中国石油大学学报（自然科学版）2017，Vol.41Issue(6)：117-122,6.DOI:10.3969/j.issn.1673-5005.2017.06.014
煤层气井近井压裂裂缝充填特征与堵塞机制
Filling characteristics and plugging mechanisms of hydraulic fractures near CBM vertical wells
摘要
Abstract
Particle migration and blocking in fracturing fractures near wellbore area can be one of the important factors to pro-duction reduction of coalbed methane ( CBM) wells. It is essential to reveal the filling characteristics and plugging mecha-nism of fracturing fractures in order to remove the plug and increase production. In this study, based on the in-site observa-tions of the fractures appeared in tunnels of underground coal mines, the filling characteristics and blocking mechanisms in the fractures of vertical CBM wells in southern Qinshui Basin were investigated. The observation shows that the fillings con-tain coal fines, proppant and well completion filter cake in the fractures near wellbore. Completion filter cake can control the initiation and propagation of fractures, and proppant distribution, and it can reduce the filtration rate of fracturing fluid. But when the fluid flows through the location where the filter cake is pinched out, significant fluid-loss can occur, which can take off sands and form sand wedge, and further the wedges become compacted and filled with coal fines carried by gas-liquid phase flow, then blocking or plugs of the fractures can be formed, reducing the flow capacity of the fracture seriously. It pro-poses that, based on a particle gathering model and the golden filtration principle, the size of proppants used in fracturing should be greater than 0. 900 mm in order to reduce the plugging coal fines with median size of 0. 045 mm that found in the study CBM area.关键词
煤层气井/压裂裂缝/完井滤饼/煤粉运移/堵塞Key words
coalbed methane wells/hydraulic fracture/completion filter cake/coal fines migration/plugging分类
天文与地球科学引用本文复制引用
陈立超,王生维,何俊铧,李瑞,刘建华,吕帅锋..煤层气井近井压裂裂缝充填特征与堵塞机制[J].中国石油大学学报（自然科学版）,2017,41(6):117-122,6.基金项目
山西省煤层气联合基金项目(2016012007) （2016012007）
内蒙古自然科学基金项目(2016MS0402) （2016MS0402）
内蒙古自治区高等学校科学研究项目(NJZY16090) （NJZY16090）
甘肃省油气资源研究重点实验室开放基金项目(SZDKFJJ20160606) （SZDKFJJ20160606）
内蒙古工业大学科学研究项目(X201534) （X201534）
