新疆油田火山岩气藏体积压裂机理研究及应用

进行火山岩气藏压裂改造时,通常采用形成单一裂缝的增产改造技术,气井稳产时间较短.借鉴页岩气开发理念,深入研究火山岩气藏体积压裂机理.根据缝内压力传导的力学模型,研究不同液体体系对压力传导的影响,分析无滤饼压裂液体系对体积压裂的作用,优选出压裂液体系;建立不同角度天然裂缝开启的力学模型,确立体积形成的关键力学条件,并针对火山岩气藏压裂目的层的地应力结构进行实际分析.从储层矿物角度出发,研究对比火山岩储层的脆性系数;根据力学条件,结合压裂工艺过程,建立相关模型,优化研究体积压裂关键工艺参数,包括排量、压裂规模等；分析降阻水、线性胶、浓胶液三种不同黏度液体对裂缝网络的作用.在上述研究基础上,针对新疆油田DX1413井实际地质条件,分析该井进行体积压裂的有利条件,并进行压裂设计与改造施工,对施工曲线、施工过程、施工结果进行分析,得到了一些有益的结论,这些结论对火山岩气藏的开发有重要的启迪作用.

Research and Application of Volume Fracturing Mechanism on Volcanic Gas Reservoir in Xinjiang Oil Field

When volcanic gas reservoir is stimulated,the technology of forming a single long fracture is usually used to increase production in hydraulic fracturing,and the period of stabilized production of the gas well is comparatively short.Some idea is borrowed from that in exploitation of the shale gas,the volume fracturing mechanism of the volcanic gas reservoir is researched thoroughly.The impact of different liquid systems on pressure conduction is researched based on mechanical model of pressure conduction in the fractures.The action of non-filter cake fracturing fluid system on the volume hydraulic fracturing is analyzed,and then the best fracturing fluid system can be selected.The mechanical model of natural fracture opening with different angles is founded,and then the key mechanics conditions forming volume can be established.Terrestrial stress structure of the target zone of the hydraulic fracturing in the volcanic gas reservoir is analyzed.Friability coefficient of the volcanic rock reservoir is researched and contrasted on the analogy of producing reservoir′s mineral.In the light of mechanics condition,the correlation model is made considering the process of fracturing technology.Those crucial processing parameters of the volume hydraulic fracturing are optimized including discharge capability,hydraulic fracturing scale and so on.The effect of three liquids with different viscosity of drag reduction water,linear glue and deeper glue liquor on fracture network is analyzed.Based on the previous research,the favorable terms of the volume fracturing in DX1413 gas well are analyzed according to its actual geological conditions.At last,the curve,course and results of the operation are analyzed after the fracture design and stimulation.Some beneficial conclusion is drawn,which has important enlightenment action to exploitation of the volcanic gas reservoir.