fractured horizontal shale-gas wells： linear flow in fractures, bilinear flow, linear flow in matrix and boundary-dominated flow. The parameter sensitivity analyses show that the storativity ratio, interporosity flow coefficient and gas reservoir sizes possess more significant effects on the shapes of the typical curves. Through analyzing the effects of the gas slippage on the gas productivity, the identif- ying chart boards considering the effects or not are obtained. All the achievements gained above have a certain references to lhe selection of shale-gas productivity evaluation models.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2013年第3期157-163,共7页
Petroleum Geology & Oilfield Development in Daqing
基金
国家自然科学基金(50974128)
国家重大基础研究发展计划(973计划)项目(2009CB219606)
国家科技重大专项课题(2011ZX05038-4)
关键词
页岩气
多级压裂
水平井
产能评价
滑脱效应
储容比
窜流系数
气藏尺寸
shale gas
muhi-stage fracturing
horizontal well
productivity evaluation
slippage effect
storativity ratio
interporosity flow coefficient
gas reservoir size
