玉门油田白垩系特殊岩性储层的深度酸压技术研究与应用
RESEARCH AND APPLICATION OF DEEP ACID FRACTURING TECHNIQUE IN SPECIAL CRETACEOUS RESERVOIR OF YUMEN OILFIELD
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摘要: 玉门油田青西试采区白垩系下沟组油藏岩性特殊,属于陆源碎屑岩占35.15%、碳酸盐岩类占33.84%、粘土矿物占31.01%的特殊储层。储层低渗、低孔,天然裂缝发育,油层中部平均深度4200m,平均温度120℃。针对这种特殊岩性储层,通过薄片鉴定、X衍射、环境扫描电镜等分析,结合酸蚀导流能力模拟试验,油藏数值模拟及优化设计等研究成果,建立了既不同于纯碳酸盐岩储层的深度酸压,又不同于砂岩储层酸化解堵的组合技术,即"降阻酸深度酸压+多组分酸闭合酸化"的特殊增产技术方法,优选了适合储层改造的液体体系。通过柳102井的现场实践,取得了增产102t/d、增产倍数达10倍的显著效果。Abstract: The lithology of Cretaceous Xiagou Formation reservoir in Qingxi long term production block of Yumen Oilfield is particular:terrigenous elastic rock takes 35.16%,carbonate rock 33.84% and clay mineral 31.01%.The permeability is low,porosity is low,and the natural fractures are developed.The average depth of the middle reservoir is 4200 m,the average temperature is 120℃.For the particular lithologic reservoir,through analysis of slice appraisal,X-diffraction,scanning electron microscope and so on,combining them with the research results like acid etching diversion capacity simulation test,reservoir numeric simulation and optimized design,this paper presents a particular stimulation process-deep acid fracturing with friction reducing acid plus closed acidizing with multi-component acid.This paper also presents the liquid sys-tern suitable for reservoir reforming.Field application of this process in well Liu102 shows that the stimulation effect is obvious:oil is increased by 102 t per day,and the multiple of incremental oil recovery is 10.