天然气工业2017，Vol.37Issue(6)：46-54,9.DOI:10.3787/j.issn.1000-0976.2017.06.007
沁水盆地樊庄—郑庄区块高煤阶煤层气水平井开采中的问题及对策
Problems in the development of high-rank CBM horizontal wells in the Fanzhuang-Zhengzhuang Block in the Qinshui Basin and countermeasures
摘要
Abstract
Coal reservoirs in the Qinshui Basin are characterized by high thermal evolution degree,low permeability,low reservoir pressure,lower gas saturation and strong heterogeneity,so its coalbed methane (CBM) development is quite difficult.In this paper,the development practice of high rank CBM horizontal wells in the Fanzhuang-Zhengzhuang Block was analyzed in terms of geological and engineering factors to clarify the productivity influencing factors,suitable geological conditions and potential tapping countermeasures of multi-lateral horizontal wells.It is shown that the reasons for the low development efficiency of multi-lateral horizontal wells are divided into three types.The first one is geological factor,such as encountering low CBM content areas or faults.The second is engineering factor,such as drilling fluid contamination,drilling collapse,drainage collapse and dust coal blockage.The third is the combination of both factors.It is concluded that encountering low CBM content areas and faults,collapse and blockage are the main reasons for the low production of multi-lateral horizontal wells in the Zhengzhuang-Fanzhuang Block,with the CBM content higher than 20 m3/t,the ratio of critical desorption pressure and reservoir pressure higher than 0.7 and vitrinite reflectance (Ro) higher than 3.8.The prerequisite for an open-hole horizontal well in this area to produce CBM at a high rate is that the well lies in the tensile stress zone.Finally,the countermeasures to tap the potential of some inefficient wells were put forward.First,the inefficient wells which are blocked with dust coal or collapsed in the later stage should be stimulated based on classifications.And second,it is necessary to explore new types of horizontal wells so as to deal with borehole collapse and continue the operation in the later stage by using tree-like roof horizontal wells,single-branch horizontal wells with casing or screen completion and fish-bone horizontal wells.关键词
高煤阶煤层气/水平井/开发效果/评价/挖潜对策/沁水盆地/樊庄—郑庄区块Key words
High-rank coalbed methane/Horizontal well/Development effect/Evaluation/Potential tapping countermeasure/Qinshui Basin/Fanzhuang-Zhengzhuang Block引用本文复制引用
张永平,杨延辉,邵国良,陈龙伟,魏宁,张利文..沁水盆地樊庄—郑庄区块高煤阶煤层气水平井开采中的问题及对策[J].天然气工业,2017,37(6):46-54,9.基金项目
国家科技重大专项“山西沁水盆地煤层气水平井开发示范工程”(编号:2011ZX05061). （编号:2011ZX05061）
