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

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。

RESEARCH AND APPLICATION OF DEEP ACID FRACTURING TECHNIQUE IN SPECIAL CRETACEOUS RESERVOIR OF YUMEN OILFIELD

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.